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Topic: Arduino VIN pin question. (Read 8152 times) previous topic - next topic

TechnoGuy

I am going to power my Arduino board with  with a 12v power supply.
My question is will I have 12v available at the VIN pin to power a 12v motor?

retrolefty

Quote
My question is will I have 12v available at the VIN pin to power a 12v motor?


Yes, the 12 volts will be avaible at the Vin pin. However the maximum current draw from this pin is limited by the series polarity protection diode on the board, which is generally a one amp diode. If you require more then that you had better connect the motor load directly to the 12v power supply.

TechnoGuy

One motors current rating is 130mA (.13 Amps) at 1.56 Watts and  
the other  motors current rating is 290mA (.29 Amps)  at 3.48 Watts. I only plan to run one of them.  But I am not sure which one yet.

floresta

#3
Jun 30, 2010, 02:12 pm Last Edit: Jun 30, 2010, 02:12 pm by floresta Reason: 1
Quote
My question is will I have 12v available at the VIN pin to power a 12v motor?

No, there will be a voltage drop of approximately 0.5 - 0.7 across the series polarity protection diode.  Your 12 volt motor will still run, but to deliver the same power that it does at 12 v it will require more current than it would have used at 12v..

Don

TechnoGuy

@ floresta,

Sorry to be a pest but I am new to this and learning at a rapid pace each day.  Will adding a Transistor Amplification circuit with a N channel MOSFET  correct the issue that you stated above.

floresta

Why don't you go to some of the robotics sites and see what they suggest.  Don't worry about what microcontroller they use, the circuitry will be essentially the same.

Don

keeper63

Quote
One motors current rating is 130mA (.13 Amps) at 1.56 Watts and the other  motors current rating is 290mA (.29 Amps)  at 3.48 Watts. I only plan to run one of them.  But I am not sure which one yet.


BTW - are those values "running current" (no load) or "stall current" (loaded)? If they are for no load running, realize that the stall current (and consequently, dead startup current draw) can be much higher...
I will not respond to Arduino help PM's from random forum users; if you have such a question, start a new topic thread.

TechnoGuy

I will bring the power for the blower straight in off the off the power supply that should alleviate any problems.

Thanks Guys

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