My exploits in electronics
I have been interested in electronics since the age of about 10 when I built my first crystal set. Hearing Radio 1 (which was all I could get), without even a battery connected was pretty impressive at that age.
Some of my later projects include:
Stuff I keep intending to do...
- A box to emulate an Epson printer and grab the text to a file
- I'm sure there's another one but I can't think of it at the moment
More details on these projects in the future (if there's any demand!)
This was something I built based on a circuit that appeared in Everyday Electronics (I think).
Of course since working in the automotive industry, I realise how far short of 'real' automotive electronics it fell! It did have a reverse-battery protection diode, and it ought to have had some form
I constructed this while I was at university (BEng, Communication and Control Engineering at UMIST if you're interested). I got hacked off with walking all the way across my huge student bedroom to turn my stereo on and off, so I knocked up a circuit which would toggle a relay with each pulse from an IR transmitter. The receiver was a little bit too sensitive to electromagnetic interference (EMI) and would trigger randomly at times. (Van Halen's "jump" at high volume at 5:30am is not a pleasant wake-up call!)
This was when I learned that trying to fix EMC problems after the design is built and boxed is not a good plan! Lining the box with kitchen foil and fitting serious 'motor-noise-suppressors' helped things for a few years.
Then one day, it went into oscillation. The relay clicked rapidly until the fuses protecting the supplies to my HiFi went pop :-( After this I meant to redesign and rebuild it - then I got a new amp, which has a remote control and a switched mains output on the back. Can't see me getting around to that redesign now!
This was an entertaining project until I got to the hard optical bit!
I gutted an old dot matrix printer and knocked up an interface board which connected the LPT port of my PC to the stepper motor drivers in the printer. I could drive the head back and forth and feed paper up and down with these.
An LED for illumination and a phototransistor on the print-head - the latter connected to an analogue to digital convertor (ADC), which I wired to the input side of the LPT port finished the hardware.
I had a crude scanner! I could have done with a lens arrangement in front of the detector, but in principle it worked! The registration between passes of the head in opposite directions was fairly appalling.
Scanners are cheap enough now to dissuade me from further experimentation, especially as I've done the 'fun' bit of the hardware and software. Optics have never been my favourite task!
My GCSE project at school. Very basic 555 timer circuit which would turn the enlarger on and off in my dad's darkroom. It worked well, producing consistent exposures, but I can't believe they let me build a project with the mains connected to it and then box it in a piece of bent perspex with the back Velcro'd on!
I have an old Amstrad CPC6128, and a bunch of documents created on it on disk still. As it's a wacky format disk, the best way I can think of (without paying someone else to do it, which is cheating!) is to print the file to a PC. Some interface electronics would be required to latch the data and then holf off the Amstrad until the PC has dealt with the character. With enough knowledge of the old Epson control codes, I reckon i could produce a decent RTF output retaining some, if not all, of the programming. I drew up some schematics of how it might work, but never attempted to build it. Typical really.
Update at 2006 - I haven't got the Amstrad anymore, but I have the disks, so I now have to get hold of an old drive off Ebay and interface it to the PC somehow...
Tell me stuff