Cobra3 Measuring module function generator
12111.00
PHYWE Systeme GmbH & Co. KG
Robert-Bosch-Breite 10
D-37079 Göttingen
Telephone +49 (0) 551 604-0
Fax
+49 (0) 551 604-107
Internet
www.phywe.com
E-mail
info@phywe.de
Operating instructions
The unit complies
with the corresponding
EC guidelines.
Fig. 1: Measuring module for Cobra3 interface, Function Genarator.
CONTENTS
1
SAFETY PRECAUTIONS
2
PURPOSE AND DESCRIPTION
3 HANDLING
3.1 Starting operation
3.2 Experiment description
4
NOTES ON OPERATION
5
TECHNICAL SPECIFICATIONS
6
LIST OF EQUIPMENT
7
NOTES ON THE GUARANTEE
8
WASTE DISPOSAL
1
SAFETY PRECAUTIONS
• Carefully read these operating instructions completely
before operating this instrument. This is necessary to avoid
damage to it, as well as for user-safety.
• Only use the instrument in dry rooms in which there is no
risk of explosion.
• Only use the instrument for the purpose for which it was
designed.
• The measuring module for Cobra3 interface - Function
Generator - 12111.00, called FG-Module in the following, is
developed for only use with the Cobra3 Basic Unit
12150.00.
2 PURPOSE AND DESCRIPTION
The FG-Module (see Fig. 1) is an instrument that have been
developed specifically for use in demonstrations and
practical work in the teaching of Physics in schools and
colleges. The FG-Module can be used as voltage or as
current supply for the computer assisted experiments in
acoustics and electricity. You can find the list of experiments
with FG-Module at the end of this Operating Instructions.
3 HANDLING
The measuring module may only be plugged onto the
MODUL plug rod when the COBRA interface is switched off.
Both plastic bushings integrated in the module casing fit into
the safety sockets of the used analogue input. Electric
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connection with this analogue input is assured over the plug
rod.
Two 4 mm safety sockets on the front part of the FG module
provides the output signals. This is the FG module
input/output port for generating sinusoidal, square-wave and
triangular-wave signals, direct voltages and frequency- or
voltage-ramps. The module can be used as a voltage or
current source: If it is used as a voltage source, the actual
frequency and current can be displayed and measured
during operation. If it is used as a current source, the actual
frequency and voltage can be displayed and measured.
In the side wall of the FG module there is a low voltage
socket for connection of the power supply 12151.99 or
another Cecomplying power supply 12 V–/> 6 W (positive on
the inside).
3.1 Starting operation
Connect (plug in) the FG module to the Cobra3 interface.
Connect the power supply 12151.99 to the FG Module first,
then the second power supply to the Cobra3 interface.
3.2 Experiment description
The experiment description is based on an example: the RLC
Circuit with Cobra3 (order number: P2440611).
3.2.1 The experimental set up is shown in Fig. 2a and Fig. 2b
(or Fig. 3a, 3b):
a. Parallel tuned RLC circuit:
L
= 2 mH, (300 turns)
C
= 1 µF
R_d = 470 ohm, 1 kohm, infinity;
R_c = 1 kohm
Fig. 2a: Parallel tuned RLC circuit.
Fig. 2b: Parallel tuned RLC circuit (schematic).
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b. Series tuned RLC circuit:
L
= 2 mH, (300 turns)
C = 0.1 µF
R_d = 0 ohm, 10 ohm, 47 ohm;
R_c = 47 ohm
Fig. 3a: Series tuned RLC circuit.
Fig. 3b: Series tuned RLC circuit (schematic).
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3.2.2 Connect the COBRA3 Basic Unit to the computer port COM1, COM2 or to USB port (for USB computer port use USB to
RS232 Converter 14602.10). Start the measure program and select Cobra3 Universal Writer Gauge. Begin the measurement
using the parameters given in Fig. 4.
Fig. 4: Measuring parameters.
3.2.3 For the measurement of current and voltage amplitudes the "Survey Function" of the Measure Software is used (see
Fig. 5). The measured values of the total current and total voltage as a function of frequency in the series tuned circuit are
shown in Fig. 6 and Fig. 7. (For the parallel tuned circuit is the measurement procedere similar.)
Fig. 5: Measurement of current and voltage amplitudes with the "Survey Function".
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Fig. 6: Total current as a function of frequency in the series tuned circuit. Curves recorded for different resistors (top down): R_d = 0 Ω, 10 Ω, 47 Ω.
Fig. 7: Total voltage as a function of frequency in the series tuned circuit. Curves recorded for different resistors (top down): R_d = 0 Ω, 10 Ω, 47 Ω.
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3.2.4 The total resistance as a function of frequency
R_tot = R_i + R_c + R_d + R_l
can be determined from the current and voltage values as it
is shown in Fig. 8 (for R_d = 0) using the following
parameters:
Open both measurement files - voltage and current as a
function of frequency. In the Measurement / Assume channel
window select the corresponding voltage (current) curve.
In the Measurement / Information / x-Data window select:
Title:
Frequency
Symbol:
f
Unit:
Hz
Digits beyond point:
4
In the Measurement / Information / Channels window select:
Title (for current curve):
Current (R = 0 ohm)
Symbol :
I
Unit :
mA
Digits beyond point:
4
first source channel:
Voltage (R = 0 ohm)
Title (for voltage curve):
Symbol:
Unit :
Digits beyond point:
In the Analysis / Channel modification window select:
first source channel: Vol
Voltage (R = 0 ohm)
second source channel: Cur
Current (R = 0 ohm)
Operation:
f : = Vol/Cur
Destination channel:
add new y-channel
Title:
Resistor
Symbol:
R
Unit:
ohm
Press the button "Continue" and you will receive the total
resistance as a function of frequency.
The measured resonance frequency of a damped in series
oscillator is
f_exp = (10.6 ± 0.3) kHz
This value is close to the theoretical value of the resonance
frequency of a free oscillator
f_theo = 11.26 kHz
Voltage (R = 0 ohm)
U
mV
4
Fig. 8: Total resistance as a function of frequency in series tuned circuit.
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4 NOTES ON OPERATION
This high-quality instrument fulfills all of the technical
requirements that are compiled in current EC guidelines. The
characteristics of this product qualify it for the CE mark.
This instrument is only to be put into operation under
specialist supervision in a controlled electromagnetic
environment in research, educational and training facilities
(schools, universities, institutes and laboratories).
This means that in such an environment, no mobile phones
etc. are to be used in the immediate vicinity. The individual
connecting leads are each not to be longer than 2 m.
The instrument can be so influenced by electrostatic charges
and other electromagneric phenomena that it no longer
functions within the given technical specifications. The
following measures reduce or do away with disturbances:
Avoid fitted carpets; ensure potential equalization; carry out
experiments on a conductive, earthed surface, use screened
cables, do not operate high-frequency emitters (radios,
mobile phones) in the immediate vicinity. Following a
blackout failure, operate the on/off switch for a reset.
This instrument corresponds to Class A, Group 1 of the
EN 55011 Standard and can only be operated without
limitation outside of residential areas. Should electromagnetic disturbances occur in surrounding residential areas
although operation is limited to the technical room of a school
or other training facility, then it can be demanded of the
operator that he carries out adequate measures (e.g.
screening, greater distance, reduction in the operating time)
at his own cost.
When the instrument is connected to a test object, the
permissible interfering radiation may be exceeded. The
operator must take all necessary precautions here to ensure
that proper functioning of other instruments in the vicinity is
not impaired.
The Operating Instructions for the Cobra3 Basic Unit
12150.00 is to be carefully followed whenever FG module
12111.00 is used in the experiment.
5 TECHNICAL SPECIFICATIONS (typical for 25°C)
Operating temperature range 5... 40°C
Relative humidity
< 80%
Signals
direct voltages, sinusoidal,
square-wave and triangularwave signals, and frequencyor voltage-ramps.
Setting of the frequency
manually or frequency ramp
Output
short circuit proof
Dimensions (mm)
approx. 50 x 100 x 52 (W,H,D)
Weight
approx. 140 g
The module can be used as a voltage or current source.
Voltage source:
Amplitude
Offset voltage
Output current
0... 10 V
Interval 5 mV
-10... +10 V (adjustable)
0... 150 mA (continuous
operation)
max. 200 mA
(short operation ~ 100 sec)
Frequency ranges
5... 200 Hz
Interval 1 Hz
200 Hz... 20 kHz
Interval 10 Hz
If it is used as a voltage source, the actual frequency and
current can be displayed and measured during operation.
Current source:
Amplitude
Offset current
Frequency ranges
0... +100 mA
Interval 5 mA
-100... +100 mA
5... 200 Hz
Interval 1 Hz
200 Hz... 1 kHz
Interval 10 Hz
If it is used as a current source, the actual frequency and
voltage can be displayed and measured.
6 LIST OF EQUIPMENT
P2440611 RLC Circuit with Cobra3:
Cobra3 BASIC-UNIT
Cobra3 BASIC-UNIT, USB
Power supply 12 V–/2 A
Data cabel, plug/socket, 9 pole
Software Cobra3 Universal recorder
Cobra3 Measuring modul function
generator
Coil 300 turns
Connection box
Carbon resistor 10 Ω, 1 W, G1
Carbon resistor 47 Ω, 1 W, G1
Carbon resistor 470 Ω, 1 W, G1
Carbon resistor 1 kΩ, 1 W, G1
Capacitor 1 µF/ 250 V, case G2
Capacitor 100 nF/250 V, case G1
Connecting plug 4 mm/19 mm, white
Connecting cord, 25 cm, 32 A, red
Connecting cord, 25 cm, 32 A, blue
Connecting cord, 50 cm, 32 A, red
Connecting cord, 50 cm, 32 A, blue
12150.00 or
12150.50
(2x) 12151.99
14602.00
14504.61
12111.00
(2x)
(2x)
(2x)
(2x)
(2x)
(2x)
06513.01
06030.23
39104.01
39104.62
39104.15
39104.19
39113.01
39105.18
39170.00
07360.01
07360.04
07361.01
07361.04
Following Experiments can be performed with the FGModul:
P2410115 Ohm's Law with Cobra3
P2410915 Characteristic curves of semiconductors with
Cobra3
P2411315 Second order conductors. Electrolysis with
Cobra3
P2420215 Switch-on behaviour of a capacitor and inductivity with Cobra3
P2440215 Magnetic induction with Cobra3
P2440311 Inductance of solenoids with Cobra3
P2440411 Coil in the AC circuit with Cobra3
P2440515 Capacitor in the AC circuit with Cobra3
P2440611 RLC Circuit with Cobra3
P2440915 High-pass and low-pass filters with Cobra3
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7 NOTES ON THE GUARANTEE
We guarantee the instrument supplied by us for a period of
24 months within the EU, or for 12 months outside of the EU.
Excepted from the guarantee are damages that result from
disregarding the Operating Instructions, from improper
handling of the instrument or from natural wear.
The manufacturer can only be held responsible for the
function and technical safety characteristics of the
instrument, when maintenance, repairs and alterations to the
instrument are only carried out by the manufacturer or by
personnel who have been explicitly authorized by him to do
so.
8 WASTE DISPOSAL
The packaging consists predominately of environmentally
compatible materials that can be passed on for disposal by
the local recycling service.
Should you no longer require this product, do
not dispose of it with the household refuse.
Please return it to the address below for proper
waste disposal.
PHYWE Systeme GmbH & Co. KG
Abteilung Kundendienst (Customer Service)
Robert-Bosch-Breite 10
D-37079 Göttingen
Phone +49 (0) 551 604-274
Fax
+49 (0) 551 604-246
8
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12111.00/2409