ESC Sanity check

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voorsk
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Re: ESC Sanity check

Post by voorsk »

In case anyone's interested, there is also a 3-way version of the ESC: https://www.aliexpress.com/item/32946648379.html

Mine arrived yesterday, and I'm gonna try sticking it in my axebot to control drive and the axe, rather than the DasMikro and Vex29 that it currently has. Should save a bit of space and dodgy wiring! :)

Here's a couple of closeups of the board (not embedding photos, as it might be confusing): https://flic.kr/p/2h9YWYo & https://flic.kr/p/2ha1G5K (through-holes! yay!)
Team BLEEP Suspicious Houmous / Sprouting Potato / Fermented Melon / Black Carrot
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Ocracoke
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Re: ESC Sanity check

Post by Ocracoke »

I'll be interested to see this at BotFest, I am curious as to how robust it will be.
Team Kaizen

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MarkR
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Re: ESC Sanity check

Post by MarkR »

Not bad, I notice:

* Yay, through-hole pads for the motor wires :)
* Boo, surface pads for the battery connector (would be super-bad if it comes loose and shorts)
* They use my favourite chip, rz7899

Did it come with the big electrolytic cap or did you add it?
Robots: Betsie - RaspberryPi controlled flipper bot with gyro stablisation - too clever for her own good?
Stacie - tidy flipper; 4wd driven by hair bands
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voorsk
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Re: ESC Sanity check

Post by voorsk »

The big cap came attached. That's like a top-up tank for the battery, isn't it? Evens out voltage sags during sudden load, or something. I think I need space more than I need to worry about voltage sags, so I'm gonna lop it off. :)
Team BLEEP Suspicious Houmous / Sprouting Potato / Fermented Melon / Black Carrot
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MarkR
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Re: ESC Sanity check

Post by MarkR »

Yes, in general capacitors are usually there to even-out spikes in load caused by motors turning on and off. There may be some smaller caps on the PCB which will do well enough.

Usually there is a capacitor on the 5v regulator too, which is where you mostly need it, because it's vital that the electronics supply isn't interrupted. If the RX microcontroller reset itself due to a power brownout during battle, your robot would be a sitting duck for possibly a few seconds until the rx restarted and got a signal again.

EDIT: PS: Good luck with your axe-bot. We need more axe-bots. I love axe bots, especially if they are rediculously powerful and fast.
Robots: Betsie - RaspberryPi controlled flipper bot with gyro stablisation - too clever for her own good?
Stacie - tidy flipper; 4wd driven by hair bands
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MarkR
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Re: ESC Sanity check

Post by MarkR »

Ok, it is super difficult to get info about the MX2020b IC.

It is made by Chinese company sinotech, whose web site http://www.mixic.com.cn/ blocks access from outside China.

There is a 1688 (Chinese ebay thing) page which contains some info here:

https://detail.1688.com/offer/596031371053.html

LCSC (Chinese reseller) don't stock this part and don't have its data sheet, but they do have some other Mixic parts.

It looks like it's a dual motor driver chip in sop16 package. Maybe not really robust, because MichaelG92 had one fail in his picture.

I know some robot builders have used the MX chips before, they are *really* cheap, open any cheap toy and you probably find some, but they're possibly not nearly as robust as my favourite rz chinese chips.
Robots: Betsie - RaspberryPi controlled flipper bot with gyro stablisation - too clever for her own good?
Stacie - tidy flipper; 4wd driven by hair bands
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