02-21-2011, 10:42 PM | #18 |
Nomadic Tribesman
Join Date: Nov 2008
Location: Brampton, Canada
Moto: '09 ER-6n
Posts: 11,150
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It's actually almost the opposite situation, in theory. An incandescent lamp provides low voltage drop, unless it's heated up. It takes a fair bit of current to heat one up enough, that it lights. As it heats up, it has a higher resistance to current flow. That's why incandescent lights usually blow when you first turn them on; low resistance equals high current flow, so they blow like a fuse.
LEDs are a different animal. Once they reach a certain threshold current, they try to force a fixed voltage drop across them. For a basic red electronics LED, that voltage is roughly 1.5 volts. They effectively become a variable resistance in the circuit. "Breakdown voltage" is more of a thing for Zener diodes, which are designed to let current through once they hit a certain voltage. If you hit breakdown on a regular diode, or a LED, then it's usually followed by "burnt chip smell" Leakage current is generally pretty damned low, though it can obviously be significant in some applications. I actually went to school for this crap, though I never use it these days *EDIT* Actually you're right about the 'breakdown voltage' thing. I forgot that they also use the term when talking about both forward AND reverse current.
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"Everything's better with pirates." - Lodge, "Dorkness Rising" http://www.morallyambiguous.net/ Last edited by Papa_Complex; 02-21-2011 at 10:51 PM.. |
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