This circuit for voltmeter has an output of 1 V for 100 uA having been suggested by American publication of 1969. The transistors are general purpose types.
This 1960s Signalite circuit uses two SCRs to achieve full wave control. The trigger elements are...
This shoot-to-target game uses well-known CMOS circuits and the player hits the LED by squeezing...
This TTL circuit can be used as a shield. The frequency can be changed by changing the capacitors. ...