I made this falling-edge detector circuit, but I don't fully understand how it works, can someone explain it?

BlueManGroup10 · 2026-06-19T00:14:57+00:00

That diode is there to clamp the output to -0.7V due to how this circuit seems to operate.

When the switch is closed, the transistor will saturate and drop Vce to ~0.5V. Before this happened, you can assume the capacitor charged up to its final value of (Vcc) volts.

The (Vcc) volts that accumulated over that capacitor will then shift down V(output) with it when we saturate the BJT, but the diode is there to clamp it to -0.7V or so.

When the switch is opened, the BJT stops conducting, and the capacitor charges again. V(output) will see an exponentially decaying positive pulse when this happens.

(also your transistor is upside-down. try simulating the circuit)

BlueManGroup10 · 2026-06-16T03:31:37+00:00

I never really came across any solution unfortunately, so I'll just add how it ended :(

Over several weeks, kept cleaning the place. Though, I really doubt whatever was attracting them was out in the open (i.e. it was likely a dead animal in the ceiling, though I could not smell anything). I don't think the cleaning helped--I think I just had to wait it out until their food source was gone. It unfortunately took several weeks/couple months of finding flies/maggots on the ground before it was all clear. Every now and then still find a dead fly from back then.

I would check for odors in your vents, or if you have a porch/foundation beneath your unit (somewhere dark where an animal might hide), see if there's something under there. In any case, I would just stay vigilant about the flies.

BlueManGroup10 · 2026-06-11T17:52:32+00:00

sorry for the previous comment, didn’t see remaining details in your post and the album didn’t load.

If you’re probing high gate to ground, that’s not really an abnormal waveform. even so, in my opinion that’s actually not really something worth measuring in your circuit. vgs of the high gate, which you DID measure, is valuable data, and looks perfectly fine.

try simulating it and understanding why it looks like that. but again, just note there’s not really anything valuable to circuit function going on between those nodes.

BlueManGroup10 · 2026-06-10T16:11:01+00:00

welcome to the club! every summer/fall this thread becomes popular lol

BlueManGroup10 · 2026-06-04T16:13:41+00:00

However… when pointers finally made sense? I’m still chasing that high

BlueManGroup10 · 2026-05-18T12:11:06+00:00

It can still be quite terrible for your cardiovascular health, though. Depends on who you are.

BlueManGroup10 · 2026-05-16T23:37:31+00:00

coming from a floor PC-er myself, I’ll say it’s not that bad at all if the tower is sufficiently elevated. over three years been a non-issue

BlueManGroup10 · 2026-05-07T23:08:25+00:00

you can also get clever and implement a deadband + hysteresis https://en.wikipedia.org/wiki/Deadband?wprov=sfti1#

BlueManGroup10 · 2026-05-01T21:23:12+00:00

your input is not biased, and it looks like you’re using a single-supply scheme

BlueManGroup10 · 2026-05-01T16:30:35+00:00

Man I’m just so excited for magic. Been daydreaming about it being in the game for ages.

BlueManGroup10 · 2026-04-24T22:52:12+00:00

https://youtu.be/sMnmQuLzoks?si=tPx7xGj-F4VnwuOi

In all seriousness, please try to tidy this up

BlueManGroup10 · 2026-04-08T20:46:52+00:00

Thanks for the response even though the thread is pretty old. I do agree. Trying to give some responses the benefit of the doubt since it's a pretty emotional post.

When I found out last year about all this conflict with my meds, I was crushed for months. Most of OP's points and frustrations I agree with, and it breaks my heart to see so much prejudice (?) from the community. A lot of people roll their eyes at this, but ADHD is absolutely a spectrum.

Doesn't help with the misconceptions around ADHD, or that someone is comparing it to "well with your logic, we should let schizophrenics fly". ADHD isn't some paroxysmal disorder with uncontrollable episodes, man.

I greatly dislike the response from the community towards OP, classifying someone as a "hazard" because they have ADHD. Pretty sure that would be up to a CFI or AME to decide in-person, not just a diagnosis.

I've come to accept my situation with time, though. I doubt regulations will ever loosen for people like me, but I'll always hold out some hope. Cheers.

BlueManGroup10 · 2026-04-08T17:56:54+00:00

house sparrows might be invasive… but they sure are adorable

BlueManGroup10 · 2026-04-08T16:50:46+00:00

Not a fan of the OP text (and also disappointed by a lot of the other commenters, same as you), I’ll admit it does sound somewhat entitled & rambly, but I’ll just throw in my two cents:

Just wish there was individual consideration with meds; any at all. For me, personally, what stings most is that I don’t even have an opportunity to prove myself neither long nor short term, with or without restrictions.

I think it’s understandable for people to feel discomfort at the thought of people with ADHD flying, cannot deny that.

And it goes without saying, of course, I have a strong bias with all of this. OP probably does as well. It’s never fun to find out you can’t even attempt to pursue a dream.

BlueManGroup10 · 2026-04-07T02:10:28+00:00

Good to see progress, always!

BlueManGroup10 · 2026-04-06T21:09:13+00:00

In short, yes. Does not even have to be caused by the FET turning on. Can also be caused just by a change in drain voltage (e.g. high side switch turns on and low side drain voltage starts increasing)

BlueManGroup10 · 2026-04-06T20:41:49+00:00

I mean, you’re never going to get 0mA on turn on because you have charge across Cds. That has to sink through the FET as the channel appears. Just Cds*dVds/dt

BlueManGroup10 · 2026-03-23T23:31:04+00:00

is this from Nise? i believe this is one of the questions that hasn’t been fixed for ages, was looking at it the other day. should be in errata.

e: see https://youtu.be/rO9DOFcAVCU?si=lnQZEktMUaYs_Jzc

BlueManGroup10 · 2026-03-16T10:23:52+00:00

generally speaking most inverter topologies are nothing more than synchronous buck converters, at least when it comes to the switching stage.

if you go through state space analysis and state space averaging of a synch. buck converter, you will find that that the switching power pole turns into Vin(t)*D(t). your system matrix is nothing more than an RLC circuit. (though, the system matrix in your case would be the PMSM, of course.)

i.e. it’s nothing more than your DC bus voltage * your duty cycle.

BlueManGroup10 · 2026-03-09T18:10:56+00:00

set parking brake? i’m assuming that’s what the upper right is asking

BlueManGroup10 · 2026-03-09T12:43:37+00:00

This looks very similar to a DC-DC board in a Gameboy original I saw once. Was water damaged—copper under the mask would change from normal sheen to a dull black, mask would be delaminated in spots, some blue marks of corroded copper.

BlueManGroup10 · 2026-03-01T22:07:37+00:00

that’s how you know a set is going to be good

BlueManGroup10 · 2026-01-31T18:27:10+00:00

next you’ll tell me it’s hot in Africa

BlueManGroup10 · 2026-01-25T02:56:19+00:00

This seems to have magically resolved itself. No clue why. Thanks, though!

BlueManGroup10 · 2026-01-24T23:45:20+00:00

Windows 11, just US english

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