Found in a 1968 American documentation, this circuit generates 1 kHz signals. The SCR used is not a common component today.
The output voltages of this power source are selected by a switch according to the capacitors. The...
This circuit is from a 90s Popular Electronics. The circuit employs a ZN461E that is not a common...
This circuit was found in Siliconix documentation from the 1980s. Equivalent operational...