This circuit with 117 V output was found in a 1969 Electronic Design. Drive transistors admit equivalents and information about transformers is not given.
This VCO makes use of components from the 1980s. The circuit can be implemented with modern...
This circuit uses an LDR as a sensor to trigger an LED indicator at a preset lighting level. The...
This circuit was found in a 1968 General Electric documentation. It has an input impedance of 2 M ohms...