We found this circuit in an old documentation, but it is still current. General purpose transistors can be used, and the SCR can be the TIC106. The bell is a transducer with an oscillator (buzzer).
Found in National Semiconductor documentation from the 1990s, this circuit employs basic...
This circuit should be placed between a turntable and recorder or playback media from the input to...
Found in a 1964 Electronic Design, this circuit uses transistors from that time. Equivalent...