Free Circuit Diagram

Our reader Andrea (andrea[dot]perugia[-at-]gmail[dot] com) sent his circuit to us, and he creates the circuit for educational intent. The main purpose is to show that you can toggle an output state electronically, although physically you use only a push button switch. Here is what he said about the cicuit : This simple [...]

This circuit is not a voice operated switch (VOX) because this circuit is too dumb to differentiate between musical sound or human voice. This is rather a sound activated than voice activated. One interesting application is to control your disco lighting automatically by the musical sound from high power amplifier, when the music signal is [...]

It would be cool and elegant to a have mechanical sound character for our electronic metronome. This electronic metronome circuit will produce such sound, making your life more fun. Here is schematic diagram of the circuit: The metronome circuit consists of two 555 oscillators. The first oscillator is used to make high frequency [...]

The LM4610 uses DC  signal to control the tone (bass/treble), volume, and balance circuit.   The advantages of using DC control is that you can use a mono potentiometer to control both channel, even you can use a DC signal generated from a DAC, so you can control the sound using microcontroller or microprocessor. This circuit [...]

This circuit is similar with our previous dimmer circuit, but the gate control is full-wave rectified using diode bridge. This circuit can be used to replace electric switch for your incandescent lamp, brushed motor, soldering iron or heater. Here is the schematic diagram of the dimmer switch: Please note that his dimmer switch [...]

Feedback in public address amplifier is something that should be avoided. The ideal solution is by adjusting the microphone and the speaker position, but it’s not always possible in many situation. Using frequency shifter to change the output frequency 10Hz lower than the input frequency can solve the problem, but it’s too expensive for [...]