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I am currently in the process of building a quadruped robot that uses 12 SG90 servos, controlled by a PCA9685, for motion. I've found many examples of quadrupeds, but barely any mention of their power sources

I have tried many power sources, but have had no luck in getting the 5 volts the servos need at a high enough current.

Each servo can supposedly use up to 700ma when stalled, so around 10 amperes should be enough to power the whole robot, including electronics, at maximum strain, with current to spare.

The trouble is, I haven't been able to find any 5V regulators beyond 3 amperes that aren't overpriced or comically large.

What would be the best setup going forward? Should I chain several 18650 batteries (3.7V) in parallel and use multiple small boost converters? Should I design a PCB that includes many 5V regulator ICs? Is there a preexisting solution that can power multiple servos that isn't ridiculously heavy or expensive?

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    \$\begingroup\$ I havent been able to find any 5v regulators beyond 3a that arent overpriced or comically large - this is quite vague and subjective statement. The size and price are somewhat proportional to the functionality. If you have high demands - you get higher cost. \$\endgroup\$
    – Eugene Sh.
    Apr 11, 2022 at 20:02
  • \$\begingroup\$ And if you want lower price for a given power output, the size goes up. If you live somewhere that has surplus electronics suppliers look for someone selling Vicor or similar modules. You may luck out and get something cheap -- or not, that's the whole thing about surplus. \$\endgroup\$
    – TimWescott
    Apr 11, 2022 at 20:09
  • \$\begingroup\$ sorry for the vague language with pricing, i live in europe, and dont have access to fancy hobbyist stores like the ones in america.⠀ ⠀ i am able to get 2-3a 5v regulators and could in theory buy 3-4 and connect them, if thats practical/ a good idea. Ordering parts to make a custom regulator is another option, and shouldnt be too expensive either.⠀ ⠀ as for how cheap is cheap; i was targetting around 20 euro for the power supply, if that is even possible. \$\endgroup\$
    – helo
    Apr 11, 2022 at 20:13
  • \$\begingroup\$ get an adjustable high-efficiency SMPS module and dial it to 5v. Ones built around an LTC3780 or XL4016 chipsets would be able to handle 10A. \$\endgroup\$
    – dandavis
    Apr 12, 2022 at 6:34
  • \$\begingroup\$ LTC3780 and XL4016 boards look promising, thanks! \$\endgroup\$
    – helo
    Apr 12, 2022 at 15:47

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As far as commercial options, I did some quick searching and I found an 8-channel, 20A power distribution board by a company called Gobilda. I haven't heard of them before, but their products seem to cater to robotics and EM controls. The channels are controlled by DIP switches, but it looks like they can be easily desoldered and replaced with electronic switches.

This other website has some cheaper RC power supplies that should work well for an application like this.

Another option is to work at a lower current and use a gear reduction to reduce load on the servo, but there may not be commercially available solution as small or slim as you need. You'll have to research that based on what you know about your project.

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