The selected circuit is from the Texas Instruments optoelectronics manual. With it you can receive optical signals in CW. Transistors support equivalents.
This is the typical circuit of an FET amplifier stage in the common source configuration. The circuit is...
This circuit activates an LED, but it can be modified to activate a relay. The time is set in VR1,...
The circuit shown in the figure activates a small indicator lamp that will start to flash when the...