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Basic ESC to a heat sink

We are planning to use the “Basic ESC” in our canister design. We need some inputs on how to mount the ESC to a suitable heatsink; as suggested in the “Installation and Thermal Consideration”.

The ESC doesn’t have a mounting slot or screw mount to add the heat sink too.

Also is there a way to mount these on a PCB? We might be using ~8 of these in our system.

Hi @nras,

Note that the suggestion to mount the ESC to a larger heat sink is not a requirement, but an option in the case that they are overheating in the exceptional circumstance that they are being used at an especially high duty cycle/current, or in an enclosure that is already hot or otherwise constrained. In the vast majority of circumstances, the ESCs will do just fine by themselves without additional cooling.

For example, in the BlueROV2, the ESCs do not overheat and are simply left unobstructed inside the watertight enclosure.

If a heat sink is necessary, the common method is to stick the ESC MOSFETS directly to a heat sink with thermally conductive double sided tape or epoxy.

-Adam

Hi Adam,
Thanks for the prompt response!

A couple of follow up questions:

1: Is there a maximum power rating (tested) at which the ESC needs to have an additional heatsink? E.g if we are drawing 200W through the ESC; does it need to have the external heatsink?

2: Also is there any recommendation for adding the ESCs on a PCB; to consolidate the design. As I mentioned before, we might need to use 8 of them in the system.

Appreciate your quick response!

Naman

  1. Not sure if there’s a tested value where a heat sink becomes necessary, but note that heat increases more with current than voltage, so 200W at 20V would run cooler than 200W at 7V.

  2. They’re not really designed to be mounted on anything other than being strapped to a flat surface. In saying that, you could presumably desolder the input power and signal wires, and use some bulky right angle connectors (careful with the power rating) to run the power connections to a power and ground plane of a 2 layer board, and you could use some smaller header pins soldered to the signal positions and routed to something like a ribbon connector slot for your 9 signal wires (1 for connecting pixhawk ground to your ground plane). Depending on how you want them connected, they could either be fully supported on soldered header pins, or you could use some heat-resistant 3D printed slots to keep sit them in (basically just not PLA).

That’s how I did it. All 8 esc are mounted on the aluminum bracket in the lid.

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That’s really nice!

Are you collecting putting multiple sets of thruster wires through each penetrator, or do you have another couple of penetrators in the middle of the hole for the tether and power connections?

there is one cable per truster, which is soldered directly to the ESC output.
the 3 penetrators in the middle are for power, vent plug and a spare.

the power sense module is located in the middle.
There is only a signal plug with 9 conductors + a power plug with 2 conductors that must be disconnected to remove the lid.

signal cables, depth sensor, temp sensor, tilt, camera light, etc. have penetrators in the lid on the other side of the enclosure. (I do not have a dome, but a separate camera)

1 Like

Cool, thanks for the info :slight_smile:

Having no dome definitely sounds helpful in this case, for the extra penetrator space :+1: