This circuit was obtained in a 90s 73 magazine for radio amateurs. The power transistor must have a heat sink. The input voltage is 13.6 V.
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...