This circuit was found in a 1970 US publication. Transistors are still common and the circuit can be used as a PWM shield or pulse transmission modulator.
This circuit was found in old documentation but uses components that are still common. The circuit...
I got this circuit from an English magazine from 1977. It can still be easily assembled, as the...
This calibrated circuit was found in documentation from the 1980s. It makes use of an integrated circuit...