Water-level sensing and control

Posted on Apr 27, 2012

The operation of the circuit is based on the difference in the primary impedance of a transformer when its secondary is loaded and when it is open-circuit. The impedance of the primary of Tl and resistor Rl are in series with the load. The triac's gate-control voltage is developed across parallel resistors Rl and R2. When the water level is low, the probe is out of the water and SCR1 is triggered on. It conducts and imposes.a heavy load on transformer Tl's secondary winding. That load is reflected back into the primary, gating triac TR1 on, which energizes the load.

Water-level sensing and control
Click here to download the full size of the above Circuit.

If the load is an electric value in the water-supply line, it will open and remain open until the water rises and touches the probe, which shorts SCRl's gate and cathode, thereby turning off the SCRl, which effectively open-circuits the secondary. The open-circuit condition—when reflected back to the primary winding—removes the triac's trigger signal, thereby turning the water off. The load may range from a water valve, a relay controlling a pump supplying water for irrigation, or a solenoid valve controlling the water level in a garden lily pond.

Leave Comment

characters left:

New Circuits



Popular Circuits

Adaptor for the Dreamcast serial port
Stereo Encoder for FM transmitters
Power supply for 25-watt arc lamp
Sawtooth Converter
TDA0161 Metal Detector
123 Game - All MCU-free
RFI-Free Ringer Generator Works Off Single 5-V Supply
prop clock
GPS reference clock NTP server with Gentoo
Transistor time relay circuit
Low-noise amplifier