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Topic: 12VDC to motor shield too much? (Read 235 times) previous topic - next topic


Apr 01, 2020, 08:38 pm Last Edit: Apr 01, 2020, 09:21 pm by Bobsbees
When I run the s/w on my Arduino and motor shield it works OK without external power. As soon as I connect 12VDC to the shield the two output connectors (A and B) of the shield freeze and no longer work. When I disconnect the 12VDC, after a few minutes the shield works again if I do not connect external power. It appears to me that the shield is shutting down because 12VDC is too high, which it should be able to accept. When I connect a 9V battery to external power the shield keeps working, but a 9V battery is not enough to power the motors. Can anyone confirm if this is the case?

I have not cut the external power on the underside of the shield because it is my last shield and when I cut my other shield I believe I pressed too hard and cut whatever was under there as well. This is my last shield until the shops open and I do not want to break it. Can I put a resistor in series with the external power supply to lower the voltage to, say, 9VDC? The current shield is a no-name from China, the shield I broke was a genuine Arduino (tears).


There are dozens of different motor shields. Most will easily take 12V if connected correctly but I don't know about yours because you haven't given any information about it except "no-name from China".



I am aware it is a vague question as there is no manufacturer printed on the shield. If too high an external voltage is applied to a motor shield do they just cut out temporarily until the external power is removed?

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