Path: utzoo!utgpu!attcan!lsuc!ncrcan!brambo!wwg
From: wwg@brambo.UUCP (Warren W. Gay)
Newsgroups: sci.electronics
Subject: Re: Bright LEDs, visible infrared? Colored Chips?
Keywords: Colour, Chips, Larry Lippman, Cats
Message-ID: <435@brambo.UUCP>
Date: 9 Jan 89 15:49:59 GMT
References: <743@optilink.UUCP> <888@ubu.warwick.UUCP> <1590@kodak.UUCP>
Reply-To: wwg@brambo.UUCP (Warren W. Gay)
Organization: Bramalea Software Inc., Bramalea, Ont.
Lines: 36

In article <1590@kodak.UUCP> ornitz@kodak.UUCP (barry ornitz) writes:
>In article <888@ubu.warwick.UUCP> haldane@uk.ac.warwick.cs (Steve Sykes) writes:
>>...maybe light would affect them, but you could do different colours - blue
>>...
>
>Light does affect many chips creating surface charge carriers.  I have even
>seen circuits where the leakage current caused by light in glass encased small
>signal diodes (1N914, 1N4148) caused erratic behavior.  I even saw a RAM chip
>used as the basis for a video camera - someone had cut the top off the ceramic
>package and discovered the effect by accident.  The results were crude with
>essentially infinite contrast (black or white, no gray) and poor light sensi-
>tivity but it did work.
>...

When I was much younger (IBM-1130 days :-), I used to take apart the replaced
circuit boards from the "1130", and take the metal sheilds off the top of the
square "integrated" circuit "chips". The "integrated" circuits of that era
were big enuf that you didn't need a microscope to figure out the chip 
design... and I used to try to get them to work - with the covers off!  
I realized a few years later why I could never get the suckers to work, 
when I started to play with light sensitive transistors :-)!

I don't hug my cats...
	Three is too many to hug...
		I kick them, its more conveniant! :-)


73s de VE3WWG (Warren)..............LSI represents Large Scale Investment,
.................transistors are "discrete", but tubes are just plain fun.
................Bramalea Software Systems Inc...!utgpu!telly \ !brambo!wwg
...................!{uunet!mnetor, watmath!utai}!lsuc!ncrcan /
-- 
73s de VE3WWG (Warren)..............LSI represents Large Scale Investment,
.................transistors are "discrete", but tubes are just plain fun.
................Bramalea Software Systems Inc...!utgpu!telly \ !brambo!wwg
...................!{uunet!mnetor, watmath!utai}!lsuc!ncrcan /