In the figure we have the way to use the transistors of an old-paired pair as a trigger circuit. The circuit is by Philips from an old documentation.
This circuit was found in the Electronics Experimenter Handbook from 1991. The sensor is a diode...
This circuit can be used on audio, video, or data links to receive modulated infrared signals. The gain is...
With this circuit it is possible to obtain a voltage modulated in amplitude with a maximum current of...