Two sensors are used in this simple remote-control circuit, one to switch on and one to switch off the relay. The circuit is from 1986 documentation. The transformer has 12 V of secondary.
We found this high gain circuit with the LM381 preamplifier in a Radio Electronics from February 1990....
We can produce pulses controlled through this circuit that can function as a shield if powered by a...
If mounted with SMD components, this transmitter will be so small that it can be installed inside a...