Found in Ferranti's 1969 documentation, this circuit can be mounted with a modern equivalent transistor. The circuit has a 4 V immunity and can be used as a shield for sensors.
This interesting circuit of an ancient American publication makes the pattern of an exclamation mark...
This switched amplifier or PWM was obtained from a 1972 RCA technical documentation, using...
I found this circuit in an English magazine from July 1982. The circuit is still viable because all...