So, I've got an #electronics
problem that's been bothering me most of this week. I built a continuity tester for the QA department at work. The reason for making it bespoke like that is to eliminate operator error. In other words, I had to idiot-proof it.
The tester has two big lights on it, one green and one red.
When the tester is powered on, the red light goes on.
If a part is inserted into the stand and completes the circuit, the red light goes off and the green light goes on. The schematic I linked is more or less how the tester works in principle. One LED is illuminated until it gets a signal from one of the analog pins (continuity), at which point it switches to the other LED.
The problem is that right now it's using an #Arduino
to drive a pair of transistors to switch between two 12V high-powered LEDs. I say problem because I think using an Arduino for this is total overkill, even for idiot-proofing.
What I want to make is a continuity tester that runs two LEDs, red when on and green when continuity is detected, using the absolute bare minimum of components. I don't want anything more sophisticated than a #555 timer chip on this setup; just caps, resistors, transistors, and maybe a relay or two. There's plenty of #DIY
continuity tester diagrams out there, but they all work on the ON/OFF principle when I need something more like A/B if that makes sense.