dapj Web - http://www.dapj.net/
Schematics of delabs - http://schematics.dapj.com/
Diode Reverse Bias Leakage Tester
Voltage Doublers and Multipliers
Making a 74HCT540 LED Controlled Flasher as Annunciator
High Resistance Meter (untested)
Flashing Mains Neon Light Bulb
DIY, Home Built iPod Charger, Build or use at own Risk! - iPod is a valuable asset so i recommend use one from Apple Store
Mains Adapter Converts 230V AC 50 Hz to Rectified DC which replaces a Battery Pack. It was also called Battery Eliminator by older generations as it was used to save Battery Cost in AM Radios.
LED Night lamp, Clock Lamp to see time at night. It is a Green Lamp just 50mA, but its Blue in Color.
Lots if Light on One Watt, yes this works, but should be built by those experienced in High Voltage usage and Knowledge of insulation techniques.
Perpetual Candle - Emergency Light 1W using LEDs, Solar panel can be also integrated. (this circuit is obsolete now) see next or http://san.dapj.com/de-crafts/perpetualcandle
First Revision, Forced to add 3.9E on each LED for current sharing as LEDs were not matched. Not Required if you use One high current single die led.
I fixed a China Torch with New LEDs and a Diode, it failed probably on a drop shock, the battery wire cut ... then when put on charge Few LEDs went bad, as battery was absent in ckt.
Build a DMM or digital multi meter and Small Electronic Testing Tools
555 based Inverter - Doc not complete