Voltage regulator and servo current

Robotics and electronics discussion Electronics
1

My setup:

  • Maestro 12 channel servo controller
  • Running nine 6v servos
  • Servo spec: Stall Torque (6V): 25.3 kg.cm
  • Power supply: Mean Well 24 volt 14 amps
  • Pololu 6V Step-Up/Step-Down Voltage Regulator S18V20F6

If I step down the power supply to 6 volts,

  • is amperage reduced?
  • what is the total amps I need for all nine servos?

Thanks

2

Hello,

Our S18V20F6 regulator is capable of producing up to 2A, so it is probably not practical for nine servos. What are your servos, and what is the input voltage to your regulator?

-Dan

3

Dan,

Sorry, I meant to say I don’t have a regulator. Looking for one that will give me 6 volts to
use with my power supply: Mean Well 24 volt 14 amps. Servo spec: Stall Torque (6V): 25.3 kg.cm.
Any recommendations?

Thanks.

4

Hello,

Thank you for the clarification, but I still need to know the stall current of your nine servos before I can make a recommendation.

-Dan

5

Dan,

Can’t find Stall Current on the data sheet.

Motor is Servo Motor: PDI-6225MG-300 (JX 300).

How will knowing the Stall Currenthelp?

Going to try this instead of a step down voltage regulator:

Mean Well power supply with 5 volts @ 10 amps.

Is one amp per servo going to work?

Chuck Krause

6

Hi, Chuck.

The stall current gives a guideline for the maximum current draw you can expect from each servo so you can budget how much current you need to be able to source from the regulator and power supply. I cannot say if 1A per servo is sufficient for your servos; some servos can draw many times that, but from the torque specifications of those servos, I suspect they draw more than a standard servo (which we normally suggest budgeting an amp each for).

If you have a bench-top power supply, you might try connecting a few servos and moving them around and see if you get a voltage drop from the load of the servos(a sign that they are drawing more than the power supply can handle). If that seems okay, you could add additional servos one at a time again moving them and seeing if you get a voltage drop. If you do not get a voltage drop, the maximum current for your bench-top supply will give you some idea what current you need. You can also try adjusting the maximum current on your supply down until you get a voltage drop to further narrow that range.

-Derrill

7

Derrill,

Great info. Thanks.

Don’t have a bench top power supply yet.

Think I’ll try a power supply of 5v @ 18 amps.

Too many amps over won’t hurt will it?

Chuck Krause

8

No, having a supply capable of handling more current will not hurt anything; the servos will draw what they need from the supply.

-Derrill

9

Thanks. Happy Thanksgiving.

Chuck Krause

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