Free Circuit Diagram

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 [...]

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 [...]

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 [...]

This LED (Light Emitiing Diode) display consist of 10 LEDs to indicate the level of an input signal. If the signal is small, only LED#1 will light, and if the signal level getting higher then you’ll se the light dot will move through LED #2, #3, #4, … and so on. When the signal input [...]

This circuit provide automatic current limiting up to 8.4A. Unlike current limiter that uses only a resistor, this current limiting circuit doesn’t drop the voltage, or at least keep the voltage drop at minimum, until a certain current amount is exceeded. This current amount limit is adjustable from 1.4 A to 8.4A using a [...]

The excellent high input impedance, high slew rate, and high voltage qualities of CA3140 op-amp make it suitable for Wien-bridge sine wave oscillator. The basic circuit for Wien-bridge sine wave oscillator is shown in the figure below (the upper part). You can see the formula in the figure, when R1=R2=R, and C1=C2=C, then the formula [...]