Free Circuit Diagram

We  can make a simple touch switch using only two inverter gates, two resistors, and two capacitors. The schematic diagram of the circuit is shown in the figure below. At power up, the output (of U1A) will be high, and the inverting output will be low because U1A gate will be triggered to ground level [...]

Pulse width modulator produce a PWM signal, a pulse with a constant frequency but with the duty cycle vary according to a modulating signal. Here is the schematic diagram of pulse width modulator circuit using 555 IC as the active component: This pulse width modulator circuit need external pulse train input to trigger [...]

In this video tutorial,  you can learn how to make a LED flasher circuit using 555 IC. The project uses a breadboard, so you don’t need any soldering work. A good start for do it yourself  (DIY) project. [Video tutorial source: Youtube.Com]

Sawtooth wave oscillator  circuit can be implemented using several methods, here we present one design that employs 555 IC.  Here is the schematic diagram of the circuit: The core of the circuit uses  general 555 oscillator configuration, but instead of using a fixed resistor to limit the current for charging the capacitor, we [...]

This audio frequency meter uses 555 IC as a monostable multivibrator (one-shoot trigger). A monostable multivibrator can act as a frequency-to-voltage converter because it produce a fixed pulse width, with the repetition rate/density is proportional to the triggering input frequency. Here is the circuit’s schematic diagram: For resistor R1, because it set the [...]

This 555 circuit will activate a buzzer and turn on a LED lamp when you touch the probe. Here is the circuit’s schematic diagram: lf you touch the plates, the lamp and the buzzer will be activated for a predetermined time period. The time period is determined by 100k resistor and the 10uF [...]