This sensitive 4-tube, battery-powered receiver was found in a 1949 Radio Electronics. The circuitry was wired in crystal earphones.
This high power dimmer uses a unijunction transistor to trigger the triac. The triac is choosen...
This frequency corresponds to musical note C3. Frequency accuracy depends on the accuracy of the...
This transformerless power supply uses an SCR as a regulator. It was found in a Popular...