This circuit was found in a Philips documentation from 19678. The transistors are from the period with emphasis on the married pair. Modern equivalents can be used.
The circuit in the figure can be used to trigger a triac or even a comparator in a project that...
The operating range of this circuit ranges from 0.5 to 2 MHz and its gain is 11dB. Transistors can be of...
This simple detector was found in Popular Electronics from the 1990s. Both the phototransistor and the PNP...