This is a great idea. Fewer wires for quick prototype tests, and (I assume) no ground loops to avoid.

If you don’t find one LensRentals is great for equipment you want to test before you buy (they will often give a discount on buying the exact piece of equipment you rented).

Nope, I just drew a trace wrong in the schematic, and putting a resistor under the transistor pin corrects the error...

I just finished writing a description of it, here: www.oihdesigns.com/mannvoltmete...

(Short answer, I open a MOSFET after a 0 reading to break a bridge and that puts a 2.5vdc through a 500k resistor to one probe, and I check if the other probe sees it.)

Thanks!

I have a long write-up here, which also links to a GitHub where I’ve published my designs: www.oihdesigns.com/arduino-

You can get remote control relays for this. I was adding some light switches in my house and using remote controls saved a lot of wire and hassle.

I don’t know why Bluesky hates my photos… *sigh*

Photos that didn't upload correctly before.

I have a circuit that uses an LM317 to source a constant 20mA signal. I keep researching if there’s a better option, but any circuit that’s more accurate is far more expensive and/or takes up a lot more board space. The LM317 just works obnoxiously well.

It’ll probably come down to prosecutorial / police discretion even more than it currently does. It’s not like committing petty crimes is particularly hidden right now (see: driving). Might just be “yeah we have the evidence but who cares?”

I mean, might be the least hassle method of summoning someone to help you up.

1/4w. YOLO.

(In all seriousness, I would probably use 2x the required rating unless I was space constrained. Then I would probably test some from the batch first to see how hot they got.)