This circuit was found in a Popular Electronics of the 1980s. The microammeter may be the lowest current range of a multimeter. The antenna is telescopic.
According to its author, this device indicates the amount of force applied to the sensors. The...
This is a circuit for testing small lamps and LEDs. The lamps that can be tested are the ones...
We found this circuit in an American documentation from the 60s. The circuit can be made with...