Asked — Edited
Resolved Resolved by Steve G!

Two Wire Servo

Evening All

Electronics novice here :-)

I'm attempting to connect a two wire servo (need more torque) to EZ. Is this possible?




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It sounds like what you have is a DC motor, not a servo. A servo needs three wires, ground and positive to supply power, and a signal wire to get the information it needs to turn in which direction, and how far.

With a DC motor (which I suspect you have), you will need a motor controller or H-Bridge. This allows the motor to go in either forwards or reverse directions, and controls the speed (if the motor controller or H-Bridge has a speed control option). This connects to the EZ-B digital pins and the two motor wires connects to the two motor output on the motor controller. Below is a very good tutorial a member wrote which explaines what a H-Bridge does and how to connect it. :)

H-Bridge tutorial.


@Steve's right, It's a DC motor.... Is this a Vex product? You will need a H-bridge, sabertooth or another type of motor controller to use it....


I thought it was odd with only two wires but since it was listed as the GWS Heavy Duty S777 6BB servo Motor I though perhaps it was something special. Link is below:

I've worked with H-Bridges so that's not a problem.


Daniel :D


@Mulberry The above link you provided ( GWS servo) indicates it is indeed a normal 3 wire servo...


The GWS Heavy Duty S777 6BB servo Motor is compatible with RC systems manufactured by Futaba, JR, Hitec, Airtronics (Sanwa), Multiplex and any systems using 1,5 ms neutral. It comes with Futaba connector (for special orders: Contact Us to request a specific connector).


Do you actually have the device in hand? The photograph shows 3 wires, and the description is that of a regular servo.



Good idea Alan... @Mulberry do you have a pic or link to exactly what 2 wire motor you are referring to?

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I agree. The one in the photo does look like it has white signal, red Vcc and black ground wires.

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Like the others asked, post a pic if you can, and let's see what you've got.


Big whoops :D

There are 3 wires. Last year I had separated them, installed the servo in it's bracket, and the third wire got tucked out of sight. Lesson learned. Start a step, finish a step.

Thanks everyone,


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Right, it's all making sense now. I thought you were supplied a dodgy servo for a minute. Thanks for letting us know. ;)