This circuit triggers a small water pump when the humidity detected by the sensor is reduced in a flower bed or potted plant. The circuit must use a source according to the driven water pump.
We found this circuit with an operational transconductance amplifier in the Motorola Linear...
We found this circuit in the 1994 Linear Applications Handbook by National Semiconductor. The...
In the figure we have a differentiator with the LM3900 transconductance amplifier. The circuit is...