This is a simple flashing led circuit with 2 leds and 2 NPN transistors. It illustrates the behavior of transistors and capacitors and if you use an oscilloscope it will be very easy to determine what ...

In this section we shall discuss the interface between a photosensor and its associated electronics. There are really just two photocell applications – light measurement, and the reception of ...

Once more opto-isolators are to be seen in Wonderland. The aim was to see if the faster photodiode types can operate quickly in common collector mode. They consist of an infra-red led and a fast npn ...