Servo not working properly

Hi i'm doing a small circuit that should power 3 servos.

The circuit is the following

The servo giving issues is the bigger one. The AR-3606HB. it just goes wild and crazy.
The other servos works just fine. i Think it has something to do with the power... but even adding the mosfet it still doesn't work.

The power is given by 4 AA batteries.

what can be wrong?

What on earth is the MOSFET supposed to be doing across the servo leads? You've
shorted out all the MOSFET leads too by the look of it with those short blue wires.

If your batteries don't have enough grunt for the servo, you need batteries that
can deliver more current.

plz i'm noob with electronic, can you explain me better what you mean about both things?

how am i supposed to know which batteries to use? i tried a 9v but i had same errors

any help?


You need to look at the spec for your servos for a start, then set your arduino up so that the servos have their own power supply, the 5V from the arduino cannot supply the current needed.

Can you please post a copy of your sketch, using code tags?
Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png or pdf?

9V transistor batteries, the type used in smoke detectors will not be able to supply you with the current needed.

Tom..... :slight_smile:

Have you tried fully charged AA NiMh rechargeable batteries in your battery holder? They can provide high currents and should be sufficient to allow you to test your application.

However 4 NiMh cells only provides 4.8v which may be on the low side for your servos. Maybe you would need 5 cells (for 6volts).

You have not answered @MarkT's question about the "black thing" at the bottom right of your breadboard. What is it, and why?


Assume several amps are needed, servos use a lot of peak current.

Get rid of that MOSFET and those short blue wires, they appear to short everything
out (perhaps that's only in the fitzing diagram).