Power supply recommendation

[James H Phelan]

Team

Seeking recommendations for power supplies.

I've used a hacked brick power supply to run my Pi 5, accessories and even drive it around on a tether.

But it recently conked out on me.  

A different laptop power supply just isn't up to the job.  Nor is a scavenged tower PC supply.

I have a Midzoo 15A buck converter as the first stage in my Stingray robot and it can't handle that.

The PS shows 16V unconnected but drops to 6V across the buck converter input with nothing at the output.

Google AI overview tells me many PS's can't handle the initial amp surge.

This is confirmed as a LiPo battery powers the buck just fine.

What do y'all use for bench / tethered power for your modest size robots?

Right now I just have a 2x7A RoboClaw running 2 Pololu gearmotors and a powered USB hub feeding the RPi 5 w/ PCIe memory, YDLIDAR, OAK-D camera, and IMU.

Next step would be the Open Source Rover with 10 gearmotors (6 drive, 4 steering) via 5 x 2x7A RoboClaws, and the same accessories.

RoverDoc

-- 
James H Phelan
"Nihil est sine ratione cur potius sit quam non sit"
Leibniz

[Chris Albertson]

Why not use a battery?   I mean it is a robot with wheels, it needs to move.  Make the battery about 12 to 14 volts and it is easy to find a lithium battery that can supply 100+ amps.   The best robot batteries (best weight and size for the power) are the ones made for FPV drones.  But cheaper ones are made for electric fishing boat motors.     Decide on a connector style. XT90 is good.

Then buy a “Meanwell” 12 volt 50 amp power supply and attach the same XT90 connector.  Now you can swap the power supply for the 12 volt lithium battery.      You can also use some heavy #4 wire to make an XT90 to XT90 extension cord.

Be 100% sure to also place 90A inline fuses on the battery side and power supply side of the cables. 

Meanwell is the best brand of Chinese power supply.   Many others are copies.  They might be OK, or not.  Buy from a reliable source.  I linked to Amazon below but Digikey might be a more trusted source.   If you buy the Meanwell brand, not a clone or a counterfeit, it will be bomb proof.

Figure out the PEAK power needed and then buy a power supply that is at least 1.5 times bigger than the peak demand.

Then, on the robot, you use DC/DC converters to drop the 12 volts to whatever is needed.

For bigger robots, I would consider using a 24 volt system.  That means 24 volt motor, 24V battery, and 24V Meanwell power supply.  This way, the current is reduced by half, and you can use normal wires.  Go 36 volts on a even bigger bot.

Beware, the XT90 is rated at 90A, so the fuse cannot be larger than 90A, and you’d need at least #4 wire.