Historical Circuits & Projects

Here is a collection of old things I made around 30 years ago. As I have said on on the about page I thought it would be cool to document them somewhere. Almost all of it is pretty pointless crap when you look at it now but anyway I thought they were brilliant at the time. What kid isn’t fascinated by flashing LED lights?

Here’s some of the circuits I made. I have made a few more but they are nothing more than a few components on a PCB and I have no idea why I made them and for what purpose so I won’t bother mentioning them. These however I do remember especially the college projects. Speaking of which here is my digital electronics coursework project. Can’t remember if this was for an exam or not but I got to use the college’s PCB etching facility. This one was done by hand with permanent marker and etched in acid. This was long before CAD PCB design software and all PCB layouts were done by hand.

Here’s a photo of the back side; you can see the hand drawn PCB traces. I plugged a battery in to it and it still works. Note the ‘bodge’ wire. As far as I can remember this is the only thing I made at college that I was allowed to take home. The UK funded colleges are very tight and wouldn’t allow you to keep a few transistors; they unsoldered them for re-use on some other kid’s project. Tight arses.


I had previously made many more things since I was given that Radio Shack electronics kit back in the 80’s; these things below were made from about 1988 to 1991. Ill try and do a brief description of each thing mainly for my own record as I doubt anyone else would find this interesting.

Top row from left to right we have a dual LED flasher using transistors. OK I didn’t make this one as it was made for my by the Bradford Skillcenter’s electronics lab. Next I have a high voltage generator which pulses a relay on and off and then feeds it into a transformer salvaged from an old TV. The voltages this produces is dangerous, probably lethal. God knows why I made this.

Next, an LED chaser made from 74 series logic. Middle row we have yet another LED chaser, a waveform generator, a 555 timer that pulses an LED on / off (under the LED flasher) a light sensor that turns on an LED when dark, yet another dual LED flasher, this one made on a proper PCB I made at home. I think this was the first ever PCB I made at home.

Last row we have a moisture sensor, the middle thing I have no idea what this is and finally an electronic coin tosser again made on an etched PCB. Yeah this stuff serves no purpose but I still want to keep hold of them. Guess they have some sort of sentimental value.

Some of this next lot is more recent and was made for a purpose. The top row from left to right is all stuff made around the same era as the last lot and features a cool thing that makes a silly noise when plugged in and one circuit that counts in binary and yet another LED chasing light circuit. I have no idea what my obsession with LED’s were đŸ™‚

The bottom row is a touch sensor and in the middle a 50Hz timebase used for a clock circuit until I found that a R/C oscillator circuit is not the best if you want accuracy. The final thing is a basic battery tester made for when I repaired UPS’s. It puts a 2A load on a battery and indicates state of charge on a series of LED’s. Ideal for finding that dud in a string of batteries.

Finally some projects that were put into cases all of which were made from old junk;most of the stuff I had I was given or had removed from scrap boards donated by Bradford Skillcentre and some bloke advertising electronics parts in the local paper. Got loads of cool stuff from him but it all went to the dump years ago unfortunately. This electronic dice cost me nothing; all of it was made from 4000 CMOS logic. I made a circuit that counts from zero to 9 as well which was cased in an old beer pump controller but I’m unable to find that right now.

I do have some test equipment I made but I will put that onto a seperate page.