What is this large heat sink?

bkspero

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bkspero
There is a large black heat sink bolted to the structural member that runs from the firewall to the top of the instrument panel of my plane (see photo). It isn't well attached and I'd like to either get it removed or moved to a more secure spot. Any idea what instrument it is part of, or what it is for? The only instruments that predated my ownership are the Century IIB autopilot, the Garmin 530w, the Edo AM-550 audio panel, the Sigtronics SAS-440 intercom, the altimeter, the turn and bank indicator, the vertical speed indicator, and the clock. I have a copy of the intercom install manual and it does not show such a heat sinked device.
 

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No pulsing landing or taxi lights. Only blinking lights are wingtip and tail strobes, and their wingtip power packs are out near the lights.
 
Any idea what instrument it is part of, or what it is for?
Is there anything attached to it or are there any mount holes on it? Looks like it could be for an old rheostat or transistor set up. Or maybe a dimmer system?

What aircraft?
 
It is riveted to the aluminum structure that you can see behind the heat sink. That is a aluminum angle member about 1 inch in the vertical dimension & 1/2 in in the horizontal, and about 18 inches long. It is located just below the glareshield at the top of the panel, and it ties the top-center of the panel to the firewall of my Grumman Tiger. There are some wires between the heat sink & its mounting bracket, but I can't follow where they go.

The plane does have a panel dimmer, so a good thought. But we're talking maybe 15 watts of lights total. The heat sink in the photo is about 3"x3"x4". Big heat sink for that amount of dimming. And the rheostat is mounted at the bottom of the panel far from this heat sink.
 
I don’t know if this is helpful or not: I don’t think that is a heat sink. It looks like a heat dissipator. It keeps the part at the center of those fins from overheating, rather than preventing heat from elsewhere from overheating the part at the center.

Example: fins on a crank case to help cool the oil within would be a dissipator. A metal barrier between a fuel line and a hot exhaust pipe would be a heat shield.

So what is at the center of those fins?

-Skip
 
What you described as a heat dissipator is what I meant to communicate with the term heat sink. I agree that it is there to dissipate heat generated at the center. Just can't tell what the center is for:(
 
There are some wires between the heat sink & its mounting bracket
Are those wires physically connected to the heatsink? Or come from the heatsink? Does it get warm with power on or after flying?
 
Whatever it is, I’m betting it is antiquated technology and no longer necessary.
 
Are those wires physically connected to the heatsink? Or come from the heatsink? Does it get warm with power on or after flying?
I believe so. They aren't particularly accessible so can't tell for sure.

I rarely touch it, as it's buried under the glareshield. But we have been trying to diagnose some audio issues involving radio transmissions, and the heat sink did not get warm.
 
I don’t know if this is helpful or not: I don’t think that is a heat sink. It looks like a heat dissipator. It keeps the part at the center of those fins from overheating, rather than preventing heat from elsewhere from overheating the part at the center.

Example: fins on a crank case to help cool the oil within would be a dissipator. A metal barrier between a fuel line and a hot exhaust pipe would be a heat shield.

So what is at the center of those fins?

-Skip
It's a heat sink. Whatever is under it gets hot. Heat sinks work by allowing the heat from an object to move away from the component.

 
There is a large black heat sink bolted to the structural member that runs from the firewall to the top of the instrument panel of my plane (see photo). It isn't well attached and I'd like to either get it removed or moved to a more secure spot. Any idea what instrument it is part of, or what it is for? The only instruments that predated my ownership are the Century IIB autopilot, the Garmin 530w, the Edo AM-550 audio panel, the Sigtronics SAS-440 intercom, the altimeter, the turn and bank indicator, the vertical speed indicator, and the clock. I have a copy of the intercom install manual and it does not show such a heat sinked device.
I dunno, but it might help if you tell us what airplane it is in.
 
I'm guessing it was for an old voltage regulator or an old strobe power supply. I don't know what else would require such a large heat sink
 
Remove it and see if anything breaks. Works for software...
 
Remove it and see if anything breaks. Works for software...
Believe it or not, that technique predates software. Back when some televisions were still designed in the US, at least one manufacturer had a separate team of engineers review any new prototype, and start clipping things out. As long as it still worked, they'd leave it out, no accounting for stability or reliability.
 
Alex.....I'll take what is a dimmer resister for panel lights.....for $1,000
 
I trimmed the image down roughly, and I discovered later, imperfectly and google image search returns as the top hit:-

Aircraft Panel Lighting Dimmer - Lamar Model B-00396-2​


I'd say it is likely one of those, but perhaps not the exact same part.

1694958549506.png

1694959780701.png

Image I searched with:- (Google trimmed out the rubbish anyway.)
1694958615969.png
 
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It may be a Shunt. They are used to regulate voltage or amperage...
Ask your A/P. They should know...
 
Thanks, all. I've been away for a couple of weeks out of communication here. Thanks for all the input. Sure looks like the dimmer. Next time the glareshield is off I'll look at the back side for a label.
 
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