The LED is 50! - Page 1
Forum section: electronics / general

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 10, 2012, 09:34:01 am
content: http://www.bbc.co.uk/news/technology-19886534

author: firewalker
author_rank: Super Contributor
timestamp: October 10, 2012, 09:47:07 am
content: Nice!Alexander.

author: PbFoot
author_rank: Contributor
timestamp: October 10, 2012, 05:56:52 pm
content: Nope. This is a typical Yankee twist on the truth. In actual fact:"Russian Oleg Vladimirovich Losev reported creation of the first LED in 1927".- PbFoot

author: free_electron
author_rank: Super Contributor
timestamp: October 10, 2012, 05:59:37 pm
content: Nope. Lozev sw light emitting from a piece of silicon under pressure of a whisker. this is NOT an LED.

author: ivan747
author_rank: Super Contributor
timestamp: October 10, 2012, 08:20:30 pm
content: Prepare for a 5 page long discussion involving this and most early XX century inventors as well.

author: tom66
author_rank: Super Contributor
timestamp: October 10, 2012, 08:59:16 pm
content: Tesla invented it first!

author: Jeff1946
author_rank: Regular Contributor
timestamp: October 11, 2012, 01:04:40 am
content: Thanks to Shuji Nakamura who persisted for many years to finally produce a reliable high power blue led. Key was figuring out a way to make GaN with fewer defects. Note white leds are blue leds coated with a phosphor that converts most of the blue to lower wavelength light. This really a case where one person deserves all of the credit.As an aside I was in Rio de Janeirio a few months ago and was impressed how white the Christ the Redeamer statue appears at night, kind of like a white dove floating above the city. When I visited it the next day I noticed that there were banks of leds (white I assume) to illuminate it.

author: fmaimon
author_rank: Unknown
timestamp: October 11, 2012, 02:03:30 am
content: Quote from: Jeff1946 on October 11, 2012, 01:04:40 amRGB lights, actually. They change colors for special occasions. It was red yesterday.

author: neotesla
author_rank: Unknown
timestamp: October 11, 2012, 03:35:15 am
content: Quote from: tom66 on October 10, 2012, 08:59:16 pm+1

author: SeanB
author_rank: Super Contributor
timestamp: October 11, 2012, 04:56:17 am
content: I remember the first cheap ultra bright led chips in green. I made a torch out of one, and it was the first led that could project a visible spot in shaded sunlight at 20mA.

author: RCMR
author_rank: Frequent Contributor
timestamp: October 11, 2012, 05:04:58 am
content: I remember my first 7-segment LED, it cost about $30 way back then and instead of having monolithic segments, each segment was made from an array of tiny dots.In 1977 I also had one of those LED watches that had a battery life of about 2 months.And my first calculator (about 1975/6 had *tiny* a little LED display in which each digit had a plastic bubble-like lens over it so that it became big enough to actually read.$40 for a basic 4-function unit.

author: SeanB
author_rank: Super Contributor
timestamp: October 11, 2012, 03:53:23 pm
content: I remember changing from filament displays to LED displays. 7 resistors per digit to put in a 4mm spacer between 2 pcb's and solder, and then solder the 8 wires from the existing display on to this sandwich. 470 ohm 1/8W resistors, and the board took 16 displays, along with a few resistors for some of the decimal points, along with some 3mm as colons. Took about 3 days per board to do and test then fix the errors. Then the complaint of too bright, so i did a little thinking and added 2 1N5403 diodes in the common lead to drop the voltage to the display. Not going to unsolder all those resistors and increase them to 680R, way too much paperwork to do.

author: G7PSK
author_rank: Super Contributor
timestamp: October 12, 2012, 02:44:19 pm
content: LED is electro luminescence this was first created at the Marconi laboratory in 1907 by HJ Round using silicon carbide with a point contact.