Rare Texas Instruments LED WATCH

This is a REAL rarity.....!

Not seen on BOB before!  1970,s

Texas Instruments LED watch in original box and  packing.

The watch has some wear and use  on the bezel and the strap has been changed and replaced.

Fully working original timepiece.

A light emitting diode is a semiconductor diode. The dimensions are from 0.3 to 1 mm. The time is displayed by pushing the crown of the watch. The electrical current will start to flow through the diode and while the electrons stream from the N-area into the P-area, some of these electrons will "fall" into the holes of the P-area. This process is called recombination. The energy which is released this way, will be converted into warmth or light, depending on the composure of the diode. For instance a combination of 40 % gallium phosphide and 60 % gallium arsenide on a gallium arsenide substrate will result in a bright red light. Normally the display will contain four digits of seven segments each. Each segment consists of four or five light emitting diodes. Because the electrical current consumption of these watches ranges from 10 mA, without display, to 10 mA in the dark and 100 mA in full light, the two batteries need to be replaced twice a year.