DIY - Do It Yourself Projects
Initially, I did not intend to share my work, hence I did not create much documentation. As most of my projects were one-time tasks, I usually only produced a hand-drawn and barely legible diagram, and sometimes, I didn't produce any at all.
Nevertheless, I have made every effort to reconstruct and retrieve the missing information to a degree that an intermediate or experienced hobbyist can complete the projects. Please note that most of the circuits were designed before microprocessors became a cost-effective way of building gadgets. Nonetheless, the circuits can still be useful in construction projects.
The projects I present here are just a small selection of simpler and hobby-friendly electronic circuits that I have designed and built. I may update the list from time to time.
IMPORTANT DISCLAIMER
Please note that not all of the projects come with full instructions or printed circuit board designs. However, all designs have been tested and built, so you can rely on the schematics provided.
It's important to be aware that some designs involve potentially dangerous voltages and/or power levels. I cannot assume responsibility for any injuries or fatalities that may occur if proper handling and precautions are not taken.
All of the circuits presented on this site have been designed by me, unless otherwise stated. I have made every effort to ensure that I am not infringing on any copyrights or patents, and I am not intentionally presenting others' work as my own.
You are welcome to use the information presented here as a guide for your private or non-commercial construction projects. However, please note that this information may not be used for commercial purposes, published, copied, transferred, or distributed without permission.d in any way, without written permission from me.
Electric Motor Speed Controller (ex. for toy cars)
Pulse-width controlled DC-motor power controller with a soft turn of and turn off. Good for any kind of medium power DC-motor that should be started and turned off gradually. Maximum speed can be set - as the direction of rotation. Uses just a few of "plain vanilla" components.
Neumann U47 tube microphone refurbish
This project gives you instructions and hints about constructing a fully working U47 tube microphone from old and/or refurbished parts. The instructions might be helpful also during the repair and restoration of these microphones.
Power supply for U-47 tube microphones (+105VDC)
A highly capable special-purpose power supply for up to 6 Neumann U47 microphones. The power supply is fully regulated, foldback current limited, and can withstand indefinite constant short circuits. Output noise and ripple are very low (<200uVpp), a requirement for hum-less operation. Performance is superior compared to the original power supplies.
An 8-sector electronic fortune wheel simulator with effect lights and sound. Great for pre-school children, schools and bazaars.
Home Intercom Using Existing Old Telephones and Wiring
This clever circuit adds to your old household wired POTS (Plain Old Telephone System) phones an intercom system - without disturbing the normal telephone operation. This design uses only 30 components - including the PSU!
Valentines' Day Animated LED-Heart
4-Band Parametric Audio Equalizer (tone control)
A professional quality 4-band (mono) line-level analog audio sweepable equalizer.
S-Video Chroma Processor
Realistic Traffic Light Simulator
An unorthodox and unique traffic light simulator using only op-amps and comparators! Simulates one car lane and one pedestrian light signal. Can run automatically or be controlled by a pedestrian push button. Controls either small 5mm LEDs or optionally higher power (low voltage) lamps.
60W Ultra-cheap & simple Audio Power Amplifier
The amplifier is very simple but gives a robust performance. The chosen components are a good compromise between performance and cost. The overall performance is actually very good. All used components are simple garden variety types, that can be probably found in your own component junkyard. The amp is designed for 8-ohm loads, in which it can feed 40W continuous power with a distortion level of 0.1% or less. Instructions are only in Finnish.
40W TMOS Audio Power Amplifier
This is a fully functional and well-behaving matchbox size power MOSFET amplifier. It is compact, cheap and efficient, and good-sounding. It also utilizes and introduces a unique "dual-bootstrap" technique, invented by the author in 1984. This simple idea guarantees that the output stage can saturate symmetrically close to both power supply rails. This utilizes all available power supply voltage to provide the highest possible output peak power.
Simple DICE circuits
Throw you dices electronically.
4-channel Effects Dimmer
Throw you dices electronically.
Under Construction