25D mm Gearmotors + VNH5019

I connected TWO 25D gearmotors to the VHN5019 shield on the Arduino Mega2560.

When I tried to run the demo program of Dual VNH5019 Motor Driver Shield, the motors doesn’t turn, only has kind of vibrating noises between two motors which seems as they trying to run.

The motor’s power source is the 6V 500mA, AC-DC adapter.

Pls adv. Thanks


There are two types of 25D gearmotors, the low power gearmotors draw 2.2A at stall, the HP gearmotors can draw 6A at stall. A 500mA power supply is not an adequate power supply for a pair of either of those types of gearmotors. You should use a power supply that can source close to the combined stall currents (or more) of the 25D gearmotors you have. Can you try a more appropriate power supply and see if the motors run?


Thank you for your reply.

I’m using HP Gearmotor, but under no load on the motor (free run).
And, when I measure the 500mA power adapter, it’s about 2A.

So, is it still too low for the motor to run?

What is the min. current for such HP motor to run without load?

Pls adv.

Brushed DC motors briefly draw the stall current every time they start, so your power supply must be capable of at least that, without a substantial voltage drop.