In the figure we have the circuit of a simple humidity sensor with the 4011. The circuit was found in the Radio Electronics magazine of January 1981. It is convenient to place 1 k limiting resistors in series with the LEDs.

In the figure we have the circuit of a simple humidity sensor with the 4011. The circuit was found in the Radio Electronics magazine of January 1981. It is convenient to place 1 k limiting resistors in series with the LEDs.
