Electronic Door Lock Security Key

This is the circuit diagram electronic door lock security key system. It means that this security system circuit is the combination of pressed key itself (not the mechanical). The output can be connected to drive the relay to open the door (usually using motor).

Tube Sound Fuzz Mods

This tube sound fuzz mods circuit is taken from the book of Electronic Projects for Musicians by Craig Andertons. This circuit applies a CD4049 Hex inverter, which consists of six inverting units. Only two are being used in this circuit, so the others are disabled by connecting their inputs to the positive voltage source and… Read More »

Video Amplifier based LH0032

This is schematic diagram of a video amplifier circuit, built based very high speed operational amplifier IC LH0032.

LM4809 105mW Stereo Headphone Amplifier

This is the stereo headphone amplifier circuit diagram, built based LM4809. This circuit can be used for stereo headphone amplifier circuit for home audio system, microphone preamplifier, personal computers and PDA headphone amplifier and more. The LM4809 is known as a stereo audio power amplifier capable of delivering 105mW per channel of continuous average power… Read More »

Stereo Tube Amplifier 4 Watts

This is the circuit diagram of stereo tube amplifier using 6SQ7-GT and 6V6-GT. The tube amplifier circuit is uses the total of 5 power vacuum tube. The diagram is based on the output section design of typical late 1940’s old AM Trutone radio with 6 tubes. The output will be 4 Watts per channel (2x4W… Read More »

Electronic Tachometer

Here is a simple Tachometer schematic. The basis of the frequency converter circuit-current, which converts the input signal into a proportional current measured pointer device. Deflection milliammeter proportion to the frequency input signal. To install the device on input pin A car should be connected to high voltage wire and pin B – to the… Read More »

Solar Powered Mobile Phone Battery Charger

This is the schematic diagram of solar powered mobile phone battery charger. The circuit is designed to charge the battery from a source with a lower voltage. Do not use it to charge the battery with the same or lower voltage than the voltage which is generated by the solar panel. For proper operation of… Read More »

DOD Overdrive Preamp 250

This is the DOD Overdrive 250 preamp circuit diagram. The DOD Overdrive 250 is Yet Another 741 With Two Diodes On The Output channel. It is almost exactly the same as the MXR Distortion Plus, and a number of other units.

Octave Fuzz Pedal – Guitar Effects Unit

Here the circuit diagram of octave fuzz guitar effect pedal. This guitar effect unit is great sounding octave fuzz, with an optional mode of just fuzz. The fuzz is really a absolutely rectified signal and is fairly chewy. For some the Fuzz alone could possibly not be loud enough, this could be fixed by raising… Read More »