Found in an 1989 R-E Experimenters Handbook, this circuit produces several sound effects that can be modified. The signal must be applied to an external amplifier.
This circuit drives symmetrical loads through a single transistor. The circuit is from a Radio...
The transistors of this circuit can be BC548 for NPN and BD136 for PNP with load up to 500 mA. The...
circuit is used to increase the sensivity of a relay. A 50 to 100 mA relay can be triggered with...