Electronics > Electronics

current supply for servos

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dv.phaneeswar:
sir,
firstly i want to declare that i am very poor in electronics. k if i come to the point i am constructing a  hexapod robot which consists of 14 servos (Futaba S3003) controlled by axon. i am using 6v 2300 mah niMH bateries but they are getting exhausted with in 3-4 minutes so i have decided to buy an 6v adapter. so can any one help me about how many amperes adaptor is needed for my project.

there are 6v 350ma adapters and 5.2v 1000ma adapters available for me in the market so which one you would prefer for this project.

jkerns:
Based on your numbers (2300 amp-hour, 4 minutes) I would think you would need AT LEAST 4 amps (4000ma) from a power supply - but more likely about twice that.

OOPS - I slipped a decimal place somewhere - the numbers posted by jwatte are better.

jwatte:
2300 mAh, 4 minutes, means your project draws at least 30 amps, which is 30000 mA. The math is simple:
2300 mA * hour / 4 min * 60 min / hour = 34500 mA == 34.5 amps. The "4 minutes" time and the "2300 mAh" capacity is rather full of variation, though.
If you average 1A per servo, and have 14 servos, you need more than 14 amps in your power supply.

I suggest that you get a benchtop power supply with at least a 30A capacity. You'll find those things in industrial supply stores and the like.

dv.phaneeswar:

--- Quote from: jwatte on January 29, 2013, 01:02:46 PM ---
I suggest that you get a benchtop power supply with at least a 30A capacity.

--- End quote ---

i am having a doubt i dont know wheather it is correct or not but correct me if i am wrong.
when the servos are in ideal condition then all the 30 amps current will be send to microcontroller or when only one servo is working then all the 30 amps will be send to only one servo will damage the microcontroller or servo.
if i select a high current adapter will it damage the servos?

jkerns:
The actually current flow will depend on how many servos are drawing power. If we assume they draw about 2 amps each when moving, then if one servo is moving, the power supply will give you 2 amps. If 10 are moving they will draw 20 amps. etc.

The "30 amp supply" is capable of supplying up to 30 amps at some voltage. It won't make the circuit draw 30 amps.