dragster73
New Member
I am interested in building a small LED readout for notifying me when a transistor on a circuit board has been pulled to ground.
Let me explain a little.
I repair pinball machines and video games. I have a test fixture i have built for testing the pinball circuit boards. I have 28 TIP102 transistors that are used for turning on and off coils on the machine. All 28 transistors are labeled say Q1 - Q28. I want to make a small two digit LED readout that would light up the number of a transistor when it is activated or even shorted. The transistor itself when turned on completes the path to ground for the coil. Im my case i will not have the coils hooked up. I just want the outputted ground signal to light the LED to the associated transistor.
Example Q23 is shorted, or activated by the built in test software.
I want the LED display to read Q23.
I know the "Q" will be a given and i can fix 14 segment LED readout for the letter "Q"
What i need is a way to light the proper number from a single ground.
Any Ideas? Or any Related WEB pages?
Let me explain a little.
I repair pinball machines and video games. I have a test fixture i have built for testing the pinball circuit boards. I have 28 TIP102 transistors that are used for turning on and off coils on the machine. All 28 transistors are labeled say Q1 - Q28. I want to make a small two digit LED readout that would light up the number of a transistor when it is activated or even shorted. The transistor itself when turned on completes the path to ground for the coil. Im my case i will not have the coils hooked up. I just want the outputted ground signal to light the LED to the associated transistor.
Example Q23 is shorted, or activated by the built in test software.
I want the LED display to read Q23.
I know the "Q" will be a given and i can fix 14 segment LED readout for the letter "Q"
What i need is a way to light the proper number from a single ground.
Any Ideas? Or any Related WEB pages?