1. Home
  2. Electronics Design
  3. heat-shrink and component cooling

heat-shrink and component cooling

In the rc world brushless motor speed controllers are almost always a small board covered in heatshrink.

How much does the heatshrink affect cooling of the power chips? These things are often in the air-blast from a propellor. If they overheat they either shut down or burn, likely crash eitherway. The heatshrink is mostly to protect physically from bumps and knocks, I'm thinking remove the square over the chips and stick a small heatsink on, but if won't make much difference the weight saved without it might be better. Total aircraft weight is under 100g.

Reply to
oak
Loading thread data ...

On Sun, 20 Mar 2016 12:02:35 +0000 (UTC), oak Gave us:

You can buy small Al "trees" type heat sinks the same size as a chip you want to cool off or radiate from. Some of the reason is to keep it from direct moisture incursion. So once you find the item you want to dissipate from, you sink that item, then use a small amount of mil grade RTV/Adhesive to seal it back up all around. Or you could spray it with a conformal coating. Many are UV exhibitors which show up under UV source to show any places missed.

So, a couple grams for the sink and a gram or so more for the sealant.

That isn't so much.. Weigh it first as is. Then weigh it again after the shrink is removed, then weigh the sink and a dab of the sealant to know the differences you are going to be incorporating.

Reply to
DecadentLinuxUserNumeroUno

Measure temperatures on the ground, with aircraft held in a jig.

If there is a real problem, then deal with it.

RL

Reply to
legg

Does the original shrink tubing create a ?tunnel? around the PCB such that the air flows though the tube and across the ICs? Likewise you could add small finned heat sinks to the ICs and orient them such that the fins are in-line with the airflow. Heat shrink the whole thing, making sure that the ends are open to airflow (and placed in the prop?s airfstream).

Reply to
DaveC

** Ones like this?

formatting link

Pretty much impossible to add a heatsink to the mosfets - the PCB is acting as one, long as air can flow over it.

The square chip with all the legs is a uP and does not get hot.

FYI:

The heatshrink is there to stop accidental shorts to objects like the motor or battery packs.

.... Phil

Reply to
Phil Allison

I thought the prop wash from model airplanes was very dirty and would get oil/fuel on the electronics. That might be very bad for the longevity of the circuits. If nothing else, it would cover them with grease that would hold dirt and create a huge thermal barrier.

--

Rick
Reply to
rickman

electric model airplane.

--
  \_(?)_
Reply to
Jasen Betts

On Sun, 20 Mar 2016 21:55:21 -0700 (PDT), Phil Allison Gave us:

Not really. Solder them onto copper strips (heavy gauge) by means of lifting that part from the big pad it is on and adding the strip between, leaving the legs connected. Add a air blown sink to the strip extension

Not much. Mostly by conduction only.

Generally not.

That is why I suggested the mil RTV.. It is removable for servicing too.

Reply to
DecadentLinuxUserNumeroUno

On Mon, 21 Mar 2016 01:02:01 -0400, rickman Gave us:

What part of "motor controller did you miss? I am pretty sure he is talking about electric motor driven props.

Reply to
DecadentLinuxUserNumeroUno

** ROTFLMAO !!

The OP is asking about an **electric model aeroplane**.

** Too damn funny for words.

The Prickman has excelled himself.

.... Phil

Reply to
Phil Allison

Fuel? Electrons, you mean? Like in "sparks"?

Reply to
Rob

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.