This circuit is better than the previous one in that the control is isolated by a transformer. The transformer has 110 or 220 V primary and 6.3 to 12 V secondary with 200 to 500 mA current.
We find this circuit in a 1973 technical documentation. Common transistors may be BC548 and FET or...
Alternating taps on the pressure switch or sensor, cause the output to alternate the high and low...
This circuit can be used in alarms, data links or áudio links using IR radiation. The circuit is...