This circuit is from Mullard 1969 documentation. The circuit operates at a relatively high supply voltage and has a 10 Vpp output. The transistors are of the time, but admit equivalents.
The Texas Instruments TIOS101 is a driver that can be connected to both high and low side sensors...
We found this circuit in the National Semiconductor Audio Handbook of 1977. The circuit produces...
When the sensor X1 is opened, the relay is energized. When waiting, the current drained is very...