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Topic: Current limiting circuitry for servos (Read 982 times) previous topic - next topic


Hi guys,
Apologies if this is a dumb question - I've searched the forum for answers, but none seem to quite give me an affirmative yes or no.

I'm going to be driving 6 servos - (Hitec HS 645mg High Torque servos to be exact)
Half the time only 2 servos will be active, but at other times 4 or even occasionally all 6 will be running for a short period)

I'm powering the system from a regulated power supply, set to 6V, with maximum 2.5A output.

I'm a little confused by weather I need a Motor Shield or not. Can I string all the servos off the same power supply, without a current limiter protecting each servo? - Just set the PWM line when I want the servo to actuate?
Presumably the supply will give whatever current is drawn, and no more, so when only 2 servos are running, I don't risk burning them out?
....or do I have my head in coo-coo land?!



The PSU will supply exactly what's needed and no more, so you should be right to just connect them all as long a 6 don't draw more current than the PSU can supply.

Rob Gray aka the GRAYnomad www.robgray.com


fabulous - Thanks Rob - that's exactly what I wanted to hear!
I'll probably need to supply them with dual sides of the power supply to feed enough current to the little blighters when they're under load...but if that's all I must do its not so bad...!

Thanks again


Your power supply should have a + voltage and a Common or ground. Ground from your servo power supply should be connected to Arduino Ground. Servos don't need current limiting resitors.

If you don't supply the servos from both sides of the supply they won't work...


Yep! common ground - check! I've been frustrated  by that one in the past!
Thanks again!

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