LED forward voltage drop with temperature

John Larkin wrote in news: snipped-for-privacy@4ax.com:

unprofessional, immature self... again.

You are always stupid, and always childish. Just like Trump.

nickel, tin, iron, platinum, mild steel, lead plus some alloys ALL have th e same positive tempco of resistance.

Don't be too much of a jerk.

Explaining the conductivity of metals was one of the first successes of quantum mechanics. I think the classical prediction for metal conductivity is off by a factor of ~100. (Why don't the electrons scatter more in a metal?)

George H.

Never to sensible people.

The people who don't regard John Larkin as a jerk have to be insensible peo ple - insensitive to his egomania and fatuous point scoring.

John Larkin's idea of "sensible" is much the same as his idea of "correct"

- something or somebody he agrees with.

John Larkin is a Sub Human Moron

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Look who just did.

That certainly IS an interesting question. It's approximately zero. The electrons in a superconductor do not share heat with the lattice because they've become decoupled: the superconducting transition turns thermal conductivity off, and is a useful thermal switch.

Mobile electrons carry heat, but not mobile Cooper pairs of electrons.

Am 22.04.2020 um 17:55 schrieb John S:

Hello John,

You can adjust the temperature coefficient with the parameter EG in the diode's SPICE model. Eg is 1.11 by default. Simply change this number a little bit until you get the temperature coefficient you need.

Examples: .model LED_GREEN D(Is=8.2e-25 N=1.46 Rs=5.1 Eg=2.23) .model LED_RED D(Is=2.4e-20 N=1.655 Rs=1.5 Eg=2.17)

Regards, Helmut

But one would have to carefully measure various real LEDs that are candidates, then tweak the Spice model to match each one. It's a lot easier to just try it.

Does Spice account for the temperature coefficient of Rs?

Thank you, Helmut. This is valuable info for me.