High Voltage SwitchedSwitched-Mode Power Supply for ThreeThree-Phase AC Aircraft Systems A Senior Project Presented to The Faculty of the Electrical Engineering Department California Polytechnic State University, San Luis Obispo In Partial Fulfillment Of the Requirements for the Degree Bachelor of Science By John Brewer, Jr. And Kamaljit Bagha June, 2010 © 2010 John Brewer, Jr. and Kamaljit Bagha ii Table of Contents Section Page Title Page i Table of Contents ii List of Table and Figures iv Acknowledgements vi I. INTRODUCTION 1 II. BACKGROUND 3 2.1 Predator® - Too Versatile For Its Own Good 3 III. REQUIREMENTS 5 IV. DESIGN 7 4.1 Inverter Project Design Overview 7 4.2 The Power Stage 10 4.3 The PWM Control Circuit and Signal Flow 17 4.4 The LC Output Filters 28 V. CONSTRUCTION 32 5.1 PWM Control Circuit Assembly 32 5.2 Inductor Construction 33 5.3 Wire Harnesses, Connectors, and Cable Fabrication 35 5.4 Power Plane Construction 36 5.5 Enclosure Fabrication 36 iii 5.6 System Assembly 37 VI. TESTING 38 VII. CONCLUSION AND RECOMMENDATIONS 45 VIII. BIBLIOGRAPHY 48 Appendices A. Schematic 50 B. Bill of Materials 66 C. Circuit Board Layout 69 D. Circuit Board IC and Component Locations 70 E. Hardware Configuration and Layout 71 iv List of Tables and Figures Table Page 3.1 MIL-STD-704F AC System Requirements [3] 5 3.2 Summary of Inverter Project Requirements 6 B.1 Bill of Materials and Donated Items 66 2.1 MQ-1 Predator Drone 3 2.2 MQ-9 Reaper Drone, originally named “Predator B” 4 4.1 IGBT Half-Bridge Configuration 7 4.2 Block Diagram of Inverter Project 9 4.3 Bootstrap Supply Topology with Protection 11 4.4 Nomenclature Used for IGBT Switching Transition 15 4.5 PWM Control Signal Flowchart 18 4.6 dsPIC-based Function Generator 19 4.7 Passive Component Nomenclature for UC3637… 21 4.8 Generating a Trigger Pulse 25 4.9 Bode Plot of Second Order LC Filter 28 5.1 Portion of Circuit Board Layout Graphic 32 5.2 Wire Wrapping 33 5.3 Inductor Bobbin 33 5.4 Tightly Wound Inductor 34 Figures v 5.5 Wood Handle to Support Bobbin 34 5.6 Finished Inductor with Connectors and Mylar Tape 34 5.7 Fabricated Wire Harnesses 35 5.8 Top and Bottom Sides of Copper-Clad Board 36 5.9 Inverter System Assembly 37 6.1 Ideal Inverter Pspice Simulation 38 6.2 Output Voltage Waveform of Ideal Inverter Simulation 39 6.3 IGBT Gate Driver and Half-Bridge Pspice Simulation 39 6.4 High-side (green) and low-side (blue) IGBT… 40 6.5 Adjustable Three-Phase Sinusoidal Reference… 42 6.6 Trigger Pulse successfully generated by AD823AN… 42 6.7 Square wave with 97% duty cycle successfully generated… 43 6.8 Three-phase and Neutral-phase Duty Cycle limited… 43 6.9 Three-phase Inverter Output Voltage referenced… 44 6.10 Three-phase Inverter Output Voltage referenced… 44 C.1 Microsoft PowerPoint Circuit Board Layout 69 D.1 IC and Component Circuit Board Location 70 E.1 Hardware Configuration and Layout 71 E.2 Test Bench Setup 72 Acknowledgements Acknowledgements We would like to thank – Mr. John (Jeff) Brewer, Director of Electrical Engineering for the Aircraft Systems Group at General Atomics Aeronautical Systems, Inc. for providing and funding a challenging project for us to work on and offering the technical support needed to complete this project. We appreciate him sharing his knowledge and insight of the broad range of topics that this project covers and have been inspired to work hard and never stop learning as electrical engineers. Dr. Taufik, Professor of Electrical Engineering at California Polytechnic State University, San Luis Obispo, as our faculty advisor for this project. His dedication and excellence as a teacher both in the classroom and lab have equipped us with a solid foundation of knowledge and understanding in the field of power electronics. His teaching curriculum and techniques significantly contributed to our ability to “Learn by Doing” here at Cal Poly. Mr. Jaime Carmo, Cal Poly EE Department Electronics Technician, for his support and generous donation of time, equipment, and parts throughout the construction, testing, and fabrication stages of our project. Mr. Cole Brooks, Cal Poly mechanical engineer and friend, for his assistance in metal parts fabrication Our families for supporting our educational endeavors. Sincerely, John Brewer, Jr. and Kamaljit Bagha 1 I. INTRODUCTION With the advent of the first power rectifier by an American engineer and applied physicist, Robert Hall, in 1952, a new form of power control and conversion was born – Power Electronics. The successive arrival of thyristors in 1957, bipolar transistors in the 1960s, power MOSFETs in the late 1970s, and IGBTs in the 1980s led to the rapid advancement of power electronics in all fields of electrical engineering [1]. These fields include utility power distribution, industrial electronics, and especially aircraft electronics because of the small size of power electronic components. A few applications of power electronics in these fields include power quality controllers, variable speed drives, and power supplies. Power electronics is unique in its method of power control and conversion in that it is based on the switching fully-on and fully-off of semiconductor devices to regulate power flow. More efficient than linear power regulation which uses variable resistance to regulate power flow, switching semiconductor devices by using a technique called “Pulse Width Modulation (PWM)” is the method used in a modern “switching” or “switched-mode” power supply (SMPS). PWM is a technique where the duty cycle of the semiconductor switch is manipulated to control power flow through the switch. As a result, the output voltage delivered to the load can be 2 well regulated to produce a fixed Direct Current (DC) voltage or a desired Alternating Current (AC) voltage. There are two types of converter topologies used in SMPS design – isolated and non-isolated. Transformers are used in the design of isolated converters to provide flexibility in circuit design by allowing for separate (isolated) input and output current return paths to “ground.” Non-isolated converters, however, do not use transformers and the input current ground is used as the ground for the output load current. For our application, we have designed a non-isolated SMPS that produces AC output voltage from DC input voltage – this is known as a DC/AC converter or, simply, an inverter. It uses the common method of Pulse Width Modulation to switch Insulated Gate Bipolar Transistors (IGBTs) to control the flow of power from ±DC input voltage “rails” to three-phase, sinusoidal AC output voltage. In the next section of this report, we will present the background and application of our inverter design. 3 II. BACKGROUND Our three-phase, sinusoidal inverter project was sponsored by Jeff Brewer, the Director of Electrical Engineering at General Atomics Aeronautical Systems, Inc. (GA-ASI). The purpose of this project was to design and build a proof-of-concept high-power switched-mode inverter. This project began the development process for a high-voltage three-phase AC power supply for use on any of the Predator® Unmanned Aircraft Systems (UAS) that GA-ASI manufactures. 2.1 Predator® – Too Versatile For Its Own Good Predator® aircraft like the ones shown in Figure 2.1 and Figure 2.2 are used by multiple branches of the United States’ military and homeland security including the Air Force, Army, U.S. Customs and Border Protection, Central Intelligence Agency, and NASA. They are popular for their wide range of applications including remote sensing, reconnaissance, weapons delivery, search and rescue, and surveillance. Predator® systems are versatile aircraft platforms upon which an increasingly large array of electronic device payloads like sensors, weapons, and communications equipment can be mounted. Fig. 2.1 – MQ-1 Predator Drone Source: Public Domain 4 Currently, these devices are powered by 28 VDC power on the aircraft – one of three standard aircraft power systems prescribed by MIL-STD-704F [3]. Because these aircraft are required to support an increasing number of electronic payloads, the weight of the cables in the aircraft needed to deliver 28 VDC power to these payloads exceeds practicality. So, to counteract this problem, plans to provide highvoltage power systems in accordance with MIL-STD-704F on Predator® aircraft are in effect. It is estimated that the cable weight required to distribute power on the aircraft will be reduced by a factor of ten when high-voltage power is provided [2]. These plans include the provision of a 270VDC system and a three-phase AC system as outlined in the next section of this report. Fig. 2.2 – MQ-9 Reaper Drone, originally named “Predator B” Source: Public Domain 5 III. REQUIRE REQUIREMENTS The purpose of our project was to design and build a non-isolated DC/AC SMPS capable of supplying 10 kW for a standard three-phase AC aircraft power system. According to MIL-STD-704F, “AC systems shall provide electrical power using single-phase or three-phase wire-connected grounded neutral systems. The voltage waveform shall be a sine wave with a nominal voltage of 115/200 volts [115 VRMS] and a nominal frequency of 400 Hz” [3]. Because MIL-STD-704F also prescribes AC system requirements like the sample shown in Table 3.1, the production level version of our inverter will require the use of closed-loop feedback to provide adequate line and load regulation. However, designing a closed-loop system was beyond the scope of this project, so an open-loop system was required. Table 3.1 – MIL-STD-704F AC System Requirements [3] Characteristics Steady State Voltage: Limits 108.0 VRMS to 118.0 VRMS Voltage Unbalance: 3.0 VRMS (maximum) Voltage Modulation: 2.5 VRMS (maximum) DC Component: Voltage Phase Difference: Steady State Frequency: Frequency Modulation: Peak Voltage: +0.1 to -0.1 Volts 116° to 124° 393 Hz to 407 Hz 4 Hz ±271.8 Volts 6 Lastly, the production level version of our inverter will be powered by the engine alternator on the aircraft. The three-phase, variable voltage, variable frequency engine alternator power will be rectified and regulated to produce ±190 VDC rails from which the inverter will draw its power [2]. Since this rectification and regulation of engine alternator power is beyond the scope of this project, it was required that our proof-of-concept inverter work from ±125 VDC rails for three-phase operation given 10Ω resistive loads. This requirement was limited by the available test equipment in Cal Poly’s EE Department Power Electronics Lab. The nominal requirements of our inverter project are summarized below in Table 3.2. In the following section of this report, we will present a system overview of our inverter project followed by a more detailed discussion of the circuit design process. Table 3.2 – Summary of Inverter Project Requirements Nominal System Requirements Converter Topology: Input Voltage: Output Voltage: Output Voltage Waveform: Non-Isolated SMPS ±125 VDC 85 VRMS AC Three-Phase, Sinusoidal Steady State Frequency: 400 Hz Maximum Output Power: 10 kW 7 IV. DESIGN This section of our report represents a majority of the work that went into this project – circuit design. In this section, we will present an overview of our inverter project followed by a series of discussions covering the details of the circuit design, signal flow, and discrete components used. 4.1 Inverter Project Design Overview The design of our three-phase sinusoidal inverter is based on the PWM switching of N-Channel IGBTs connected in a half-bridge configuration as shown in Figure 4.1. As the high-side and low-side IGBTs are complementarily switched fullyon and fully-off, they connect the load to the +DC and -DC Rails, respectively. Since the output is connected to one of two voltage polarities during this method of switching, it is known as Bipolar Switching. Because the output voltage is effectively an amplified version of the PWM Control Input, this stage of the inverter system can be considered the Fig. 4.1 – IGBT Half-Bridge Configuration Source: John Brewer, Jr. Power Amplification stage and is shown in the System Block Diagram in Figure 4.2. 8 The IGBT Gate Drivers and Floating Bootstrap Supply topology required to drive N-Channel IGBTs in this configuration are also indicated in Figure 4.2 and will be discussed in Section 4.2.1. The PWM Control Input is generated by the PWM Control Circuit block. The PWM Control Circuitry is responsible for generating the sinusoidal reference waveforms, establishing the switching frequency, creating PWM signals, limiting the duty cycle of the PWM signals, and interfacing logic-levels. A thorough discussion of the PWM Control Circuitry will be presented in Section 4.2.2 of this report. The final piece of our inverter design is the inductor/capacitor (LC) output filters on each phase. The LC output filters were designed to smooth the PWM output of the Power stage and filter out high-frequency harmonics introduced by IGBT switching. These will be discussed in Section 4.2.3. An important characteristic to note about our inverter design is the fourth IGBT Half-Bridge “leg” which is used to create a virtual ground (neutral) through which phase currents from an unbalanced three-phase load can return to the DC input supply. The PWM Control Input to this neutral leg will have a nominal 50% duty cycle, creating a voltage that is one-half the DC supply voltage upon which the three-phase sinusoidal output voltages will be centered. The creation of this neutral return is necessary in the case that a bipolar DC supply with ground connection is unavailable and a unipolar DC supply must be used. Fig. 4.2 – Block Diagram of Inverter Project Source: John Brewer, Jr. and Kamaljit Bagha 9 10 4.2 The Power Stage As mentioned in Section 4.1, the Power Stage consists of two IGBTs connected in a Half-Bridge configuration. Four identical half-bridge legs form the foundation of our three-phase inverter and are responsible for controlling power flow from the DC Input Supply to each phase output voltage – Phase A, Phase B, Phase C, and Neutral. Jeff Brewer donated the IGBTs that were to be used for this project – IRGP50B60PD1, WARP2 Series IGBT with Ultrafast Soft Recovery Diode from International Rectifier (IR). These IGBTs are high-speed, high-power, SMPS, N-Channel IGBTs capable of withstanding a collector-to-emitter voltage of 600V. Driven with a gate-to-emitter voltage of 15V, these IGBTs can source 33A with maximum turn-on and turn-off delay times of 40ns and 150ns, respectively [4]. With an operational output voltage of 115VRMS, the resulting power output capability of all three inverter phases combined can then be calculated to be: = 3 ∗ ∗ (Eq. 4-1) ∴ = 3 ∗ 33 ∗ 115 = 11.385 In conclusion, using these IGBTs will fulfill our requirement to design a threephase inverter capable of supplying 10kW with an output voltage of 115VRMS. In the next section, we will discuss the floating bootstrap supply topology required for 11 switching N-Channel devices, the IGBT Gate Driver design process, and design measures taken to protect the IGBTs. 4.2.1 Bootstrapping, IGBT Gate Drivers, and Transient Voltage Protection N-Channel semiconductor devices are commonly used in half-bridge configurations as our IGBTs are used in the power stage of our inverter. However, these N-channel devices require a charge applied to the gate that is positive with respect to the emitter such that (VGE > VTH). While this does not present a problem for turning on low-side devices with a power supply referenced to the –DC rail, the same supply would be unable to turn on the corresponding high-side device as the high-side emitter follows the output voltage of the half-bridge – a much larger voltage than the supply voltage. Therefore, a bootstrap supply topology is required. As illustrated by the schematic of a typical bootstrap supply topology in Figure 4.3, a bootstrap capacitor is connected from the power supply, VCC, to the high-side emitter. Due to the charge storage characteristics of a capacitor, the bootstrap capacitor voltage will rise +VCC above the high-side emitter, providing the Fig. 4.3 – Bootstrap Supply Topology with Protection Source: John Brewer, Jr. 12 necessary gate drive voltage to turn on the high-side device. When an internal switch in the Gate Driver Integrated Circuit (IC) connects node VB to the high-side gate, the high-side device will turn on. It will then turn off when the gate is disconnected from VB and connected to VS by internal switches in the Gate Driver IC. However, the high-side device will also turn off if the charge on the bootstrap capacitor is depleted due to parasitic gate current. Because of this, the duty cycle of the high-side device switching must be limited and the bootstrap capacitor sized accordingly to prevent premature/uncontrolled turn-off of the high-side device. For our project, we decided to use the Si8234BB ISOdriver manufactured by Silicon Labs as our High-Voltage Integrated Circuit (HVIC) Gate Driver. This recently released HVIC Gate Driver contains two completely isolated high-side/low-side drivers in one package that are each capable of sourcing 4.0A peak output current. The isolated drivers are controlled by a single PWM Control Input signal and an external resistor used to program the deadtime created between the switching of the high-side and low-side devices. The input logic side of the device is 5V TTL compatible, while the output side can support the 15V supply used to switch our IGBTs. Also note that we have incorporated the Disable pin of the Si8234BB device into our circuit design to provide the functionality of being able to turn combinations of our phase output voltages on or off [5]. We consulted IR’s “Design Tips for Using Monolithic High Voltage Gate Drivers” during the design process for our HVIC gate drivers and floating bootstrap 13 supply [6]. To size the bootstrap capacitor, we started by calculating the maximum voltage that the bootstrap capacitor voltage was allowed to drop (∆VBS) when the high-side IGBT was supposed to be on. To do this, we decided from Fig. 8 of our IGBT datasheet that the minimum gate-to-emitter voltage to allow should be 11V in order to guarantee a collector-to-emitter voltage of about 2V given a collector-toemitter current around 33A. Also, we used a value of 1V for the typical forward voltage drop of the MUR460 power rectifier used to protect VCC as shown in Figure 4.3 [7]. As a result, we obtain ∆ = − − , − , (Eq. 4-2) ∴ ∆ = 15 − 1 − 11 − 2 ≅ 1 We then confirm that VGE,min > VBSUV- where VBSUV- is the high-side supply undervoltage negative going threshold of 8.10V as indicated in Table 1 of the “Si823x” datasheet from Silicon Labs [5]. The next step in sizing the bootstrap capacitor was to consider the following factors contributing to a decrease in VBS: - IGBT turn-on required Gate charge (QG) = 308nC (max) [4] - IGBT Gate-Emitter leakage current (IGES) = 100nA [4] - Output supply quiescent current (IDDAQ) = 3.0mA (max) [5] - Bootstrap diode instantaneous reverse current (ILK_D) = 50μA [7] - Bootstrap capacitor leakage current (ILK_C) = - High-side on time (TH,on) = 24.5μs 0μA (use ceramic capacitors) (98% duty cycle at 40kHz) 14 Then we have #$% = # + ' + (() + %*_, + %*_ - ∗ ./, (Eq. 4-3) ∴ #$% = 30812 + 31001 + 3.04 + 505 + 056 ∗ 24.558 ≅ 38312 And the minimum size of the bootstrap capacitor can be calculated by 2, = )9:9;< (Eq. 4-4) ∆=>? ∴ 2, = @A@ B= ≅ 3831C So, to account for estimation error and temperature drift, we decided to use a bootstrap capacitance of 660nF, almost twice as big as the calculated CBOOT,min. As mentioned earlier, MUR460 power rectifiers are an ideal choice for use as the bootstrap diode in our bootstrap supply design. These devices were also donated to our project and can withstand a reverse voltage of 600V and have a reverse recovery time of less than 100ns [7]. The final design issues to be mentioned regarding the design of the IGBT gate drivers are the addition of decoupling capacitors, sizing of gate resistances, and measures taken for protecting the IGBTs and HVIC Gate Drivers. Sufficient decoupling capacitance was added to our gate driver design by placing ceramic and electrolytic capacitors in parallel with the gate drive supply voltage very close to both the low-side Gate Driver output pins and the bootstrap diode. The ceramic capacitor provides a fast charge tank and limits DF DE by reducing the equivalent series resistance while the electrolytic provides a longer lasting charge tank. 15 The process for sizing the gate resistances consisted of both calculations to derive ballpark figures and hardware experimentation. From “Design Tips for Using Monolithic High Voltage Gate Drivers,” we can estimate the necessary size of the turn-on gate resistor by fixing the switching-time. As shown in Figure 4.4, the switching time is defined as the time spent to reach the end of the plateau voltage resulting from charging the IGBT gate capacitances with QGC and QGE. Estimating Fig. 4.4 – Nomenclature Used for IGBT Switching Transition Source: International Rectifier [6] an appropriate switching time to be about 115ns and knowing QGC and QGE to be 105nC and 45nC, respectively, we can calculate $=$ = )GH I)GJ ∴ $=$ = (Eq. 4-5) KLM BNOIPO BBOQ ≅ 1.3 And R$% =HH T =UV (Eq. 4-6) W;XJY;GJ where Vge* is approximated to be 6.2V from Fig. 17 of our IGBT datasheet [4], and R$% RZ3Q [\]^6 & R, (Eq. 4-7) 16 Where RON(source) is 2.7Ω according to the Si8234BB datasheet, and RG,on is the value for the high-side IGBT gate resistor [5]. As a result, we have R, = BO=T_.`= B.@$ − 2.7Ω ≅ 4Ω And following IR’s Design Tip, we size the low-side IGBT gate resistor to be larger than the gate resistor of the high-side device – about 5Ω. This will result in softer switching of the low-side device and a reduction in magnitude of the voltage transients caused by parasitic inductances during switching. Lastly, the design of the Power stage includes devices added to protect IGBTs and HVIC Gate Drivers from transient voltage spikes caused by parasitic inductances in the circuit. First, Zener clamp diodes with a reverse voltage breakdown voltage of 16V are added across the gate-to-emitter junctions of both high-side and low-side devices. Shown in Figure 4.3, these Zener clamps protect the HVIC Gate Driver output, sink current generated by transient voltage spikes occurring on the collector, and keep the IGBT gate-to-emitter voltage from exceeding the maximum limit of 20V [4]. Another clamp device used is the series combination of a 16V Zener diode and MUR460 Power Rectifier positioned between the VS pin of the HVIC Gate Driver and the –DC rail also shown in Figure 4.3. The purpose of this clamp device is to guarantee that VS does not exceed maximum undervoltage limits when negative voltage transient spikes are induced by parasitic inductances. The production level version of our inverter will include the placement of reverse-biased transient voltage 17 suppression diodes with a reverse breakdown voltage <600V across the collector-toemitter IGBT terminals. These will protect the IGBTs from damage caused by voltage transients on the DC supply rails or half-bridge output node. Due to the DC input supply test limits, we omitted these diodes from our proof-of-concept design. The circuit schematics for the four Power Stages of our inverter design can be found on Sheets 11, 12, 13, and 14 of the system schematic in the Appendices. In the next section of this report, we will discuss the PWM Control Circuit and signal flow. 4.3 The PWM Control Circuit and Signal Flow The PWM Control Circuit is the “brain” of our inverter project and is responsible for generating our three-phase sinusoidal reference signals, producing PWM Control signals for all three-phases and neutral, limiting the duty cycle of the PWM Control signals, and interfacing logic levels. It was designed using discrete analog components with the exception of a Microchip dsPIC 16-bit Digital Signal Controller-based function generator. Considerations for choosing the discrete analog devices we used included availability, ease of prototype implementation, proven reliability, low replacement cost, and extreme temperature tolerance for military temperature requirements. 18 In this section of the report, we will present a discussion of the circuit components used to perform these tasks and cover the details of the circuit design required to interface these components and generate PWM Control Input signals for the HVIC Gate Driver of each IGBT half-bridge. Figure 4.5 illustrates the general flow of a single phase PWM Control signal. Fig. 4.5 – PWM Control Signal Flowchart Source: John Brewer, Jr. 19 4.3.1 Generating Three-Phase Sinusoidal Reference Signals The first step in the design of the PWM Control Circuit was to generate three sinusoidal reference voltages, each having 120° of phase displacement from the others. Fortunately, this step was already complete before we began our project. Manufactured and donated by GA-ASI, the Microchip dsPIC Digital Signal ControllerBased Function Generator shown in Figure 4.6 supplies three-phase sinusoidal waveforms with accurate sine shape and phase displacement. The frequency and amplitude of the output sinusoids are adjustable, but for our application they are set to have a frequency of 400 Hz and peak-topeak amplitude of 2V. In order to make the amplitude of our inverter output Fig. 4.6 – dsPIC-based Function Generator voltage waveforms adjustable, Source: John Brewer, Jr. remove the DC offset from the reference sinusoids, and buffer the reference sinusoids, we AC coupled each of the sinusoidal phase voltages from the function generator to adjustable gain, non-inverting amplifiers designed using TL082 JFET Input Op-Amps. Simple RC highpass filters with a cutoff frequency of 1 Hz were used for the AC coupling. The TL082 op-amps were chosen because of their suitable slew rate of 13V/μs, low Total Harmonic Distortion of 0.003%, ability to operate from 20 ±15V supplies, and compact 8-pin packages containing two op-amps each. The circuit schematic for this step in the PWM Control Circuit can be located on Sheet 3 of the system schematic in the Appendices. 4.3.2 Generating PWM Signals from Reference Sinusoids The next step in the design of the PWM Control Circuit was to generate the PWM Control signals for each phase including neutral by comparing the reference sinusoids to a triangle wave having a frequency equal to the desired IGBT switching frequency. Using a PWM Controller IC is the most efficient way to do this, so we chose the Unitrode UC3637 Switched-Mode PWM Controller for DC Motor Drives. The UC3637 was chosen because of its high reliability, robustness, and widespread use in industry. It is easy to program and provides a built in error amplifier, under-voltage lockout, and can operate from dual power supplies [8]. Concurrently, multiple UC3637 ICs can be readily synchronized according to Unitrode’s Design Note about “Design Considerations for Synchronizing Multiple UC3637 PWMs” [9]. This was an important quality of the UC3637 since four PWM Controller ICs were required in the PWM Control Circuit and the ability to synchronize them would simplify circuit construction. We arbitrarily decided to establish the Neutral phase PWM Controller as the Master PWM device. This IC was “programmed” with the passive components shown in Figure 4.7 according to the following design requirements: 21 • Triangle Wave frequency of 40kHz (same as the IGBT switching frequency). • Triangle wave amplitude of 20 VP-P (large to increase noise immunity). • Modulation scheme with no deadtime (since the Si8234BB IGBT Gate Driver supplies the necessary high-side/low-side switching deadtime). • Under-voltage lockout level of 10.75V (to prevent switching IGBTs when there is not enough supply voltage to fully turn them on). Fig. 4.7 – Passive Component Nomenclature for UC3637 Master Device Programming Source: John Brewer, Jr. Consulting the Unitrode UC3637 Datasheet and following the Unitrode Application Note U-102, we calculated the following [8] [10]: R 3I=9c 6T3T=? 6 ∴ R (4-8) W? 3IBN =6T3T BO =6 N.O$ = 50Ω ≅ 47.5Ω 22 2 W? `de3I=9c 6T3T=9c 6f (4-9) N.O$ ∴ 2 `∗PNg/h∗e3IBN =6T3TBN =6f = 313iC ≅ 300 iC For clarity, we note that the Unitrode Application Note U-102 suggests that the constant current used to charge the external capacitor, CT, be within the range of 0.3 to 0.5 mA. Because the amplitude of the triangle wave has been designed fairly large, we programmed ISET to a value on the higher end of this range, 0.5 mA, as used in Eq. 4-9. Using this higher charging current performs a secondary feature of allowing the use of a larger capacitor, CT, that will be able to store enough charge to drive the input of a TL082 op-amp configured as a voltage-follower. This will produce a buffered triangle wave used to drive the UC3637 slave devices and the AD823AN op-amp used for generating a trigger pulse for the HCF4538B Monostable Multivibrator Since +VTH and -VTH should be symmetrical at ±10V in our application, we set R1 = R5 and calculate REQ (where REQ = R2 + R3 + R4) after choosing reasonable values for R1 and R5. Using an iterative process to determine values for R1 and R5, we • Calculated REQ • Calculated the approximate bias current, IBIAS, through the resistor divider created by R1, REQ, and R5 between +VS and -VS. • Adjusted values accordingly to limit the bias current to an order of hundreds of microamps. This prevented unnecessary power loss while 23 maintaining the ability to adequately charge the PWM controller comparator inputs. As a result, RB RO 20.4Ω R) = ` ∗ j ∗ =9c (4-10) =? T =9c ∴ R) = ` ∗ `N,PNNk ∗ BN= BO= T BN= = 81,600 Ω We also needed to ensure that the +VSLV node voltage indicated in Figure 4.7 was always less than the magnitude of the triangle wave despite any drift in resistance, the UC3637 Master PWM device characteristics, or the AD823AN op-amp characteristics. This will guarantee the generation of a trigger signal for the HCF4538B Monostable Multivibrator which is used to create a square wave with frequency equal to the triangle wave and duty cycle of 98%. In order to do this, we needed to determine the minimum voltage difference, ∆Vmin, required between +VTH and +VSLV. Following the procedure outlined in Unitrode Design Note DN-53A, we determined ∆Vmin to be about 1.5V, requiring a ballpark resistance for R2 and R4 to be 6.3kΩ [9]. However, based upon the hardware available during the construction phase of our project, R` = RP = 5.62Ω and R@ = 68.1Ω Yielding W$ = I=? T3T=? 6 m In Ij Io Ip (4-11) 24 IBO= T 3TBO=6 ∴ W$ `N,PNNk I O,_`Nk I _A,BNNk I O,_`Nk I `N,PNNk ≅ 2505 Lastly, we used the equation provided in the UC3637 IC datasheet to establish an undervoltage lockout level of 10.75V. Using a 100kΩ resistor for R6, we calculated $ = ∴ Rs = =?9;Y9 ∗ q `.O − R_ = `.O∗3q Ir 6 q BN.sO=∗BNNgk `.O (4-12) − 100Ω = 330Ω At this point, the simplicity of synchronizing the other three UC3637 slave devices becomes evident. Besides adding 0.1μF decoupling capacitors to all device pins that are tied to a fixed voltage, we simply connect the +VSLV node to the +VTH slave device pins, the –VSLV node to the –VTH slave device pins, the SD pin of the master device to the SD pins of the slave devices, and the buffered triangle wave output from the TL082 voltage-follower to pins 2, 8, and 10 of the slave PWM devices. The -15V low/+15V high PWM Control Input signals are each interfaced with their respective 74AC00 CMOS NAND Gates by a current limiting resistor/voltage divider/Schottky diode network that reduces the signal to 0.4V low/+5V high. In the next sections of this report, we will discuss the portions of the PWM Control Circuit that limits the duty cycle of the PWM Control Inputs to 98%. 25 4.3.3 Generating a Trigger Pulse As mentioned in the previous section, our PWM Control Circuit design includes the use of an AD823AN rail-to-rail FET Input op-amp as a comparator. According to the AD823AN datasheet, this op-amp has a high slew rate of 22V/μs and can operate from ±15V supplies [11]. As a result, this op-amp provides the speed needed for a short switching transition time and required no voltage level shifting to interface the ±20V buffered triangle wave. Although the AD823AN is a dual op-amp package, only one of the op-amps is needed by our control circuit. With the buffered triangle wave tied to the positive input and the +VSLV voltage tied to the negative input of the comparator, a +15V pulse with duration of about 1μs is generated when the triangle wave is at its peak and exceeds the +VSLV threshold as illustrated in Figure 4.8. This -15V low/+15V high trigger pulse is interfaced with the HCF4538B Monostable Multivibrator through a current limiting resistor and Schottky diode network that reduce the trigger Fig. 4.8 – Generating a Trigger Pulse pulse to a 0.4V low / +15V high pulse. Source: John Brewer, Jr. 4.3.4 Monostable Multivibrator After being triggered by the trigger pulse delivered by the AD823AN comparator, the HCF4538B Monostable Multivibrator configured as a non- 26 retriggerable one-shot generates a 24.5μs pulse. Since the trigger pulse is delivered every 25μs, the equivalent waveform produced is a 40kHz square wave with a duty cycle of 98%. This 0V low/15V high signal is interfaced with the 74AC00 CMOS NAND Gates through a simple resistor divider reducing it to a 0V low/+5V high signal. The timing equations and wiring configuration for a non-retriggerable oneshot design were given by the HCF4538B datasheet [12]. As illustrated in our schematic (See Appendix) we paired a 5,600pF timing capacitor, C38, with a 10kΩ potentiometer, R22, so we could adjust the output pulse of width, T, according to the equation . R`` 2@A (4-13) `P.OuQ ∴ R`` O,_NNv = 4.375Ω jt 4.3.5 High-speed CMOS NAND Gates The 74AC00 CMOS NAND Gates used in our PWM Control Circuit provide the logical AND function needed to limit the duty cycle of the PWM Control Input signals to 98% [13]. By “ANDing” the PWM Control input signal for each phase of our inverter with the square wave output by the One-Shot, the duty cycle of the PWM Control Input signals are effectively limited to 98%. This provides the high-side IGBT off-time necessary for recharging the bootstrap capacitor as discussed in Section 4.2.1. 27 4.3.6 Supplying Power to the PWM Control Circuit and Bootstrap Supply After having figured out how to drive our inverter IGBTs and design the PWM Control Circuit, we needed to figure out how to supply power to the low-voltage side of our project. Since the function generator donated to our project by GA-ASI came with its own power supply, we only needed to supply +15 VDC, -15 VDC, and +5 VDC to our circuit. For these voltages, we bought two 15V and one 5V isolated AC/DC wall adapters – the first two sold as “Notebook Adapters” and the latter as an “Internet Router Adapter.” Since these adapters are isolated, we were able to reference our PWM Control Circuit DC Bias Supply voltages to the most negative voltage used for the DC Input Supply to our inverter – a requirement for properly driving our Half-Bridge IGBT topology with a Bootstrap Supply. 4.3.7 Using Decoupling Capacitors As we complete our discussion of the PWM Control Circuit, it is important to note the use of decoupling capacitors throughout our circuit design. The use of 0.1μF ceramic capacitors tied between logic ground and any IC pin connected to a bias voltage provides sufficient AC decoupling and noise immunity. It is also important to note the use of sufficiently larg electrolytic bias supply capacitors located at the circuit board D-sub connector where the power is delivered to the board. 28 4.4 The LC Output Filters The design process for our inverter project included the design of three Second-Order LC filters to be used for smoothing the output voltage waveforms for each phase of our inverter. The design of these LC output filters was based on the 400Hz output voltage frequency and the 40kHz PWM switching frequency. As illustrated by the Bode plot in Figure 4.9, we designed the LC output filter to have a corner frequency of 2kHz so it would effectively pass the 400Hz voltage waveform while sufficiently attenuating the 40kHz PWM switching frequencies. We also designed the LC filter to have a low output impedance of 2Ω. Fig. 4.9 – Bode Plot of Second Order LC Filter Source: John Brewer, Jr. Therefore, using L = 159μH and C = 40μF, w B (4-14) `x√% ∴w B `xzBO{u/PNu 1,995}~ " 2}~ 29 And, % (4-15) BO{u/ ∴ PNu 1.99Ω ≅ 2Ω 4.4.1 Inductor Design During the design process of the inductors for our inverter, we received some much needed help from Jeff Brewer [2]. The most significant factor in the inductor design process was the desired inductance and maximum amount of current that would flow through an inductor during inverter operation. Although the nominal output current of each inverter phase is 33A, we designed the inductors for our inverter to be able to carry up to 50A. Based on the equation for energy stored in an inductor, we needed to design inductors that could each store B % = ` (4-16) ` ∴ QK \^ B = ∗ 1595} ∗ 3506` = 0.19875 8 ` Then using = `∗LV ∗BNo ∴ = where AP = area product in cm4. (4-17) ∗* ∗* `∗N.B{AsO∗BNo ONNN∗P_A∗N.O = 34.2 4P 30 Kj = the current density coefficient for a given core and a given temperature rise. Ku = the cross sectional area of copper to the total window area or packing factor. Bmax = the maximum flux density in Gauss. from selecting an AMCC-50, size 10, PowerLite C-Core [2] [14] [15]. These PowerLite cut C-cores are made out of Metglas iron alloy material and will not only make our inductors easy to fabricate but also allow for fine tuning of inductance by adjusting the air gap and using an Impedance Bridge To determine the minimum number of turns, Nmin, and the length of air gap, Lgap, needed in each leg of the cut C-core inductor, we used %WH, ∗BNt (4-18) ∗$U ∴ = BO{u/∗ON$∗BNt O,NNN∗@.`]n = 49 E18 where L= Inductance of the inductor in microHenries. IDC,max = Maximum current through the inductor in Amps. Agap = Total cross sectional area of the air gap including fringing. And v = .`∗x∗$U ∗BNn ∗Zn ∴ v = % .`∗x∗@.`]n ∗BNn ∗P{n BO{u/ (4-19) = 0.304 1ℎ8. 31 Lastly, we determined that although making an inductor by wrapping insulated Copper Foil around a Ferrite Core would result in lower core losses for the beneficial design tradeoff of higher copper loss, it would be hard to fabricate for a prototype. So, we chose 10AWG magnet wire with a heavy insulation build for withstanding temperatures up to 200°C to wrap our AMCC-50 cores with [16]. We were able to successfully wrap our inductor bobbins with 49 turns and connect two bobbins in parallel, one on each inductor leg, for a generous inductor current capacity of 50A. In the next section of this report, we will discuss the construction phase of our inverter project. 32 V. CONSTRUCTION The construction and assembly phase of our proof-of-concept inverter project consisted of six main parts – PWM Control Circuit assembly, Inductor construction, Wire Harnesses, Connectors, and Cable fabrication, Power Plane construction, Enclosure fabrication, and System assembly. 5.1 PWM Control Circuit Assembly Before starting construction of the PWM Control Circuit, we used Windows Paint to create scale drawings of our perforated circuit board (PerfBoard), components, and ICs. We then copied these scale drawings into Microsoft PowerPoint where we were then able to freely move, place, label, and “wire” components according to our circuit design. Figure 5.1 shows a part of our Circuit Board Layout. To make connections on our circuit board, we used a combination Fig. 5.1 – Portion of Circuit Board Layout Graphic of soldering and wire wrapping; Source: John Brewer, Jr. however, soldering was only used to solder short connections like decoupling capacitors to IC pins while wire wrapping constitutes a majority of our connections. 33 A common prototype technique, wire wrapping uses a wire wrap tool to tightly wrap 30AWG Kynar wire around special wire wrap “posts.” Using two PerfBoards, one on top of the other, provides a much stronger circuit board to work with and helps keep wire wrap posts straight. Figure 5.2 illustrates this technique. For our proof-of-concept prototype, the design and fabrication of a Printed Circuit Board (PCB) would not have been cost effective and would have made circuit Fig. 5.2 – Wire Wrapping Source: John Brewer, Jr. modifications difficult. 5.2 Inductor Construction To construct the inductors, we needed to wrap 10AWG enameled wire 49 times around the inductor bobbins shown in Figure 5.3. As shown in Figure 5.4, we needed to guarantee that the wire was wrapped very tightly around each bobbin so that two bobbins would fit on one core. In order to prevent cracking a bobbin during the wrapping process, Jeff Brewer fabricated the wood handle shown in Figure 5.5 to fit snugly inside each bobbin as it was wound. Fig. 5.3 – Inductor Bobbin Source: John Brewer, Jr. 34 When it was time to put two wire-wrapped bobbins on a core, we used the right-hand-rule to determine the orientation of the bobbins on the core to guarantee that the flux induced by the coiled wire on each bobbin was flowing through Fig. 5.4 – Tightly Wound Inductor the core in the same direction. Using an Source: John Brewer, Jr. Impedance Bridge, we adjusted the air gap of each inductor to obtain our desired inductance at 2kHz – 159μH. We then used small squares of PerfBoard as spacers inside the bobbins between the core halves to maintain the necessary air gap of each inductor. Fig. 5.5 – Wood Handle to Support Bobbin Using a sharp edge, Source: John Brewer, Jr. we scraped about an inch of enamel coating from each end of the wires to be connected. Lastly, we crimped and soldered them to a connector and wrapped up the inductor using hightemperature Mylar tape as shown in Figure 5.6. Fig. 5.6 – Finished Inductor with Connectors and Mylar Tape Source: John Brewer, Jr. 35 5.3 Wire Harnesses, Connectors, and Cable Fabrication In order to simplify the assembly, transportation, testing, and modification process, we designed and fabricated the following wire harnesses, connectors, and cables: • For signals and voltages delivered to our circuit board from the function generator and low-voltage bias power supply jacks, we wired, soldered, and applied heat-shrink to the 15-pin D-sub connector shown in Figure 5.7. • To connect to the function generator 8-pin inline header output pins, we used the mating female crimp contact receptacle also shown in Figure 5.7. • To connect to the output enable switch voltages from the front panel of our enclosure, we used a 10-pin inline header with mating crimp contact receptacle also shown in Figure 5.7. • To connect the DC Input Voltages to our Input Capacitors and Power Planes, we used Fig. 5.7 – Fabricated Wire Harnesses three parallel lines of Source: John Brewer, Jr. stranded 10AWG wire with crimp/ring connectors. 36 • To connect output voltage nodes from the copper-clad circuit board to the inductors and the LC output filters to the enclosure panel, we used stranded 10AWG wire with crimp/ring connectors. These ring connectors in conjunction with nuts, bolts, washers, and lock washers made it quick to assemble and disassemble our prototype for modifications. 5.4 Power Plane Construction In order to effectively reduce parasitic inductances in the DC Input Voltage supply path, we used double-sided copper-clad board for the ±input voltage delivered to the IGBTs. We used a combination of precise cutting and drilling to create isolated copper pads with at least a 3:1 ratio of length to width for current flow. A section of both the top and bottom power planes are shown in Figure 5.8. 5.5 Enclosure Fabrication For ease of transportation, Fig. 5.8 – Top and Bottom Sides of Copper-Clad Board setup, and testing of our inverter Source: John Brewer, Jr. prototype, Jaime Carmo generously donated his time and materials to fabricate a Plexiglas enclosure for us. This enclosure allowed us to effectively and efficiently mount all of our system components and display our project for exhibition. 37 5.6 System Assembly System assembly consisted of placing and arranging system components, drilling mounting holes in the Plexiglas enclosure, and fastening components together or to the enclosure with wire ties, circuit board standoffs, nuts, bolts, washers, and lock washers. Our final System Assembly is shown in Figure 5.9. Fig. 5.9 – Inverter System Assembly Source: John Brewer, Jr. 38 VI. TESTING For our project, we performed several stages of testing – Ideal Inverter Pspice simulation, IGBT Gate Driver and Half-Bridge Pspice simulation, PWM Control Circuit hardware testing, PWM Control Circuit and single IGBT Half-Bridge hardware low power testing, and full system testing. For the Ideal Inverter Pspice simulation, we simulated an open-loop switched-mode single phase PWM inverter circuit with Neutral phase using ideal components as shown in Figure 6.1 to obtain the output sinusoidal waveform shown in Figure 6.2. Fig. 6.1 – Ideal Inverter Pspice Simulation Source: John Brewer, Jr. 39 120V 80V 40V -0V -40V -80V -120V 45.0ms 45.5ms V(R_LOAD:1)- V(R_LOAD:2) 46.0ms 46.5ms 47.0ms 47.5ms 48.0ms 48.5ms 49.0ms 49.5ms 50.0ms Time Fig. 6.2 – Output Voltage Waveform of Ideal Inverter Simulation Source: John Brewer, Jr. For the IGBT Gate Driver and Half-Bridge Pspice simulation shown in Figure 6.3, we simulated an IR2113 Gate Driver and IRGP50B60PD1 Half-Bridge driven with a 40kHz, 50% duty cycle square wave with 1μs of deadtime programmed in between high-side and low-side switching. Despite not being able to use the Si8234BB IGBT gate driver in our simulation, we were still able to analyze the bootstrap power supply topology used to turn the high-side IGBT on. The gate-to- Fig. 6.3 – IGBT Gate Driver and Half-Bridge Pspice Simulation Source: John Brewer, Jr. 40 emitter voltage waveforms 40A and output current waveform 20A are shown in Figure 6.4. We tried to limit the 0A -20A I(Rload) 20V time spent developing and 10V analyzing the Pspice 0V simulations for our inverter project because it was difficult SEL>> -10V 0s 5us V(U2:2)- V(U2:3) 10us V(U3:2)- V(U3:3) 15us 20us 25us to accurately model all of the Fig. 6.4 – High-side (green) and low-side (blue) IGBT gate-to-emitter voltage waveforms. Load current waveform (top). parasitic elements that would Source: John Brewer, Jr. 30us affect the high-power performance of our hardware design in the end. Concurrently, our detail-oriented approach to the design of the PWM Control Circuit and the thorough analysis of the aforementioned design tips and application notes published by International Rectifier and Silicon Labs regarding HVIC Gate Drivers and the bootstrap supply topology warranted immediate prototyping and hardware testing. As a result, we constructed a prototype of our PWM Control Circuit design, tested it, and observed successful results. Because we implemented resistance trimmers at critical points in the circuit, we were able to fully tune the prototype design. Next, we constructed a low-power single phase prototype of the IGBT Gate Driver with bootstrap supply and Half-Bridge topology. At this point in the testing, 41 we encountered problems regarding bias supply ground referencing, low-side decoupling capacitor sizing, and gate resistance sizing which caused us to take a closer look at IR’s design notes and modify our circuit design. After doing so, our testing yielded successful results for low-power switching of our IGBTs using ±39VDC input supply and less than 1A output current. After completing assembly of the final version of our proof-of-concept threephase inverter design, we performed full system tests. Due to a miscommunication during a discussion about the DC Power available for testing in Cal Poly’s EE labs, we were only able to test all three-phases of our inverter with a ±DC input supply voltage of ±48V due to test equipment voltage and current limits. However, these tests were all successful. After powering-up the PWM Control Circuit with the inverter outputs disabled, we turned on each phase and gradually increased the ±DC input supply voltage while monitoring all node voltages on the high-voltage side of our circuit – IGBT Gate Driver pin voltages, IGBT gate, collector, and emitter voltages, supply voltages, and output voltage. After reaching test equipment current limits, we reported the following about Figure 6.5 through Figure 6.10: 42 Fig. 6.5 – Adjustable Three-Phase Three Sinusoidal Reference signals successfully generated, UC3637 38kHz Triangle Wave successfully generated and compared with with Sinusoidal Reference signals to produce three three-phase PWM Control Input signals. Fig. 6.6 – Trigger ger Pulse successfully generated by AD823AN Op-Amp Op Amp Comparator. 43 Fig. 6.7 – Square wave with 97% duty cycle successfully generated by Trigger Pulse and HCF4538B One-Shot. Fig. 6.8 – Three-phase phase and Neutral-phase Neutral Duty Cycle limited PWM Control Input signals sign successfully generated. 44 Fig. 6.9 –Three-phase phase Inverter Output Voltage referenced to supply ground with ±48VDC Input Voltage. Output voltage is 87 VP-P, 61 VRMS. Output RMS current is 6.2 A. Input RMS current is supply limit of 6.5 A. Fig. 6.10 –Three-phase phase Inverter Output Voltage referenced reference to virtual ground with ±46VDC Input Voltage. Output voltage is 86 VP-P, 61 VRMS. Output RMS current is 6.2 A. Input RMS current is supply limit of 6.5 A. 45 VII. CONCLUSIONS CONCLUSIONS AND RECOMMENDATIONS Designing and fabricating a proof-of-concept high-voltage switched-mode three-phase inverter capable of supplying 10kW covered a multitude of design processes and proved to be a challenging endeavor. However, ensuring that a detail-oriented approach was taken in the research, design, construction, and testing stages of this project contributed to its successful completion and thorough presentation in this report. While the original requirements for this project were not met due to limitations in lab test equipment, observed test results yielded successful system performance at lower power levels than intended for nominal operation. Continued development of the proof-of-concept inverter system that has been designed and fabricated for this project will assuredly lead to a productionlevel version with closed-loop feedback and possibly the following recommendations. Given the relatively high-current output capabilities of the Si8234BB HVIC IGBT Gate Driver, up to two more IGBTs can be placed in parallel with each high-side and low-side IGBT in the power stage to increase the system current output capability while maintaining suitable IGBT switching transition times. However, limitations to this increase in current output capability will rise from parasitic inductance in the supply current path and action will be necessary to protect against 46 transient voltages. Limitations will also rise from the inability to sufficiently cool IGBTs while minimizing parasitic inductance by maintaining close IGBT proximity. The development of a floating supply to replace the bootstrap supply topology designed for this project would eliminate the duty cycle limitations on the high-side IGBT. A floating supply able to be ground referenced to the switching output of the half-bridge would provide for unlimited high-side IGBT on time under closed-loop control. Development of a digital microprocessor-based PWM Control system could potentially reduce the amount of space required by the PWM Control block and allow for more versatile or accurate control performance. A digital PWM control system could also have improved noise immunity and temperature tolerance. If analog PWM control is desired, the design of a well laid-out surface mount technology PCB is recommended. The signal voltages of the analog system designed for this project could then be reduced for faster edge transitions so long as the control circuit is effectively protected from noise and electromagnetic interference (EMI). As mention in Section 4.2.3.1, using a ferrite core wrapped with insulated copper foil for the system inductors would result in lower core and copper losses than the inductors in the current proof-of-concept system exhibit. This would decrease the amount of cooling required by the inductors which would increase the system quality. 47 Having made these recommendations, we maintain that the High-Voltage Switched-Mode Power Supply for Three-Phase AC Aircraft Systems that we have designed for this senior project presented to the Electrical Engineering faculty at California Polytechnic State University, San Luis Obispo will fulfill the requirements set by the sponsor, Jeff Brewer, after proper high-power testing, tuning, and no significant design changes have been made. 48 VIII. BIBLIOGRAPHY [1] Power Semiconductor Device, http://en.wikipedia.org/wiki/Power_semiconductor_device, Accessed June 4, 2010. [2] Brewer, John (Jeff), Director of Electrical Engineering, Aircraft Systems Group, General Atomics Aeronautical Systems, Inc. Interview. [3] MIL-STD-704F, http://www.wbdg.org/ccb/FEDMIL/std704f.pdf, Accessed June 5, 2010. [4] International Rectifier Datasheet PD-94625B, http://www.irf.com/product-info/datasheets/data/irgp50b60pd1.pdf, Accessed June 6, 2010. [5] Silicon Labs Datasheet Si8234x, http://www.silabs.com/Support%20Documents/TechnicalDocs/Si823x.pdf, Accessed June 7, 2010. [6] International Rectifier Design Tips DT04-4 Rev A, http://www.irf.com/technical-info/designtp/dt04-4.pdf, Accessed June 7, 2010. [7] ON Semiconductor Datasheet MUR460, http://www.onsemi.com/pub_link/Collateral/MUR420-D.PDF, Accessed June 7, 2010. [8] Unitrode Datasheet UC3637, http://focus.ti.com/lit/ds/symlink/uc1637.pdf, Accessed June 7, 2010. 49 [9] Unitrode Design Note DN-53A, http://focus.tij.co.jp/jp/lit/an/slua184/slua184.pdf, Accessed June 7, 2010. [10] Unitrode Application Note U-102, http://focus.ti.com/lit/an/slua137/slua137.pdf, Accessed June 7, 2010. [11] Analog Devices Datasheet AD823AN, http://www.analog.com/static/imported-files/data_sheets/AD823.pdf, Accessed June 7, 2010. [12] STMicroelectronics Datasheet HCF4538B, http://www.st.com/stonline/books/pdf/docs/2089.pdf, Accessed June 7, 2010. [13] Fairchild Semiconductor Datasheet 74AC00, http://www.fairchildsemi.com/ds/74%2F74AC00.pdf, Accessed June 7, 2010. [14] McLyman, Colonel Wm. T. Transformer and Inductor Design Handbook. Marcel Dekker Inc., Monticello, New York. 2004 [15] PowerLite C-Cores, http://www.metglas.com/downloads/powerlite.pdf, Accessed June 8, 2010. [16] Applied Magnets AWG10-11, http://www.magnet4less.com/product_info.php?products_id=175, Accessed June 8, 2010. 50 APPENDICES A. Schematic The following pages, 51 through 65, contain the Three-Phase Sinusoidal Inverter schematic generated for this project. A B C D UNLESS OTHERWISE SPECIFIED PWM LIMIT LOGIC 3 2 Sheet Sunday, June 06, 2010 Date: 2 Document Number SCHEMATIC, THREE PHASE INVERTER Size A Engineer: J. BREWER, JR. PHASE-C PWM 7 9 15 OUTPUT FILTERS PHASE-B PWM 6 PWM LIMIT TIMING 14 NEUTRAL GATE DRIVER PHASE-A PWM 5 8 13 PHASE-C GATE DRIVER 12 PHASE-B GATE DRIVER SIGNAL BUFFERING 3 NEUTRAL PWM 11 PHASE-A GATE DRIVER IO CONNECTORS 2 4 10 PWM LIMIT LOGIC THREE PHASE INVERTER CONTENTS 3 TABLE OF CONTENTS 4 4 1 5 1. ALL RESISTORS ARE 1/8W, 1% 2. ALL CAPACITORS ARE 10%, 50V. NOTES: 5 1 1 1 of 15 Rev E A B C D A B C D 10 9 8 7 6 5 4 3 2 1 5 DGND -190V_SUPPLY J1 5 15V_RTN NC 5V_RTN 4 12V_RTN 5V_RTN A_B_SD_SWCH [14,15] +5V 5V_RTN N_SD_SWCH [17] +5V 5V_RTN 3 15 8 14 7 13 6 12 5 11 4 10 3 2 9 1 15V_RTN C1 820uF 25V +15V J2 3 C91 560uF C2 4.7uF DGND 2 C3 820uF 25V 15V_RTN C4 4.7uF -15V 2 1 C6 4.7uF SIN_C [3] SIN_B [3] Sheet Sunday, June 06, 2010 Date: 2 Document Number SCHEMATIC, THREE PHASE INVERTER 1 of +12V SIN_A [3] SPARE SPARE 5V_RTN C5 820uF 25V 5V_RTN +5V +5V Size A Engineer: J. BREWER, JR. 15V_RTN -15V +15V THREE PHASE INVERTER IO CONNECTORS C_SD_SWCH [16] +5V 4 15 Rev E 12V_RTN A B C D A B C D C8 0.1uF [2] SIN_B 15V_RTN +15V [2] SIN_A 5 5 10uF 16V C10 R1 100k DGND R4 100k DGND C9 0.1uF 15V_RTN -15V 10uF 16V C7 15V_RTN R5 1.0k - + 4 +15V R3 20k 1/4W OUT -15V U1B TL082 6 5 15V_RTN R2 1.0k - + U1A TL082 2 3 +15V 8 -15V 4 R6 20k 1/4W OUT 7 1 C11 0.1uF 3 SIN_B_BUF [6] [2] SIN_C 15V_RTN +15V SIN_A_BUF [5] [4] TRI_WAVE C12 0.1uF 10uF 16V C13 15V_RTN -15V R7 100k - + U2A 15V_RTN - + TL082 6 5 1 +15V U2B OUT -15V R8 1.0k TL082 2 3 +15V 2 Sheet Monday, June 07, 2010 Date: 2 Document Number SCHEMATIC, THREE PHASE INVERTER 7 Size A R9 20k 1/4W OUT -15V Engineer: J. BREWER, JR. DGND THREE PHASE INVERTER SIGNAL BUFFERING 3 8 V+ V- 4 V+ V4 8 V+ V4 8 V+ V4 3 1 of 15 Rev E SIN_C_BUF [7] TRI_BUF [5,6,7,9] 1 A B C D A B C D 5 -15V R14 20.5k R13 5.62k R12 68.1k R11 5.62k R10 20.5k +15V 5 C14 300pF R16 10k 1/4W 4 R15 47.5k 4 -15V R18 330k R17 100k +15V -15V R20 150k R19 150k +15V C16 0.1uF 3 15V_RTN C15 0.1uF 1 3 18 14 2 15 16 12 13 C17 0.1uF 15V_RTN 15V_RTN 15V_RTN C87 0.1uF 11 10 8 9 UC3637 +VTH -VTH ISET SD CT +E/A -E/A +C/L -C/L +AIN -AIN +BIN -BIN U3 +15V THREE PHASE INVERTER MASTER PWM 3 -VS +VS 6 0.1uF C19 E/AOUT AOUT BOUT 0.1uF C18 15V_RTN 17 4 7 15V_RTN 2 Sheet Monday, June 07, 2010 Date: 2 Document Number SCHEMATIC, THREE PHASE INVERTER Size A Engineer: J. BREWER, JR. -15V 5 4 1 of 15 Rev E PWM_UVLO [5,6,7] NEUTRAL_PWM [11] SLV_THRSH- [5,6,7,9] SLV_THRSH+ [5,6,7,9] TRI_WAVE [3] 1 A B C D A B C D 5 5 [4] SLV_THRSH+ [4] SLV_THRSH- [4] PWM_UVLO [3] SIN_A_BUF [3] TRI_BUF 4 4 15V_RTN 15V_RTN 3 C21 0.1uF C20 0.1uF 15V_RTN C22 0.1uF 1 3 18 14 2 15 16 12 13 11 10 8 9 UC3637 +VTH -VTH ISET SD CT +E/A -E/A +C/L -C/L +AIN -AIN +BIN -BIN U4 +15V THREE PHASE INVERTER PHASE-A PWM 3 -VS +VS 6 0.1uF C24 E/AOUT AOUT BOUT 0.1uF C23 15V_RTN 17 4 7 15V_RTN 2 Sheet Monday, June 07, 2010 Date: 2 Document Number SCHEMATIC, THREE PHASE INVERTER Size A Engineer: J. BREWER, JR. -15V 5 5 1 of A_PWM [10] 1 15 Rev E A B C D A B C D 5 5 [4] SLV_THRSH+ [4] SLV_THRSH- [4] PWM_UVLO [3] SIN_B_BUF [3] TRI_BUF 4 4 15V_RTN 15V_RTN 3 C26 0.1uF C25 0.1uF 15V_RTN C27 0.1uF 1 3 18 14 2 15 16 12 13 11 10 8 9 UC3637 +VTH -VTH ISET SD CT +E/A -E/A +C/L -C/L +AIN -AIN +BIN -BIN U5 +15V THREE PHASE INVERTER PHASE-B PWM 3 -VS +VS 6 0.1uF C29 E/AOUT AOUT BOUT 0.1uF C28 15V_RTN 17 4 7 15V_RTN 2 Sheet Monday, June 07, 2010 Date: 2 Document Number SCHEMATIC, THREE PHASE INVERTER Size A Engineer: J. BREWER, JR. -15V 5 6 1 of B_PWM [10] 1 15 Rev E A B C D A B C D 5 5 [4] SLV_THRSH+ [4] SLV_THRSH- [4] PWM_UVLO [3] SIN_C_BUF [3] TRI_BUF 4 4 15V_RTN 15V_RTN 3 C31 0.1uF C30 0.1uF 15V_RTN C32 0.1uF 1 3 18 14 2 15 16 12 13 11 10 8 9 UC3637 +VTH -VTH ISET SD CT +E/A -E/A +C/L -C/L +AIN -AIN +BIN -BIN U6 +15V THREE PHASE INVERTER PHASE-C PWM 3 -VS +VS 6 0.1uF C34 E/AOUT AOUT BOUT 0.1uF C33 15V_RTN 17 4 7 15V_RTN 2 Sheet Monday, June 07, 2010 Date: 2 Document Number SCHEMATIC, THREE PHASE INVERTER Size A Engineer: J. BREWER, JR. -15V 5 7 1 of C_PWM [11] 1 15 Rev E A B C D A B C D 5 [4] SLV_THRSH+ [3] TRI_BUF 5 - C36 0.1uF 15V_RTN 6 - U7B 5 + 15V_RTN +15V 15V_RTN C35 0.1uF 2 U7A 3 + OUT 4 -15V 7 AD823AN +15V 15V_RTN -15V -15V 1 C37 0.1uF OUT 3 R21 1.0k 15V_RTN D1 SD103A 3 C38 5600pF R22 10k 1/4W 16 VDD Q2/ 9 12+TR(2) 15V_RTN Vss HCF4538B 8 15Cx(2) 14RxCx(2) 13RESET(2) Q2 10 Q1/ 7 11-TR(2) 5 -TR(1) 4 +TR(1) 0.1uF C39 Q1 6 +15V 3 RESET(1) 2 RxCx(1) 1 Cx(1) U8 2 1 8 1 of DUTY_LIMIT [10,11] Sheet Monday, June 07, 2010 Date: 2 Document Number SCHEMATIC, THREE PHASE INVERTER 15V_RTN Size A Engineer: J. BREWER, JR. THREE PHASE INVERTER PWM LIMIT TIMING AD823AN +15V 4 8 V+ V4 8 V+ V4 15 Rev E A B C D A B C D [9] DUTY_LIMIT [6] B_PWM [9] DUTY_LIMIT [5] A_PWM 5 5 10.2k R28 10.2k R23 10.2k R29 15V_RTN D3 SD103A 15V_RTN D2 SD103A 10.2k R24 4 4 20.5k R31 15V_RTN R30 10.2k 20.5k R26 15V_RTN R25 10.2k 15V_RTN R32 10.2k 15V_RTN R27 10.2k 2 1 10 9 U9A U9C 3 74AC00 3 74AC00 8 5 4 13 12 U9B U9D 11 2 +5V 1 9 1 5V_RTN C40 0.1uF Sheet Sunday, June 06, 2010 Date: 2 Document Number SCHEMATIC, THREE PHASE INVERTER B_DRIVE [15] A_DRIVE [14] Size A Engineer: J. BREWER, JR. 74AC00 6 74AC00 THREE PHASE INVERTER PWM LIMIT LOGIC 3 of 15 Rev E A B C D A B C D [9] DUTY_LIMIT 5 [4] NEUTRAL_PWM [9] DUTY_LIMIT [7] C_PWM 5 10.2k R38 10.2k R33 10.2k R39 15V_RTN D5 SD103A 15V_RTN D4 SD103A 10.2k R34 4 4 20.5k R41 15V_RTN R40 10.2k 20.5k R36 15V_RTN R35 10.2k 15V_RTN R42 10.2k 15V_RTN R37 10.2k 10 9 2 1 U10C U10A 3 74AC00 8 74AC00 3 13 12 5 4 U10D U10B 6 2 Sheet Sunday, June 06, 2010 Date: 2 Document Number SCHEMATIC, THREE PHASE INVERTER +5V 1 10 1 5V_RTN C41 0.1uF NEUTRAL_DRIVE [17] C_DRIVE [16] Size A Engineer: J. BREWER, JR. 74AC00 11 74AC00 THREE PHASE INVERTER PWM LIMIT LOGIC 3 of 15 Rev E A B C D A B C D [2] A_B_SD_SWCH [10] A_DRIVE 5 C43 0.1uF 5 5V_RTN C86 0.1uF R43 100k 1/4W 0.1uF C42 8 Si8234BB VDDI NC DT 6 7 DISABLE 4 12 10 GNDB 9 VOB VDDB 11 NC 13 NC GNDI 5 4 15 GNDA 14 VOA VDDA 16 VDDI NC 2 3 PWM 1 U11 5V_RTN +5V 4 C45 C44 +15V C49 C82 C48 C46 0.33uF D6 MUR460 +15V 15V_RTN 0.1uF 0.33uF 10uF 3 15V_RTN C47 0.33uF 0.1uF 10uF D8 MUR460 D7 16V +190V D10 16V D9 16V 2 2 -190V 2 U13 2 U12 IRGP50B60PD1 2 Sheet Monday, June 07, 2010 Date: 2 Document Number SCHEMATIC, THREE PHASE INVERTER Size A Engineer: J. BREWER, JR. 4.7 R45 3.9 R44 THREE PHASE INVERTER PHASE-A GATE DRIVER 3 1 1 3 3 1 1 3 3 11 1 1 of 15 Rev E PHASE_A [18] A B C D A B C D [2] A_B_SD_SWCH [10] B_DRIVE 5 C51 0.1uF 5 5V_RTN C88 0.1uF R46 100k 1/4W 0.1uF C50 8 Si8234BB VDDI NC 4 10 GNDB 9 VOB VDDB 11 DT 6 7 NC DISABLE 12 13 NC GNDI 5 4 15 GNDA 14 VOA VDDA 16 VDDI NC 2 3 PWM 1 U14 5V_RTN +5V 4 C53 C52 +15V C57 C83 C56 C54 0.33uF D13 MUR460 +15V 15V_RTN 0.1uF 0.33uF 10uF 3 15V_RTN C55 0.33uF 0.1uF 10uF D15 MUR460 D14 16V +190V D17 16V D16 16V 2 2 -190V 2 U16 2 U15 IRGP50B60PD1 2 Sheet Monday, June 07, 2010 Date: 2 Document Number SCHEMATIC, THREE PHASE INVERTER Size A Engineer: J. BREWER, JR. 4.7 R48 3.9 R47 THREE PHASE INVERTER PHASE-B GATE DRIVER 3 1 1 3 3 1 1 3 3 12 1 1 of 15 Rev E PHASE_B [18] A B C D A B C D [2] C_SD_SWCH [11] C_DRIVE 5 C59 0.1uF 5 5V_RTN C89 0.1uF R49 100k 1/4W 0.1uF C58 8 Si8234BB VDDI NC 4 10 GNDB 9 VOB VDDB 11 DT 6 7 NC DISABLE 12 13 NC GNDI 5 4 15 GNDA 14 VOA VDDA 16 VDDI NC 2 3 PWM 1 U17 5V_RTN +5V 4 C61 C60 +15V C65 C84 C64 C62 0.33uF D20 MUR460 +15V 15V_RTN 0.1uF 0.33uF 10uF 3 15V_RTN C63 0.33uF 0.1uF 10uF D22 MUR460 D21 16V +190V D24 16V D23 16V 2 2 -190V 2 U19 2 U18 IRGP50B60PD1 2 Sheet Monday, June 07, 2010 Date: 2 Document Number SCHEMATIC, THREE PHASE INVERTER Size A Engineer: J. BREWER, JR. 4.7 R51 3.9 R50 THREE PHASE INVERTER PHASE-C GATE DRIVER 3 1 1 3 3 1 1 3 3 13 1 1 of 15 Rev E PHASE_C [18] A B C D A B C D [2] N_SD_SWCH 5 C67 0.1uF [11] NEUTRAL_DRIVE 5 5V_RTN C90 0.1uF R52 100k 1/4W 0.1uF C66 8 Si8234BB VDDI NC 4 10 GNDB 9 VOB VDDB 11 DT 6 7 NC DISABLE 12 13 NC GNDI 5 4 15 GNDA 14 VOA VDDA 16 VDDI NC 2 3 PWM 1 U21 5V_RTN +5V 4 C69 C68 +15V C73 C85 C72 C70 0.33uF D27 MUR460 +15V 15V_RTN 0.1uF 0.33uF 10uF 3 15V_RTN C71 0.33uF 0.1uF 10uF D29 MUR460 D28 16V +190V D31 16V D30 16V 2 2 -190V 2 U22 2 U21 IRGP50B60PD1 2 Sheet Monday, June 07, 2010 Date: 2 Document Number SCHEMATIC, THREE PHASE INVERTER Size A Engineer: J. BREWER, JR. 4.7 R54 3.9 R53 THREE PHASE INVERTER NEUTRAL GATE DRIVER 3 1 1 3 3 1 1 3 3 14 1 1 of 15 Rev E NEUTRAL [18] A B C D A B C D 5 [15] PHASE_B [14] PHASE_A 5 160uH L2 160uH L1 4 4 PWR_GND C76 20uF 400V PWR_GND C74 20uF 400V C77 20uF 400V C75 20uF 400V SIN_B_OUT SIN_A_OUT 3 [17] NEUTRAL [16] PHASE_C 160uH L4 160uH L3 2 PWR_GND C78 20uF 400V -190V C81 3300uF 350V C80 3300uF 350V +190V Sheet Sunday, June 06, 2010 Date: 2 Document Number SCHEMATIC, THREE PHASE INVERTER 1 15 1 SIN_C_OUT PWR_GND C79 20uF 400V Size A Engineer: J. BREWER, JR. THREE PHASE INVERTER OUTPUT FILTERS 3 of 15 Rev E A B C D 66 B. Bill of Materials Table B.1 – Bill of Materials and Donated Items Item Hardware CS Hyde Metalized Mylar Tape, 2.2 mil. Thick, 1' x 72 yds SPDT 6A F.LVR Switch SPDT 6A R.LVR Switch D-Sub 15 Pin Male D-Sub 15 Pin Female Pre-Punched IC-Spacing Perfboard 2-3/4"x6" 2-Sided Cooper Clad Board 4.5"x6.125" Assorted Cable Ties 8" 8-10 Stud Ring Terminals Door Handles PCB Standoff 1" PCB Standoff 2 1/4" Crimp Pins Male Plastic Rectangular Crimp Pin Receptacle Corner Brace 1-1/2" White Screw Bumper Ring Tongue Connector #4-40 x 1/2' Round Head - Slotted Bolt #4-40 x 1/2' Round Head - Phillips Bolt #4-40 Nut #6-32 x 3/8' Round Head - Slotted Bolt #6-32 Nut #6 Lock Washer #6 SAE Washer #10-32 x 3/8" Round Head - Slotted Bolt #10-32 x 1/2" Round Head - Slotted Bolt #10-32 x 5/8" Round Head - Slotted Bolt #10-32 x 3/4" Round Head - Slotted Bolt #10-32 x 1" Rounded - Slotted Bolt #10-32 x 1/2" Flat Head- Phillips Bolt #10-32 Nut #10 Lock Washer #10 SAE Washer Aluminum Flat Plate Unit Price ($) 13.5 3.69 3.69 2.49 2.49 3.99 3.99 5.99 0.14 3.49 0.45 0.35 0.1 0.5 0.63 0.49 0.25 0.1 0.1 0.03 0.1 0.03 0.06 0.03 0.1 0.1 0.1 0.1 0.1 0.1 0.03 0.06 0.03 9.85 Quantity 1 2 1 1 1 3 3 1 21 2 4 2 15 2 4 8 13 12 4 10 16 16 28 40 8 8 5 16 9 8 59 75 69 1 Total Price ($) 13.5 7.38 3.69 2.49 2.49 11.97 11.97 5.99 2.94 6.98 1.8 0.7 1.5 1 2.52 3.92 3.25 1.2 0.4 0.3 1.6 0.48 1.68 1.2 0.8 0.8 0.5 1.6 0.9 0.8 1.77 4.5 2.07 9.85 67 Polyolenfin Heat Shrink Tubing 3/32" Polyolenfin Heat Shrink Tubing 3/32" IC Socket Mach Pin WW 8Pos Gold - AR08-HZW/T-R IC Socket Mach Pin WW 14Pos Gold - AR14-HZW/T-R IC Socket Mach Pin WW 16Pos Gold - AR16-HZW/T-R IC Socket Mach Pin WW 18Pos Gold - AR18-HZW/T-R Square Machine Post - 100 Coaxial DC Power Jack Coaxial DC Power Plug Electronics Texas Instruments - OpAmp Dual JFET Input TL082CP Unitrode - SM Crtl for DC Motor Drive - UC3637 Analog Devices Inc - OpAmp JFET R-R Dual AD823AN Fairchild Semiconductor - Quad 2 Input Nand 74AC00B International Rectifier - IGBT - IRGP50B60PD1 STMicroelectronics - Multivibrator - HCF4538B Silicon Labs - High Side / Low Side Driver - Si8234BB Mallory CGS332T350X5L 3300μF 350VDC Capacitor United Chemi-Con - Cap Elect 820uF 50V Panasonic - ECG - Cap 4.7uf 25V Cer - PCC2251CT-ND TDK Corp - Cap Cer 10uF 16V X7R RAD FK20X7R1C106K Panasonic - ECG - Cap Elect 10uF 400V - EEUED2G100 BC Components - Cap Cer .10UF 50V K104K15X7RF5TH5 Murata Electronics NA - Cap Cer 300pF 50V Murata Electronics NA - Cap Cer 5600pF 50V TDK Corporation - Cap Cer 0.33uF 50V FK24X7R1H334K United Chemi-Con - Cap Elect 560uF 50V Diodes Inc - Diode Schottky 40V 400MW - SD103A-T ON Semiconductor - Switchmode -Diode 4A 600V Murata Electronics NA - Trim Pot Cerm 100kOhm Stackpole Electronics Inc - RES 1kOhm 1/8W 5% Murata Electronics NA - Trim Pot Cer 20kOhm Yageo - Res 20.5kohm 1/4W 1% Metal Film Stackpole Electronics - Res MF 1/8W 5.62kOhm 1% Stackpole Electronics Inc - Res MF 1/8W 68.1kOhm 1% 1.79 1.95 1.69 2.53 2.9 2.9 4.99 3.29 3.29 1 1 3 2 5 4 1 4 4 1.79 1.95 5.07 5.06 14.5 11.6 4.99 13.16 13.16 0.77 7.28 2 4 1.54 29.12 5.64 1 5.64 0.6 8.28 0.65 3.71 71.45 1.29 0.79 2 16 1 4 2 3 3 1.2 132.48 0.65 14.84 142.9 3.87 2.37 0.83 3 2.49 0.67 8 5.36 0.06 0.3 0.62 51 1 1 3.06 0.3 0.62 0.21 0.86 0.65 0.65 1.38 0.09 1.38 0.57 0.15 12 1 5 8 8 4 3 6 2 2.52 0.86 3.25 5.2 11.04 0.36 4.14 3.42 0.3 0.15 1 0.15 68 Stackpole Electronics Inc - Res MF 1/8W 47.5kOhm 1% Murata Electronics NA - Trim Pot Cerm 10kOhm 12Trn Stackpole Electronics Inc - Res MF 1/8W 330kOhm 1% Stackpole Electronics Inc - Res MF 1/8W 150kOhm 1% Stackpole Electronics Inc - Res MF 1/8W 10.2kOhm 1% Stackpole Electronics Inc - Res MF 1/8W 3.9Ohm 1% Stackpole Electronics Inc - Res MF 1/8W 4.7Ohm 1% Wire UL- Stranded Hookup Wire - 22AWG - Red 25' UL- Stranded Hookup Wire - 22AWG - Green 25' UL- Stranded Hookup Wire - 22AWG - Black 25' 10AWG - Mil Spec - M81044/ 9-10-9 - White 10' 10AWG - Mil Spec - M81044/ 9-10-0 - Black 10' 26AWG - Stranded HookupWire - Red - 25' 26AWG - Stranded HookupWire - Black - 25' 26AWG - Assorted Stranded HookupWire - 25' Magnet Wire / Winding Wire - 10 AWG, 11LBS Wire Roll Repl 30AWG Blue 50' Wire Roll Repl 30AWG Yellow 50' Wire Roll Repl 30AWG Green 50' Wire Roll Repl 30AWG Orange 50' Donated Items Plexiglass Project Box 22 3/8"X 20 1/8" X 9 1/4" dsPIC Funtion Generator Electrocube 945B 20μF 400VDC Capacitor Powerlite C-Core AMCC 50 Powerlite Bobbin AMCC-50BOB 0.15 1 0.15 1.81 2 3.62 0.15 1 0.15 0.15 2 0.3 0.15 0.15 0.15 16 4 4 2.4 0.6 0.6 2.33 2.33 2.33 4 4 2.25 2.25 4.99 124.99 9.12 9.12 9.12 9.12 1 1 1 1 1 1 1 1 1 1 1 1 1 Grand Total 2.33 2.33 2.33 4 4 2.25 2.25 4.99 124.99 9.12 9.12 9.12 9.12 Quantity 1 1 6 8 8 757.27 69 C. Circuit Board Layout Fig. C.1 – Microsoft PowerPoint Circuit Board Layout Source: John Brewer, Jr. and Kamaljit Bagha 70 D. Circuit Board IC and Component Locations Fig. D.1 – IC and Component Circuit Board Location Source: John Brewer, Jr. and Kamaljit Bagha 71 E. Hardware Configuration and Layout Fig. E.1 – Hardware Configuration and Layout Source: Kamaljit Bagha 72 Fig. E.2 – Test Bench Setup Source: Kamaljit Bagha