10A Buck Converter - RC Sevo's

[Docara]

Hi,

I'm just looking into the feasibility of driving  a couple of RC Servos from an automotive source and would like some advice.

First off the Servos will be either 7 or 8.4V and have a stall current in the range of 6-8A. And the Power cables would need to run approx. 2-3m.

Now I have only ever needed linear power supplies up to 2A so I've used our old friends the 78xx series. It is tempting to buy one of the multitude 10A+ Buck converters from our favourite auction site, but I don't know the implications are of using Buck converters with reference noise etc to surrounding equipment and to the electronics on-board the servos themselves - not to mention the long-term reliability

The alternative is to trawl through datasheets and use manufactureres application circuits to knock up a circuit without knowing good PCB layout practices or experience in this area.


Your thought would be most welcome
Thanks
Matt

[AustinR]

Reliability is component-specific, so I cannot comment on the longevity of using specific buck converters long-term.

However, I can comment a bit on controlling output ripple. Without knowing the specific application or requirements, I don't think you'd have to worry about servo issues too much, but using a capacitor on the output side of the buck converter should reduce how much ripple your servo is seeing.

I found a decent video on youtube covering this here: https://youtu.be/G-Llhy2ViUY

Hope it helps!