Two-tone solar buzzer (CB20493E)

This circuit was found in a 1991 publication. The transistor can be a general-purpose type.

1-Transistor MW Radio (CB11576E)
This experimental AM radio circuit was found in a 1979 English magazine. It can be fitted with a...
Two-LED Flasher 1 (CB20422E)
This is a variation of the two previous circuits but controlling two LEDs. The brightness of the...
15-Channel Remote Control Receiver (CB13998E)
This circuit is the receiver for the CB13997E. The transistor can be the BC548. We also found this...