Very simple servo control: what sort of power supply do I need?

Community General Discussions
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I’m looking to have a play with server control, without getting into the underlying electronics any more than I have to (I’m a programmer Jim, not an electrical engineer!) and without soldering and such.

I think I’ve picked a controller that will work for my first experiments: this one as it is inexpensive, can control enough devices (I only need one or two initially, but will no doubt expand later) and the manufacturer’s documentation suggests control will be possible using my own code running on Linux which will be a requirement at some point. My current understanding suggests any standard servo with 3-ping control (+, -, control) like this one should be happy to be controlled by it.

But I’m not sure what I need to look for to provide power to the servos. The controller itself will be able to draw from the USB link, but I’ll need something to provide an amp or two via the server power pins. Would a good PP3 battery be sufficient for initial experimentation? Is there available an adaptor that would allow a spare molex or floppy power connector from a PC PSU to be connected to it to provide servo power?

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Thanks, that is helpful. I got the impression from the documentation on Pololu’s website that the power drawn from the USB line was only sufficient to run the controller (most servos wanting to draw more then the 500mA a standard USB2 port will usually provide?) so I’ll grab one of the jack adaptors too to be on the safe side (I’ve got a collection of wall warts hanging about - I’m sure one of them will have outputs in the right range).

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Hi dspillett,

Welcome to the RobotShop Forum. If you are only using standard sized servos like the Hitec HS-322 and HS-422 and not subjecting them to much load, the USB port alone should not be enough to power them. You will need a separate 4.8V to 6V power supplyconnected to the Vin and GND pins, especially if you plan to use three or subject them to a load. You might use the Barrel Jack to 2-pin JST connector for ease of use. However, when powering motors from your computer’s USB port, you need to know that your computer’s USB hubs can only handle so much current (~500mA) and there is no protection in case something happens, which is why any manufacturer of a servo controller should tell you NOT to power the servo and controller directly via USB.

Hope this helps,