Reddit:Electronics

Last year at a social get-together, I got immensely bored and heard a fire truck siren in the distance. I began brainstorming ways to model the ramping-up and ramping-down of the Q-siren and came up with this simple VCO design and a large capacitor. Like the physical sirens, the circuit has a power button (to ramp up the frequency) and a brake button (to quickly reduce the frequency.

A fun side effect of the way I designed the controls is that when both buttons are depressed, the steady state frequency falls somewhere lower than it otherwise would, which mimics what would probably happen if you tried accelerating the turbine while the brake was engaged. (I have never heard this actually happen, but it’s a fun thought.)

I’m sad that I’m not allowed to post a video on here, but if someone asks for one I’ll figure out a way to share it.

The temperature sensor of the heating station gave up and now it heats up indefinitely. Perfect for making your PCBs very crispy and crunchy.

I am offered a huge lot of electronic components from a former TV repair shop that was active from 1973 - 2015. Resistors, capacitors, transistors, IC's and many other components. HV transformers (TV), switches, knobs, inductors, subassemblies, ... Most of it is sorted in over 40 Raaco bins, and the rest is partially sorted/unsorted. They are asking 400 euro and I have to decide tomorrow by noon. I think I will buy it, but it will take time to move it all and sort it again.

Black thermoset resin packaging is probably far superior from an industrial standpoint, but I’m in love with the beauty of white ceramic IC packages from around the 1970s.

This is in response to "light them up" from mr. blueball. Finally figured out how to light it up with a AA battery. These are RED led's. Please forgive me for any sacred electronic transgressions I may have committed in making this picture, I did not intend to harm or decrease the value of these amazing objects, I am a biologist dammit, not an engineer. In 1972, I visited my father's lab. After turning off the lights, he started turning on rows and rows of red, green and yellow LED's. It was an amazing sight. Thank you to all commentors for the great information and feedback on my first post titled: Interesting old Monsanto LED's 1972.

Nothing I'm just excited

It can deliver upto 12.5 watts (across both the channels) when it is powered with 16v Dc.Means it can run two speaker on 6.25watts (6.25 × 2).

I made this film capacitor yesterday with 2 ~4m nickel strips I had laying around (0.1mm x 11mm) with kapton tape as the dielectric. I wrapped it around a screw to form the shape and wrapped electrical tape around the outermost coil. Then I hot glued the uncovered coils to keep everything in place. I took the screw out and filled the void left behind with hot glue. The capacitor now measures around 27.5nF. I've been having trouble measuring held voltage with a DMM and oscilloscope. I think that's due to the inherent load the voltmeter and oscilloscope add. Nonetheless, my TC1 and my Kaiweets DMM both calculate around the same capacitance.

This isn't really useful to me, but the nickel strip I had lying around was even less so, so I think this is a cool trinket.

It’s still a mess; I just reappropriated the mess to my desk for sorting later. But yeah, this environment wasn’t fit for doing anything. And it showed in the quality of my work work (permanent work from home employee) as well as the projects that I had lined up on this desk. Now at least my bench is somewhat tidy, I actually figured out the issue of this HP frequency counter

My cute lil workshop/man-cave/study room.

My little lovely ZK-DPL has arrived.

It is adjustable DC-DC buck-boost power supply module featuring a digital display for output voltage/current, multiple input options (USB, Micro-USB, pads), and designed for stepping voltages up or down (e.g., 5V to 3.3V, 9V, 12V, 24V) at 3W max output.

working aruond to find some cool things to do with it :)

This button has been working intermittently. I pulled it out and noticed it was less "clicky" than the others. Had spares on a scrap board. Works perfectly now. The hardest part was getting into that area of the toaster.

I thought it would interesting to share some of my Dad's old LED's from when he used to work at Monsanto in 1971/1972.

Hey folks!
I’ve been playing around with the rosco m68k open-source computer lately and wanted to share some progress.
I’m working on this as part of my personal project SolderDemon, where I’ve been experimenting with DIY retro-computing hardware.

On my boards the official firmware boots cleanly, the memory checks pass, and UART I/O behaves exactly as it should. I’m using the official rosco tools to verify RAM/ROM mapping, decoding, and the overall bring-up process. I also managed to get a small “hello world” running over serial after sorting out the toolchain with their Docker setup.

I’m also tinkering with a 6502 through-hole version — something simple for hands-on exploration of that architecture.

Happy to answer any questions or discuss the bring-up process.