ev3 large motors: do they have a built-in fuse?

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HaWe
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Joined: 04 Nov 2014, 19:00

ev3 large motors: do they have a built-in fuse?

Post by HaWe »

About ev3 large motors: do they have a built-in fuse?

I obeserved the following issue (reproducable):

A metal tank tread chassis was driven by 4 large ev3 motors on the lawn.
For experimental reasons they all have been connected directly to a 12V battery (4500mAh).

Now under very heavy load weight the motors have been braked until standstill, but after removing the load completely they did not immediately restart rotating but not until about a minute later, after then everything worked fine until the next braking. Voltage was > 11-12V at any time.

This made me think of maybe kind of bimetal fuse inside the motors.
mightor
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Re: ev3 large motors: do they have a built-in fuse?

Post by mightor »

I just ripped a motor apart and see something that looks a lot like a thermal fuse.

Image

Note that is not the final production hardware, so the final hardware may look slightly different.

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HaWe
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Re: ev3 large motors: do they have a built-in fuse?

Post by HaWe »

ahaa... thx!
8-)
philoo
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Re: ev3 large motors: do they have a built-in fuse?

Post by philoo »

Looks a lot like a 0.75A rated Bourns MF-MSMF075 resettable fuse... (the same used in all PF battery packs)
Philo
HaWe
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Re: ev3 large motors: do they have a built-in fuse?

Post by HaWe »

thanks for confirming my suspicion !
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