Modern Logic Probe
PART NO. 2222272
Modern Logic Probe was designed to measure 0´s and 1´s logics and for working with a voltage from 5V to 12VDC. This project was based in an LM358 and a common cathode RG LED to its monitorial. The Modern Logic Probe is capable of being adjusted to 0V with help of a couple of trimmers of 5K for turning off the RG LED. Using the project, the result is a RED led turns on when a ´zero logic´ is applied or a Green LED turns on when a ´one logic´ is applied. For more information about this project, go to the following websites: http://www.instructables.com/id/Modern-Logic-Probe/
Time required: 3 hours depending on experience
Experience Level: Beginner
Required tools and parts:
Soldering Iron & Solder Roll
Wire Cutter & Stripper
Rotary Drill & Drill bits of 3/16" & 1/4"
1 Hex nut of 4mm
#22 Wire, 2meters
Plastic Color Tape
Qty Jameco SKU Component Name
1 23966
It´s the main component of this project.
1 112206
An important component for this project
OP Amp Dual General Purpose ±16 Volt32 Volt 8-Pin MDIP Rail
Socket IC 08 Pin Dual Wipe Solder tail Low Profile 0.30 Inch Width
1 18922
A vital component for this project
Case ABS Speedy 3.125x2x.875
1 105100 Prototype Builder 1.6" X2.7" PCB Epoxy Glass 0.062" Thick 0.1" Hole Spacing 0.08" Pad Size
It´s imperative that this component be utilized in the project.
1 2185483
An indispensable component for this project
Alligator Clip Test Leads - 2 Pack Red and Black
1 77738
A necessary component for this project
Test Leads with Alligator Screw On Tips 1 Red 1 Black 40 Inch
2 43078 1/2 Watt 3/8" Square Trimming Potentiometer 5k Ohm
It´s imperative that this component be utilized in the project.
1 2125181 5mm Water Clear RGB LED - Common Ground

An indispensable component for this project
1 14277 Led Mounting Hardware T1-3/4 Clear Standard
A necessary component for this project
1 35991 400 VOLT 1 AMP DO-41 SILICON RECTIFIER DIODE400 VOLT 1 AMP DO-41 SILICON RECTIFIER DIODE
It´s necessary that this component be utilized in the project.
1 691121 Resistor Carbon Film 12k Ohm 1/4 Watt 5% (Bag of 100)
An important component for this project
2 690646
A vital component for this project
1
An important component for this project
1
690961
419127
An important component for this project
1 691690
Indispensable component for this project
Resistor Carbon Film 120 Ohm 1/4 Watt 5% (In Bags of 10 and 100)
Resistor Carbon Film 2.7k Ohm 1/4 Watt 5% (In Bags of 10 and 100)
Resistor Carbon Film 3.3m Ohm 1/4 Watt 5% (Bag of 100)
HEAT SHRINK TUBING,FIT-221B-1/16-BLACK,4 FEET,BLACK POLYOLEFIN
Step 1 - List of Materials
1 LM358N
1 Socket IC 08 Pin Dual Wipe Solder tail Low Profile 0.30 Inch Width
1 Case ABS Speedy 3.125x2x.875
1 Prototype Builder 1.6" X2.7" PCB Epoxy Glass 0.062" Thick 0.1" Hole
Spacing 0.08" Pad Size
1 Alligator Clip Test Leads - 2 Pack Red and Black
1 Test Leads with Alligator Screw On Tips 1 Red 1 Black 40 Inch
2 1/2 Watt 3/8" Square Trimming Potentiometer 5k Ohm
1 5mm Water Clear RGB LED - Common Ground
1 Led Mounting Hardware T1-3/4 Clear Standard
1 400 VOLT 1 AMP DO-41 SILICON RECTIFIER DIODE (1N4004)
1 Resistor Carbon Film 12K Ohm 1/4 Watt 5% (Bag of 100)
2 Resistor Carbon Film 120 Ohm 1/4 Watt 5% (In Bags of 10 and 100
1 Resistor Carbon Film 2.7K Ohm 1/4 Watt 5% (In Bags of 10 and 100)
1 Resistor Carbon Film 3.3M Ohm 1/4 Watt 5% (Bag of 100)
1 HEAT SHRINK TUBING, FIT-221B-1/16-BLACK, 4 FEET, BLACK POLYOLEFIN
Step 2 - Diagram 1
In this diagram 1, you can see a LED lit and its light is red because a 'zero' logic is being applied in the point of probe (connected to pins: 3 & 6) of your project. Also note that the LED is a type of common ground connection, so you can simply connect to their respective resistors so that you can monitor the result either 'zero' or 'one'. According to the project, you will connect pin 4 & diode's positive terminal to GND & positive terminal of this project (alligator clips black & red) respectively while diode's negative terminal to pin 8 from
LM358.

Step 3 - Diagram 2
In this diagram 2, you can see a LED lit and its light is green because a 'one' logic is being applied in the point of probe (connected to pins: 3 & 6) of your project. Also note that the LED is a type of common ground connection, so you can simply connect to their respective resistors (checking colors green and red to pins 1 & 7 respectively) so that you can monitor the result either 'zero' or 'one'. According to the project, you will connect pin 4 & diode's positive terminal to GND & positive terminal of this project (alligator clips black & red) respectively while diode's negative terminal to pin 8 from LM358. You will besides connect to pins: 3 & 6 a resistor of 3.3 M Ohms while its terminal remaining to a resistor of 12K and trimmer of 5K. Then you should connect the terminal remaining of 12K resistor to diode's positive terminal and 2.7K resistor while the terminal remaining of 2.7K to the other trimmer of 5K. Now, observe that the middle terminal of each trimmer of 5K should be connected to the pins: 1 & 5 where the first has connected a resistor of 2.7K while the second has both a resistor of 12K and other of 3.3MOhms, and without forgetting that you should connect both terminal remaining of the two trimmer of
5K to GND.

Step 4 - Point of Probe 1
For making a point of probe, take a test lead of those included in your kit then use and adjust it using a hex nut of 4mm held from outside of the project's box. For doing this proceeding, follow the next steps:
Point of probe 2
Point of probe 3
Point of probe 4
Point of probe 5
Step 5 - Point of Probe 2
Using a wire cutter for breaking literally the plastic area of your test lead so like in the photo, take a test lead included in your kit for carrying out the proceeding.
Step 6 - Point of Probe 3
Now, let's pull down the long plastic part of your test lead only.
That is, leave it like it looks in the photo.
Step 7 - Point of Probe 4
After carrying out the step #6, use a soldering iron and a wire cutter to remove the rest of the plastic on your test lead. Once the test lead is clean, cut the wire at a short length: for instance, one or a couple of inches.
Step 8 - Point of Probe 5
Once you cut the wire and without plastic insulation in your prospective point of probe, you will also need a hex nut of 4mm.

Step 9 - Enclosure 1
Taking the ABS plastic enclosure, drill a hole by using a drill bit of
3/16" for manipulating the rotary drill as many as necessary until you can insert the point of probe perfectly.
Step 10 - Enclosure 2
Now, install the point of probe in your enclosure by using the hex nut of 4mm to adjust it from outside of the box.
Step 11 - Enclosure 3
In the part of the plastic enclosure showed in the photo, drill a hole by using a drill bit of 1/4" to install the LED socket later.
Step 12 - Enclosure 4
Now, install the LED socket.
Step 13 - Enclosure 5
In this step, you are going to use heat shrink tubing in the point of probe terminal. Look the next photo:

Step 14 - RGB LED to RG LED
So that the RGB LED becomes a RG LED, it's necessary to cut the blue terminal of the RGB LED.
Step 15 - Enclosure 6
Once installed the LED socket, insert the RG LED prepared in the previous step. In this step, you can use heat shrink tubing of 1/16" like insulation in LED terminals too.
Step 16 - Alligator Clips
To prepare the alligator clips, you can use Alligator clip test leads:
2-pc one red and one black. With these alligator clips in your hands, you should cut them either in two parts or 3/4 of wire for using according to your convenience.
Step 17 - Enclosure 7
Now, take your ABS plastic enclosure and do a hole by using drill bit of 3/16" in the opposite side of the other hole where you installed the point of probe.
Step 18 - Enclosure 8
In the hole done previously, install the alligator clips: red & black by passing the wires through the hole by doing a knot for supporting them inside of the enclosure.

Step 19 - Installing Components 1
Taking the PCB, install the two trimmers of
5K and the IC socket of 8 pins.
Step 20 - Installing Components 2
In this step, install the resistors of 12K, 2.7K, 3.3M
Ohms and the diode 1N4004.
Step 21 - Installing Components 3
For doing connections to the trimmers of 5K, I'm using green, brown and white wire. Note that you should check the project's diagram constantly to avoid errors.
Step 22- Installing Components 4
Now, install the two resistors of 120 Ohms.
Step 23 - Drawing the Wires for Doing Connections 1
Complete the connections to GND and draw a red and other green wire from the resistors of 120 Ohms to be connected to the red & green LED terminal respectively.

Step 24 - Drawing the Wires for Doing Connections 2
Now, draw a black wire for being connected to the common ground of your LED installed previously, and you should also draw a yellow wire between the pins: 3 & 6 from the IC socket to be connected later to the point of probe. Finally, draw a couple of wires from the positive and negative terminal of this kit so that you can use them like connection to red and black alligator clips respectively.
Step 25 - Doing Connections 1
In this step, connect the three terminals of the RG LED by using its respective color wire for each LED color terminal. That is, green, black & red wire should be connected to green, common ground and red LED terminal respectively while the yellow wire should be connected to the point of probe. Note that I'm using color tape to identify each connection that obviously it's optional but you can use them if you want.
Step 26 - Doing Connections 2
For ending the connections, you should join GND & positive terminal of your project to the black & red alligator clip terminal respectively.
In these terminals, I used color tape dark blue and red to identify them.
Step 27 - Adjusting the Project
In this step, you should adjust the project by manipulating the trimmers of 5K. That is, just adjust a trimmer by using a screwdriver until the LED is lit and no more so that you can obtain a red LED lit when a 'zero' logic is applied. Then just adjust the other trimmer by using a screwdriver until the LED is lit and no more so that you can obtain a green LED lit when an 'one' logic is applied. Once adjusted, until your project works correctly, you can close the box by using the screws included in this kit.
Step 28 - Completing the Project
Once closed the plastic box of your project, you can see its look and use it for checking your logic circuits that you do since now.

Step 29 - Checking the Project 1
For checking if the project functions correctly, you have to use it. The suggestion is that this kit be utilized for checking a '0' logic and observe the color of light lit: in this case, it should be red color. Now, a fast way would be to take any circuit that you have done and if it works with a voltage from 3V to 12VDC, you can check your project by connecting the black & red alligator clips to GND & Vcc respectively where you will check a 'zero' logic on GND of your own project.
Step 30 - Checking the Project 2
For checking if the project functions correctly, you have to use it.
The suggestion is that this kit be utilized for checking a '1' logic and observe the color of light lit: in this case, it should be green color. Now, a fast way would be to take any circuit that you already have done and if it works with a voltage from 3V to 12VDC, you can check your project by connecting the black & red alligator clips to GND & Vcc respectively where you will check an 'one' logic on Vcc of your own project.