This circuit converts a high voltage into a frequency using an optical coupler. The transistor can be 2N2646 and the coupler admits equivalent. The circuit is from a 1974 publication.
In the figure we have the way to connect several 555 to obtain sequential operation. The component...
This circuit was found in an 80's General Electric documentation. The circuit uses uncommon...
This modulator can be used in a data link or other signals up to 200 kHz. Range can be achieced...