Acid rain monitor


Posted on Dec 29, 2012

A bridge rectifier and 12-volt regulator powers the MOSFET sensing circuit. The unregulated output of the bridge rectifier operates the drain solenoid via switch SI. The sensor itself is built from two electrodes, one made of copper, the other of lead. In combination with the liquid trapped by the sensor, they form a miniature lead-acid cell whose output is amplified by MOSFET Ql. The maximum output produced by our prototype cell was about 50 µ. MOSFET Ql serves as the fourth leg of a Wheatstone bridge.


Acid rain monitor
Click here to download the full size of the above Circuit.

When acidity causes the sensor to generate a voltage, Ql turns on slightly, so its drain-to-source resistance decreases. That resistance variation causes an imbalance in the bridge, and that imbalance is indicated by meter Ml.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Stepper Motor Encoder Circuit
Solid State Latching Relay Circuit
Light Sensor Circuits
Design a esthetic and energy-conserving acousto-optic controlled lighting lamp of corridor
random generator
guild brian may box
12V Low Cost Car Battery Charger Circuit PCB
Need Help Deciphering Circuit Board Schematic
slave flash trigger
400 Hz SERVO AMPLIFIER
Circuit Audio Stereo power amplifier LM4755 11W with Mute



Top