Re: Blue LED Dial Lights. (Or other colors)
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Ya know....? Come to think of it...? I shudda remembered that.
Thanks ? ?73 KW1B
From: "Dale Parfitt" <PARINC1@...> To: [email protected]Sent: Saturday, October 1, 2022 3:34:17 PM Subject: Re: [HallicraftersRadios] Blue LED Dial Lights. (Or other colors)
The bayonet LED¡¯s have a built in? current limiting resistor- depending on voltage and color, 470 Ohms is a common value. ? Dale W4OP ? ? I assume that LED's are much like transistors and other SS devices.? Open transistors almost always started as shorted transistors but the very fine wires that connect the silicon wafers to the leads will burn out immediately with a short even with very little current available.? It is almost like a microamp fuse.? I would expect that a shorted LED would burn open long before the transformer would feel it.? Just my opinion. Jerry On 10/1/2022 9:47 AM, William Barrett, KW1B via groups.io wrote: Ya know,? I saw those advertised somewhere a while back and a guy who?I resepct for his technical savvy?said they were a bad idea. His thesis was that LEDs occasionally go bad in a "short" mode, unlike conventional bulbs that virtually always blow "open."? He said a shorted LED could burn out the filiment winding on the power transformer.? Sounded kinda hyper-picky to me; I never saw a LED fail in?dead short mode, myself.? (..and I bin doin' this for If not, I have number of things I'd like color LEDs for the dials (I sold the Drakes a while back, but the point remains.)
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