This circuit generates quadrature signals, that is, with a 90-degree phase difference. The circuit must be powered by a symmetrical source and the frequency depends on the capacitors.
This circuit was taken from the 1960's Mullard Transistor Manual. Information about the coils is...
This bridge circuit is designed for 8-ohm speakers delivering a few watts of power. The circuit is from...
This alarm, from a 1996 magazine, can be fitted with two BC548s in the original configuration...