Archive for category: Power Supply circuits

1.3 Volt Power Source

Power Supply circuits | By: Diagram mania

Circuit : Andy Collinson Email me Description This is a replacement power source for 1.3V mercury cells or other small batteries. It has many uses and I use this circuit in my computer to power a front panel multi adapter which has a digital thermometer. Notes This circuit takes it power from a PC. The […]

Variable Power Supply Using Fixed Regulator

Power Supply circuits | By: Diagram mania

Circuit : David Kwaku Celestin – Ghana, West Africa Email   : mightycelestin@yahoo.co.uk Description This is a similar power supply that I used to power my FM Transmitter. After suffering long problems with mains hum, this design using a pi filtered C-L-C approach. This circuit offers excellent ripple rejection. Parts List: T1 Transformer 10:1 Secondary 24V […]

Fast Electronic Fuse

Power Supply circuits | By: Diagram mania

Circuit :Miroslav Adzic – Serbia & Montenegro Description A fast electronic fuse designed to operate on 230V AC with an adjustable trip current. Notes When the current through the load exceeds a level determined by the position of the wiper on the 1k wire-wound pot, this circuit cuts off the load immediately. If S1 is […]

High Voltage Generator for Geiger Tubes

Power Supply circuits | By: Diagram mania

High Voltage Generator for Geiger Tubes These circuits generate high voltages and can cause dangerous shocks! Do not build these devices unless you are experienced and qualified to work on high voltage devices. The following two circuits are an improvement over the older circuits below. The circuits are shown generating 500 volts but they may […]

Geiger Counter Power Supply

Power Supply circuits | By: Diagram mania

Techlib reader Dave Mouat modified the circuit as shown below:     In the diagram I’ve put the transistor numbers as the ones I’ve used, although you can use standard 2n3904′s etc in these positions without problems as they’re similar spec. The transformer used is a normal audio output transformer, such as an LT700, and […]

Mercury Battery Replacement For Antique Instruments

Power Supply circuits | By: Diagram mania

 I have recently been trying to restore a Radector radiation survey meter, vintage 1950s. This instrument uses a 10 atmosphere argon filled ion chamber as the radiation detector and has an electrometer type vacuum tube sealed inside the chamber. The design is simple and, for the time, quite elegant. Unfortunately it uses three different mercury batteries. One large 1.35V […]

Isolated 9V Supply,Feedback Regulated

Power Supply circuits | By: Diagram mania

  This circuit is my variation on Charles’ floating 9V supply.  My design uses feedback regulation instead of a zener shunt regulator to stabilize the output against battery voltage and load variations.  Replacing the shunt regulator with feedback control makes the supply more efficient for output loads of less than about 500ua.  That might be […]

Balanced Power Supply for Mixed Analog-Digital Circuits

Power Supply circuits | By: Diagram mania

Wall plug transformer low wattage linear power supplies (hereinafter known as WallWarts) are available cheaply ,as surplus, from various online electronics component suppliers. Typical price is $4 to $7 for a 12VDC, 5W part. These make great line isolation and voltage reduction platforms for all sorts of useful power supplies. A $1 three terminal regulator and 3 capacitors […]

Astable Flip-flops

Power Supply circuits | By: Diagram mania

Astable Flip-Flop Circuits The familiar astable flip-flop circuit is a handy configuration for making flashers or generating squarewaves. Here is a typical alternating LED flasher with the LEDs in the emitters instead of collectors as is normally done. (There is another good reason to put them in the emitters – see Karen’s note below. ) […]

Magic Lamp

Power Supply circuits | By: Diagram mania

Magic Lamp You have probably seen "magic lamp" circuits in which an ordinary incandescent bulb is lit by a match. These circuits rely on a hidden temperature or light sensor and are not particularly interesting. I decided to make a magic lamp, too! But, to make it more interesting, I decided to just use plain […]