A look at some aircraft LED devices.

Airliners (any planes really) have a critical or minimum equipment list that they need in working order before the plane can crank up and head out and the fasten-seat-belt lights are on that list. One crew member will go through the plane and check every single one and if one is burnt out, legally they can't take off. They're not going to risk a late takeoff to solder on one new LED and shake it down when it's designed to be swapped out with just one maaaaybe 2 tools. Above all, fastly getting out.

Dong Strongly

Where in the world are you based, and is it discharged?

Big Clive

It's a big-money industry.

Big Clive

You may be right. It's possible the darlington is being used to soften the turn on by using a resistor to the base with a capacitor so it turns on slowly.

Big Clive

These lights often dim slowly on when you turn them on. Not sure if there's enough circuitry for this. Otherwise the Mosfet is probably reverse polarity protection.

If you want to take some really big aircraft-related things to bits, the contents of Heathrow Terminal 1 are being sold off: <a href="http://cagp.com/events/heathrow-airport-terminal-1/" rel="nofollow noopener" target="_blank">http://cagp.com/events/heathrow-airport-terminal-1/</a> You could get one of those blasted "baggage reclaim carousels". If I could identify the one on which our family luggage appeared, late and smashed, in the summer of 1981 I would very much like to whack it with a big stick. Perhaps, though, the "Electrical control systems (Inc. Inverters and soft start units)" or "100’s of Switch panels and distribution boards" would be more your sort of thing.

Stephen King

You weren't at a British Airways Data Centre recently, were you? :)

Phil Collins

Hey Big Clive! Love your stuff bud! Any chance I could send you a bricked battery bank I got a while back for autopsy?