This 6-transistor Japanese commercial radio was manufactured in the 1960s. The receiver is a super heterodyne type with germanium transistors and is powered by a 9 V voltage.
This circuit activates a relay when raindrops fall on the sensor. The circuit is from 1960...
Instead of the lamps, LEDs can be used in series with 470 ohm resistors. The circuit is from an...
This circuit is quite simple to assemble, having been found in a traditional American publication. The...