L298N Motor shield and 2.8A DC motor - would it fry the shield ?

Hi

I have a brushed DC motor measures at 2.8A when it first starts for a few seconds then drop to 1.7A at normal speed. I wonder if I connect it with the L298N motor shield, would it burn the shield ? I understand the motor shield can handle a maximum of 2A.

Thanks for your advise.

Tony

Hi,

if the shield has a large heat sink it should be no problem as the L298 has 2 outputs that can be used together to get 4A. If there is only a small or no heat sink at all there is still the L298s internal overheat protection which will prevent if from failing immediately - however you won't be able to get full power and the chip may be killed after some time. (I found the L298 to be quite sensitive to constant overtemperature - despite its protection circuit)

Christian

Hi Christian

The shield has a large heat sink so I think it may be ok. There are 2 outputs on the board. I plan to use the motor for low speed so I think it may be ok. I concern only when the motor first starts, it draws higher ampere than the board specified but last only a few seconds. I will give it a go. Thanks for your help.

Tony

Using both channels in parallel should be OK. However, you'd be better off using a mosfet h-bridge chip such as http://www.pololu.com/catalog/product/1212. It has a much lower voltage drop than the L298N, so it runs much cooler and needs little if any heatsinking.

If you do use the L298N, then you need to provide a supply voltage around 3V to 4V higher than the motor voltage, to allow for the voltage drop in the device.