Found in Philips' 1967 documentation, this circuit makes use of period components. The SCR can be of any type, depending on the power of the controlled load.
This double-beat oscillator was found in American documentation from the 1970s. FETs admit...
This circuit applies to an old dial phone by detecting light pulses in the dial. The circuit is...
This circuit is from 1970 documentation. The SCRs are types of the era that can be replaced with 106...