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Author Topic: Current Supply for Simple Servo Set Up: 5V 10A supply for Hitec HS-805MG?  (Read 139 times)
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Hello!
I am currently in the process of designing a kinetic sculpture, but would like to run my reasoning  by the community to check it's sound before I make any expensive mistakes!

Using the setup detailed in the below schematic, I am hoping to run one or two servos through a simple sweep motion, from a 0 to a 45 degree angle. This would be running on an Arduino Uno connected to a generic mini breadbord.


These servos will probably be under a lot of strain, as I will use them to lift a series of heavy wooden panels. I was planning on using heavy duty Hitec HS-805MG analogue servos, as they have high torque capabilities (http://www.servocity.com/html/hs-805mg_servo.html#.U6Li9O0WE9V). Unfortunately, I can't find the Stall Current Draw for these servos, but I suspect that they could drain as much as 4A when operating at maximum load capacity.

I was hoping to power these directly using a 5V 10A switching power supply (http://www.adafruit.com/products/658), which I would connect directly to the breadbord as detailed in the schematic (common ground with Arduino etc.).  My question is, as the power supply operates at such a high amperage, is there the possibility that it could fry the servos if they are not drawing high amounts of current?

If they were to be more efficient than I suspected, and only draw 3A maximum - would the power supply only deliver the current necessary or would it oversupply the circuit and potentially fry the equipment?

My understanding is that it will only deliver the current that the circuit draws - so 10A is only a limit to how much it could supply. I am correct in thinking this way?

Thank you in advance for the support, I am new to these things and every little bit helps!  smiley
Michael

 
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servos are safe unless you give them harder work than they are ment to handle.
Power supply can be a plant capable of megaamps. Dosnt matter as long as voltage is corrent.
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Dosnt matter as long as voltage is corrent 

Do mean "Doesn't matter as long as voltage is constant ?"
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Dosnt matter as long as voltage is corrent  

Do mean "Doesn't matter as long as voltage is constant ?"

More likely 'voltage is correct'

'
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Yeah, I see. That makes sense. Thanks.
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My question is, as the power supply operates at such a high amperage, is there the possibility that it could fry the servos if they are not drawing high amounts of current?

If they were to be more efficient than I suspected, and only draw 3A maximum - would the power supply only deliver the current necessary or would it oversupply the circuit and potentially fry the equipment?

Common misconception.

A _regulated_ power supply outputs a constant voltage until it is overloaded, then the
voltage will droop (or the supply cut out automatically).  There's no way it can push
more current into a load than the load takes at that voltage - the voltage is what sets
the current in the load, in a way that's a property of the load.
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