Free Circuit Diagram

For any electrically conductive liquid level measurement, this single chip circuit is very compact and simple. This circuit is an ac excited fluid level sensor, which uses alternating current to provide biasing for the sensor probe to avoid electrolysis of the probes.  This ac excitation makes the sensing probe has longer lifetime. This circuit can [...]

Water level controller circuit described here control the water level inside a tank. There two modes available with this water level controller circuit. The first mode is empty mode, when the controller will drain the tank if the water level reach the upper limit, the pump will be used to suck the water from the [...]

Electrolysis process has been the primary cause of your water level detector probes, and you can avoid this by sensing the current by this probe using alternating current. In alternating current, the electrolysis process will be reversed for every alternating cycles, making the probe will last longer to survive from corrosion. The electronic circuit for [...]

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 [...]

To obtain an accurate pressure value, we must remove the offset errors. There are  many basic circuit designs that is used to remove the offset errors. This  circuit uses three method to remove the offsets errors, they are symmetrical offset trim, asymmetrical offset trim and amplifier gain adjustment. Here is the circuit: [...]

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 [...]