While working on high voltage power supplies – several hundred volts – I often found myself needing to discharge capacitors which had retained thier high voltage after power had been […]
A Really Good Notch Filter
When you think notch filter you usually think twin T: In this R1 = R2 and C2 = C3, C1 is 2 * C2 and R3 is R1 / 2. […]
A Tale of Two Noises
There are sometimes when noise is useful. I find that when designing filter for instance that rather than using a swept frequency and an oscilloscope a noise generator and spectrum […]
Short Circuit Tracer MKII
After successfully completing my first quite crude short circuit tracer I decided that I could make a better one: This one will memorise the best result so far and flash […]
Short Circuit Tracer
This is a simple circuit that can track down a short circuit on a PCB or elsewhere to within a few mm or so. The accuracy depends on the parts […]
RC Servo Tester
Having obtained a bunch of RC servos I thought it would be a good idea to test them. One way to do it would be to use an Arduino; which […]
Variable Colour Temperature Lamp – VCTL Mk2
Several years ago I made a lamp for Graham, my artistic brother. This was actually lamp with 2 LEDs; warm – 5300C and Cool – 6300C. Both were 2000lm. They […]
Analogue Function Generator
Every electronics lab needs a function generator! The one describe here, when fully built, produces sine, square and triangle waves at a range of frequencies from about 0.25Hz up to […]
Shed Lighting
When I first built the shed the lighting was provided by work lights on cables hung from hooks in the ceiling. It wasn’t very good. As I mentioned in the […]
Shed – my biggest hack
A couple of years back I decided that I needed a bigger workspace. At the time I was in a room 2.4 x 1.8 metres. I started by looking at […]