Then knowing he needed 4 mA to power each LED for backlighting he used some 1978 vintage current limiting diodes designed to pass 2mA each regardless of voltage source, within limits of course.

also known as a Shockley Diode, is a crystal made of alternating layers of N- and P- type semiconductors. By putting in four layers, instead of the three used in transistors, the Shockley Diode ...

The semiconductor light-emitting diode, or LED, is a key component of today's technology. Modern households have numerous tiny glowing indicators — provided by LEDs — that are used for reading ...