Pessimists know the “rebound effect”: improvement in efficiency leads us to do more of the thing. More illumination for example. This (partially) counteracts the good effects.
What I've done is take a large 2n3055 BJT NPN power transistor, and decap it (it is a large metal-can type). Then I carefully removed any coating from the exposed silicon (it typically has a dab of silicone potting compound on it)....
I once got inspired by this: scoollab.web.cern.ch/diy-particle-detectorIt uses photodiodes instead of BJTs. Advantage is that you can get some which are easy to decap. I did not get it to work :/ but also did not spend so much time. I think what is really important is to properly shield the circuit from electromagnetic radiation, use a battery (low-noise) and also shield the detector from light.
The EDA/CAD vendors generally seem to aggressively kill competing projects. You cannot trust any project as long as it is not open source under a copyleft license (plus does not require contributors to sign contributor license agreements).
The decent PCB tools I know of is KiCAD and eventually LibrePCB, which I never tried.
KiCad. Stay away from closed-source tools. They’ll all try to press out the max amount of money sooner or later. Or get bought and discontinued for eliminating competition.
Hi all! I recently purchased some push-lights for my kitchen from my hardware store, and I stupidly didn’t read the package that said that they shut off after 30 mins. This is super inconvenient in my dark kitchen, and I can’t return them. I figured I might as well tinker with them, and any help would be greatly appreciated....
For the first one: Would be good to know what U1 is exactly. Can you read any number/code on it?
If you are lucky it is simply a ‘switch’ which switches on once you press the button and switches of after 30min. In this case you could add a wire which constantly switches the lights on. Then add a normal mechanical switch to the power supply cables.
If you are unlucky, U1 also regulates the current through the LEDs. Then cannot be easily replaced. Is there anything on the other side?
Second picture: To me looks like Q1 (3400) is an NMOS which connects the LEDs to power. The ‘gate’ is marked yellow. It is the ‘control’ input of the MOSFET. The 4 resistors RD RC RB RA (purple) probably limit the current through the LEDs. If you’re lucky, then an easy hack would be to bypass this transistor: Remove Q1 and connect the red and green marks via a mechanical switch. You’d need to scratch away the white coating until you get copper. Then solder wires there. As a consistency check you could measure the voltage over Q1 (red and green marks). Measure once when the module is plugged in but switched off, and once when the LEDs light up. If you see a voltage while the LEDs are dark, then this would partially confirm my guess. As a test: Before removing Q1 you could also try to bypass Q1 with a resistor (~ one, two kOhm) while the LEDs are off. If you see LEDs now lighting dimm, you know that Q1 is the one switching the LEDs.
Other possibility: It might possible that the timeout is computed with an R-C circuit. for 30min you need a rather large resistor because there can’t be very big transistors. R1 (blue) is the largest one. Experiment could be to remove it and see if timeout is still 30min. Or put another 10k resistor in series and see if the timeout gets shorter.
Wondering: What voltage do you connect to the module? Please be extra careful if you have somewhere mains supply voltage.
I’m currently working on a more complex project that uses double sided assembly (and a weird USB-C connector). To practice these things a little, I ordered some low cost boards to get used to that connector and explore double sided reflow (which seems easier than I expected)....
Nice! Thanks for explanation! I don't have much experience with soldering larger circuits. Usually I'm stuck with a soldering iron and tweezers. Just recently got a used stereo microscope. That already helps a lot. But certain packages like BGA are out of reach this way.
Because of innovations in LED technology, the amount of electricity used for lighting is down drastically (www.bloomberg.com)
Radial resistors... has anybody seen these before? (discuss.tchncs.de)
I have a whole bunch of them. They are possibly a bit older (70s, 80s) judging by other contents of the junk box they are from....
Transistor particle detector not functioning as expected (voltage.vn)
What I've done is take a large 2n3055 BJT NPN power transistor, and decap it (it is a large metal-can type). Then I carefully removed any coating from the exposed silicon (it typically has a dab of silicone potting compound on it)....
deleted_by_moderator
What software do you use for PCB design?
I’m interested in learning how to make a proper PCB rather than perf board with wires all over the place.
Help Bypassing Timer on LED Lights
Hi all! I recently purchased some push-lights for my kitchen from my hardware store, and I stupidly didn’t read the package that said that they shut off after 30 mins. This is super inconvenient in my dark kitchen, and I can’t return them. I figured I might as well tinker with them, and any help would be greatly appreciated....
The first double sided board I made at home :) (lemmy.world)
I’m currently working on a more complex project that uses double sided assembly (and a weird USB-C connector). To practice these things a little, I ordered some low cost boards to get used to that connector and explore double sided reflow (which seems easier than I expected)....