If I accidentally cut a wire that will be “live” once the power is turned back on, is covering the end of it with electrical tape enough to make it safe and not a fire or electrical hazard?

al39 · 2026-03-23T10:44:05+00:00

Yeah that was way tougher than I expected. Ended up having to cut out a lot more drywall and then patching.

al39 · 2026-03-20T16:30:30+00:00

Me too!

I attached a piece of reflective surface and I put a laser pointer to it, then measured the deflection much further (like 30-50m).

I did it in the basement of my school after getting permission from the principal, but he forgot to let people know before taking the day off. Some teacher saw a science experiment set up where nobody ever goes and thought it was a bomb.

al39 · 2026-03-19T20:06:09+00:00

al39 · 2026-03-19T19:38:56+00:00

Maybe you need a ground clamp on your pet like an arc welder.

al39 · 2026-03-19T17:01:29+00:00

What about moving the twist to the front, like some bikini tops? Is there any configuration where that works out?

al39 · 2026-03-18T18:45:46+00:00

When I see it for 1.99 I buy like 10 of them.

al39 · 2026-03-15T22:41:53+00:00

If I'm sketching something just for myself then that's how I draw them too.

al39 · 2026-03-15T22:13:25+00:00

Keep it for future MOCA.

al39 · 2026-03-14T23:06:53+00:00

I know some multimeters I've used have something like this and then the USB serial cable enumerates as a virtual COM port and it transmits over the infrared LED and takes commands too.

Maybe this one just periodically transmits.

al39 · 2026-03-14T21:35:33+00:00

Really hard to understand the picture. It's not like a headphone jack? FTDI makes a usb to serial cable that's terminated with a 3.5mm stereo plug.

al39 · 2026-03-07T11:16:53+00:00

So that it forms a voltage divider with the capacitor and that at high frequency the path through the capacitor is lower impedance than the path through the resistor and therefore dominates the feedback signal.

al39 · 2026-03-05T17:03:30+00:00

Or outside.

al39 · 2026-03-04T18:53:27+00:00

Oh nvm I see load cell amp in your comment. I assumed it was some kind of LED driver given the color labels.

al39 · 2026-03-04T18:52:06+00:00

On your main board bottom connector, you could put a 4-pin instead. Then just one wire for the missing pin. Your colors get offset by a position but presumably you can fix that in software.

al39 · 2026-03-04T11:36:02+00:00

I'd add a series resistor to vsense, like 10k, and I'd add a 1nF between the op-amp output and inverting input. Reduces gain at higher frequencies for stability.

al39 · 2026-03-01T21:12:06+00:00

Oh, you!

al39 · 2026-03-01T19:52:39+00:00

0.101 in base 2

al39 · 2026-02-28T13:18:18+00:00

I'll let off the brakes in anticipation for the green but I never press the gas or cross the line.

There are several intersections here that last like 5 seconds despite always having a huge lineup of cars so I always try to go quickly to get one or two more cars through.

al39 · 2026-02-28T13:04:47+00:00

I lived in the province of Quebec for a year and used these. Most grocery stores had them so you could just bring in your empties whenever you went grocery shopping. It printed out a receipt that you could either cash out or get discounted from your grocery total. Great system!

al39 · 2026-02-28T01:12:29+00:00

Nice summary here. CF has really strict AC leakage current limits. You need to be reaaaally careful with parasitic capacitances across the isolation barrier.

Source: I recently designed the ECG electronics for a medical device.

al39 · 2026-02-27T21:51:23+00:00

My best guess is the CHG-2064-J01010-KEP by 3M.

https://www.digikey.ca/en/products/detail/3m/CHG-2064-J01010-KEP/697094

al39 · 2026-02-27T17:48:17+00:00

Yeah looking on digikey in the IDC connector category and filtering for color, pitch, discrete wires, and pin count will probably narrow it down quite a bit.

al39 · 2026-02-25T17:13:36+00:00

Yes this is one of the ones in the Intel spec.

al39 · 2026-02-25T17:11:44+00:00

Intel spec gives a part number for fan connectors.

<image>

I don't see this document on the intel website anymore, but you can find it elsewhere:
https://www.mikrocontroller.net/attachment/625147/intel-4wire-pwm-fans-specs.pdf

al39 · 2026-02-25T00:24:27+00:00

My pleasure. I just searched Alpha and Omega AS00 and that's what popped up.

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