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Is there diode inside the 131:1 Metal Gearmotor 37Dx57L mm with 64 CPR Encoder (No End Cap)?


Dear All,

I have this motors and would like to do some interesting work with it.

The motor of interest is https://www.pololu.com/product/1447.

I would like to ask if anyone know, if this motor inside include a flyback diode for protection. I am not really confident to dismantle it to check. I am asking as I would like to know if there is a need to include diode in my project design if the motor do not include diode inside it.

Thank You!


It would not make sense to have a diode built in, except for certain special purposes.

You can use a flyback diode across the motor terminals only in the case that the motor will rotate in just one direction.

Bidirectional motor drivers/controllers have built in flyback diodes. How are you planning to control the motor?


Dear Jim,

I l298

I planned to use the motor similarly to the circuit. Is the placing of the diode good for bi-directional? I plan to control it by connecting to a motor driver and then to a microcontroller.

Thank You!


The L298 driver is an extremely poor choice for that motor. It can’t handle the stall current, and will simply overheat. The lowest cost Pololu option that would work with that motor (with light loads) is https://www.pololu.com/product/2960 . For heavier loads, you might need https://www.pololu.com/product/1212

Both are bidirectional, with built in flyback diodes.