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 figure shows how to control the blinking of a 5 V blinking LED with an LDR. The LED only...
Suggested by Maxim in documentation from the 90s, this circuit has its response curve given next to...
This circuit is from a 1965 General Electric publication. It uses a thermistor to fire a reed...