Using the 4001 integrated circuit, this latching relay can employ any general-purpose transistor. The power supply is according to the relay with voltage up to 12 V.
This circuit activates a relay when raindrops fall on the sensor. The circuit is from 1960...
It can be obtained from Mouser Electronics new superFETs III from Fairchild for voltages of 700 V...
This stage was used in old audio ampliiers and radios from the 1950s and 1960s. It uses one of the...