The setting of this power supply is only 0.1%. We found it in a 1969 US documentation. Transistors may be current equivalents. Note the use of symmetrical power supply.
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...