Found in a 1990s Popular Electronics, this circuit uses two transistors to boost the power of a 741 with audio signals. The power depends on the transistors used, which can be general-purpose types.
This circuit emits an audible signal when the mains voltage ceases. The circuit is from a 1973...
We found this circuit in a 1966 RCA manual. The integrated circuit is unusual, and the Triac must...
Short duration pulses or "clicks" can be generated with the circuit seen in the figure. The...