Forty Years On

Roughly forty years ago, in 1971 I left work and went to University to take a degree. (In those days it was worth having a degree, only five percent of the population had them, and you could get a small grant as well). I maintained my links with the electronics industry and was delighted to get a packet from Texas Instruments offering me a free red LED to try.

This was the point that LEDS passed from esoteric specialist items to a commodity product. I recall my amazement when I connected a battery and it lit up. It didn't get hot, it didn't have a filament to break and it took hardly any current.

What an amazing invention.



Of course the only colour commercially available was red, and so it remained for some years. Slowly orange, amber and green appeared and LEDS became mainstream. They revolutionised electronics with their low power and long life. You could now build indicators into equipment without any thought of how the "bulb" would be replaced when its filament went.

I put red LEDs in all my projects, even when they were not strictly required. However, blue or even white LED remained an impossible dream, and as for intensity, well you could never describe LEDs as bright.

So, here we are in the brave new world. The road at the end of our housing estate has suddenly sprouted a single LED powered street light. Suddenly all the Sodium lights look old fashioned. 

Imagine! A white LED outdoor light that is bright enough to illuminate the pavement. How times change.

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