Has anyone used the motor driver with a 6v motor / PSU?


5 posts
by tobes » Thu Dec 27, 2012 8:09 pm
Hi,

I've been scratching my head over why my motor driver wasn't going, when I found a remark in this forum that the chip had a specified minimum supply of 12v, but seemed happy working with 9v.

I've only got a 6v battery / motor handy, and I was wondering if anyone else has successfully used a voltage as low as this, or whether to accept that I've got to buy a new motor / power source before going further.

Thanks for any help

--Tobes.
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by domesday » Fri Dec 28, 2012 12:41 am
The L6203 H-Bridge driver used on the Gertboard kit is a heavy duty DMOS motor driver that has a minimum input voltage rating of 12V it works at 9V for many people but due to manufacturing tolerances may not work for all. You will need a more powerful motor or an external motor controller board that works at lower voltages. Gert has said that he has changed the design on the assembled board to use a lower powered controller that will work with smaller motors, not that it helps you much I'm afraid.
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by bgreat » Fri Dec 28, 2012 1:13 am
You could try a 9v supply with your 6v motor. There is generally some leeway in the motor ratings. Just do not drive the motor to 100%. Limiting the motor drive to 65-75% should work without any damage to the motor.
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by tobes » Fri Dec 28, 2012 12:03 pm
Thanks, I was hoping I would see something at full power so at least I knew the chip was alive.

I shall see if I can find a handy 9v supply, otherwise I shall grab a replacement motor and battery.
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by domesday » Fri Dec 28, 2012 12:43 pm
You will get a voltage drop of about 1.5V across the controller anyway so you would be giving the motor about 7.5V at full power so you could probably get away with it if you are not running it for long periods.
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