Free Circuit Diagram

Metronome is very important tool if you studying music playing. There are mechanical metronome device in the past, but today, electronic metronome is much more popular since it can be very simple, compact/small, reliable, and also has the most interesting feature: cheap. Here is one example of the electronic metronome schematic: Parts: [...]

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 high durability nature of a light emitting diode (LED) make it suitable for ON/OFF indicator application. Because the limitation on low operating voltage, LEDs are normally applied on low voltage application.  Fortunately, there is a simple method to apply LED indicator for high powerline voltage: reactance of a capacitor can be used to limit [...]

This LED flasher give similar circuit with the previous transistor LED flasher, but this circuit use a 555  integrated circuit chip as the active component. Here is the schematic diagram of the LED flasher circuit: This circuit gives alternating LED flashing, but with different flashing period between LED 1 and LED 2. The [...]

Classic LED Flasher Circuit This LED flasher circuit is a classic two transistor flip flop. This flasher circuit is very popular and it’s usually the first circuit to build when starting electronic circuit building hobby. Here is the schematic diagram of the famous LED flasher circuit: How LED Flasher Circuit Works [...]

LED flasher circuit here will flash a LED using only 1.5 volts  supply voltage. Normally, to make any LED lamp works, you need more than 2 volts power supply. This because LED will work only when the supply voltage is higher than its forward bias voltage, around 2 volts  for red LED, and slightly lower [...]