With this circuit it is possible to modulate pulses from a pulsating input signal. The PNP transistor can be the BC558 and the power must be supplied with 5 V.
The circuit shown in the figure consists of an amplifier for stereo sources with Maxim's MAX9723...
This simple low current circuit was found in a Radio Electronics magazine from August 1960. The...
This small 2-transistor amplifier was found in the Radio Electronics magazine of May 1959. The...