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Author Topic: How many Amps?  (Read 965 times)
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Netherlands
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How many amps would I be able to draw from the 9V/Vin pin on the Arduino board?
I want to connect a DC motor which might draw up to 50 A...

Thanks, Mega
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I don't know what the current rating is, but I'd bet money it's a lot less than 50A.

Do it the other way around - power the arduino from the motor's source, instead of pulling motor power through the arduino.

-j

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Wow, 50A is gonna require a pretty serious power supply.  Can you give us more info about the motor and what it's doing?
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the Vin power is limited to 1A by the "reverse polarity protection diode" between it and the connector.  It's limited to not much more than that by the current capacity of the connectors (probably 2A max for the "Power" socket, and no more than 5A for the Vin coaxial connector.)  The PCB traces probably aren't good enough for 5A, either.
For 50A, you'll need a separate supply, with somewhat careful attention paid to connectors and such.  Take a look at what the remote control people do for their high-power electric motors...
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Your definitely going to need some isolation between the Arduino and your motor.
It cant handle anything like that directly.

Oh and if you ever accidentally short any of your 50A wires, make sure to capture it on video. ;D
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Quote
Wow, 50A is gonna require a pretty serious power supply.  Can you give us more info about the motor and what it's doing?
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For 50A, you'll need a separate supply, with somewhat careful attention paid to connectors and such.  Take a look at what the remote control people do for their high-power electric motors...

I'm actually using a remote control car as the base for my robot, see http://megabotblog.blogspot.com/.
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Netherlands
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This is the engine I would like to control with an Arduino:
http://www.modelsport.co.uk/?CallFunction=ShowSpecification&ItemID=18376

During normal usage it draws 7.9A, with high ballast is draws up to 50A...
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That is a brushed motor, right? Why not use an ESC (Electronic Speed Control). You can use PWM from Arduino to control the speed of the motor. With an ESC it is easy to separate the motor from Arduino.
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Yes, it is a brushed motor.
I try to use an ESC, but I haven't figured out how to control it with an Arduino.
See this thread: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1197812774

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