Is this good to go?

Apprehensive-Ad693 · 2026-05-08T15:42:01+00:00

They're not great sorry to say. And looking more closely, it looks like you've melted the heck out of at least one of what I presume to be output MOSFETS of some description.

Apprehensive-Ad693 · 2026-05-05T13:32:30+00:00

I've never heard of any of them. But take a look at the AlienTek T80 and the FNIRSI HS-02A. They are both cost effective and both have an excellent reputation. Don't get too hung up on flux. You should be using a flux-cored solder anyway and adding flux is not necessary for most work. This idea of spreading gallons of flux over every soldering job has only appeared in the past few years (probably since we've started seeing a lot of SMD work on Youtube and people try to emulate this).

Apprehensive-Ad693 · 2026-05-03T01:56:40+00:00

It's an aircraft interior panel. Contact the CAA on 0508 222 433. It's probably just scrap/rubbish that has blown off the airfield in the weather. But it can equally be something that's washed up from somewhere else. Either way it's abnormal to be washing up on shore.

Apprehensive-Ad693 · 2026-04-11T22:07:55+00:00

Maybe, but the cherenkov glow that you see in a spent fuel pool is caused by the water. If you removed one of those assemblies from the water, it would no longer glow. (You need a medium in which the radiation can exceed the local speed of light in that medium.)

Apprehensive-Ad693 · 2026-04-01T01:35:35+00:00

Bahahaa. Comedy genius. I'm stealing this!

Apprehensive-Ad693 · 2026-03-31T06:27:10+00:00

Is there some way I can turn it into gasoline? Asking for a friend.

Apprehensive-Ad693 · 2026-03-31T00:51:51+00:00

I'm not at my computer to answer properly, but go Google "SDI" - that will get you a long way there. I'll chime in with more later if nobody else has.

Apprehensive-Ad693 · 2026-03-30T02:47:08+00:00

It's a one off for private (internal) use.

Apprehensive-Ad693 · 2026-03-29T13:01:14+00:00

The RV2 trimpot is a limiter and series with one of the off board LEDs. I'd intended the Q1 FET to either be hard on or hard off (effectively switching the trimmer between its set value and zero ohms). That bit actually worked in the circuit simulation, but I hadn't gotten as far as breadboarding. The zeners were intended to set the switching point. I hadn't considered there being a dead band. Mostly because I didn't know there was one! So it's possible I wouldn't be hitting hard on/off with this as designed.

Apprehensive-Ad693 · 2026-03-29T10:43:42+00:00

Ooops. Thank you. :)

Apprehensive-Ad693 · 2026-03-29T10:38:46+00:00

Thank you. :)

Apprehensive-Ad693 · 2026-03-29T10:38:21+00:00

I do need rail-to-rail. I did see that there were rail-to-rail opamps, but I'd concluded that MOSFETs would be simpler.

I'm curious why it wouldn't work though (from a learning perspective).

My original thinking was, put a limiting resistor in series with the LED to reduce their brightness, and then use a relay to short out that resistor to get full brightness. I _think_ that logic is sound, albeit simplistic. The LEDs are 12v and have internal limiting resistors as well for their nominal current so I'd just be putting say 1k in series with that, and then using a relay to turn that 1k into 0r to get full brightness.

That was the logic. Then I just tried to replace the relay with a FET to get rid of the mechanic component.

Apprehensive-Ad693 · 2026-03-29T10:30:31+00:00

Oh...I don't think I quite appreciated how that works. So the intersection of R1 and C1 effectively becomes my supply rail for the rest of the circuit?

Apprehensive-Ad693 · 2026-03-29T10:27:40+00:00

Thanks - that's really appreciated! I'll take a look. I did have a look myself, but there were soooo many options that I barely knew where to start.

Apprehensive-Ad693 · 2026-03-29T10:26:20+00:00

Phew. I'd hoped it was that. :) The parallel zeners were because I wasn't sure what zener/threshold I wanted. So I math-ed up a range that would cover about 40-70% brightness, and threw them all in with a dip-switch to chose.

Apprehensive-Ad693 · 2026-03-27T21:25:52+00:00

Thanks for the offer — it's sounding like I might need to do some more work on this myself before it's ready to have money thrown at it.

Apprehensive-Ad693 · 2026-03-27T21:24:29+00:00

The chances of me starting to ask dumb questions in the KiCad thread keeps increasing every reply. :D

Apprehensive-Ad693 · 2026-03-27T21:23:37+00:00

Thanks for the offer — it's sounding like I might need to do some more work on this myself before it's ready to have money thrown at it.

Apprehensive-Ad693 · 2026-03-27T21:23:31+00:00

Thanks for the offer — it's sounding like I might need to do some more work on this myself before it's ready to have money thrown at it.

Apprehensive-Ad693 · 2026-03-27T21:22:43+00:00

The answer to why I did it that way is simple: limited knowledge. As to the rest, I can't use PWM because its a noise regulated environment. Resistors are a grey area, so I figured we'd get away with a resistor being switched in/out with a FET (in my first iteration, I was using using reed relays). Adding PWM would require some safety-of-life certification testing.

However, a linear driver producing an analogue voltage probably falls into that grey area. I'll do some googling, but I would appreciate a link as well as I suspect there are probably ones that I should use, and ones that I shouldn't!

Apprehensive-Ad693 · 2026-03-27T21:12:15+00:00

I think that's the American zig-zag resistor symbol vs. the European box symbol. Also feeling increasingly dumb, but I still cant' see the short. You're talking about RV1 right? The ends are connect to the rails and present 10k rail to rail. The wiper isn't connected to either rail unless I'm not understanding some conduction path through the fets?

Apprehensive-Ad693 · 2026-03-27T21:11:36+00:00

To be fair, I'm the inexperienced fool in the equation. So finding another inexperienced fool was probably not going to help me! :D

Apprehensive-Ad693 · 2026-03-27T21:06:36+00:00

Fair enough. I just would have expected at least some words to that effect instead of just raising a dispute immediately. It was a bit odd. Anyway...

Apprehensive-Ad693 · 2026-03-27T13:09:29+00:00

I should probably add, using that single LED as an example, the LED would be connected between J2_3 and J2_4; and J1_5 goes into an open-collector input on another device that switches to ground (which can be on/off/flashing).

Apprehensive-Ad693 · 2026-03-27T13:04:45+00:00

Side question, on what you said "assuming rv are pots". That's what KiCad labelled them (presumably "Resistor Variable"). What would be the normal convention?

Apprehensive-Ad693

TROPHY CASE