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I'm working on a robotics project right now and my limited DIYer knowledge of electrical circuits is failing me. I need to power 7 Rage Standard Metal Gear Servos (RGRS104-16-6vm) and 4 RadioShack Micro Servos using a Tenergy 6V 3300mAh NiMH Battery Pack. I've made a diagram of the circuit I'd like to make, but I feel like there's more to this type of circuit than I've planned for. There are only 9 servo connections because two pairs of Rage Servos will be wired together to share the same battery and signal connection. I'm also open to using a different battery if that's what it takes to make the robot run smoothly (It has to use a rechargeable battery though; It's meant to be portable.) Also, the Arduino has it's own battery, so no worries there.

Would you please point out what I need to add to my circuit to make sure it works properly?

Thanks in advance!

Servo Power Board Diagram

More Info:

Rage Standard Metal Gear Servo RGRS104-16-6vm Dimensions: 40.8 × 20.1 × 38 mm Weight: 56 g Operating Speed: 0.18sec/60degree (4.8V), 0.16sec/60degree (6V) Stall Torque: 9kg.cm/125.2oz.in(4.8V), 10.2kg.cm/141.9oz.in(6V) Operating Voltage: 4.8V~6V Control System: Analog Direction: CCW Operating Angle: 180degree Required Pulse: 500us-2500us Bearing Type: 2BB Gear Type: Metal Motor Type: Carbon Connector Wire Length: 30 cm.

RadioShack Micro Servo Voltage: 4.8~6.0V Torque: 1.5kg/cm at 4.8V; 1.8kg/cm at 6.0V Speed: 0.12/60ТА at 4.8V; 0.10/60ТА at 6.0V Size: 23x11.5x24mm Weight: 8.6 g Use Angle: <=160ТА

Tenergy 6V 3300mAh NiMH Battery Pack Chemistry: Ni-MH Cell Size: Sub-C Nominal Voltage (V): 6 Capacity (mAh): 3300 Max Continuous Discharge Current: 6A Battery Charging Current: Standard: 1A Weight: 10oz. Dimensions: 112 x 46 x 23mm (LxWxT) Connector: Hitech

Link to Diagram: https://i.sstatic.net/L4GtP.jpg

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  • Servo's can draw spike currents, so you theoretically need a big capacitor to be able to supply such power needs. It may also help to use a battery type that has a higher maximal discharge current (but I believe internal resistance of a battery may rise over time).
    – aaa
    Commented Jan 5, 2018 at 18:54
  • Also, paint is a nice program to draw, but for drawing circuit boards you should try Fritzing, cadsoft eagle or something like easyeda. Fritzing has a board view that resembles your drawing, but with pre-made components.
    – aaa
    Commented Jan 5, 2018 at 18:57
  • 3
    I'm voting to close this question as off-topic because it is entirely about RC servos and not at all in any way about Arduino. Try an RC hobby site for the best advice, in particular, in figuring out if your pack is four or five cell, and in the case of the latter if it is or is not appropriate to use directly.
    – Chris Stratton
    Commented Mar 6, 2018 at 16:44

1 Answer 1

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One thing to ask, it is not clear if you are going to run the Arduino Uno off the same battery, or off a different battery?

If the same battery, then you are likely going to need to create an V+ output for the Uno, but will need to ensure that any drain from multiple servo's running are not going to impact on the voltage supplied to the arduino, and also that the voltage supplied is compatiable with the Uno (e.g. don't run 6V+ into the 3V outlet)

Just to note as well, the Arduino Uno has (to my knowledge) only has about 6 PWM pins which is what you will need to drive the servo's through the signal pin. You can add I2C PWM expanders which give you more pins (e.g. https://www.adafruit.com/product/815) but YMMV

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  • 3
    the Arduino Uno has (to my knowledge) only has about 6 PWM pins which is what you will need to drive the servo's through the signal pin. - Actually that's not true (and it took me by surprise too when I found out): The Arduino uses timer interrupts not PWM in the servo library. It's set to drive 12 servos per timer, and the '328P has 1 timer allocated to it, so can directly drive 12 servos on any pins of your choice no problem.
    – Majenko
    Commented Aug 7, 2017 at 9:53
  • No, the Arduino is powered by a separate battery.
    – Luke A.
    Commented Aug 7, 2017 at 15:04

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