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Hi. I'm back using my Arduino and for some reason, when I have a vex robotics motor hooked to it, it works better when connected to the computer rather than my 9v battery(really only like 8.82v, but USB is 5v usually.
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The Arduino shouldn't really be powering those large servers by itself, consider a secondary power source besides the one on the Arduino.
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Yes, even one servo requires too much current to work reliably for either USB or external power. And your use of a small 9volt battery is even more current limited then the USB power. To use servos in an arduino project on needs to use external power source of between 4.5-6vdc for the servos. Plan on using one amp per servo, i.e. if you want to power 3 servos use a regulated +5vdc power supply rated at 3 amps or better. Sometimes you can get by with less amps but that really depends on the specific servos used and how much mechanical load there are working with.

Four good AA batteries in series also makes a useful power source for servos.

Lefty
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The servos I'm using are rated 5V @ 50mA. I don't know why they wont work when each pin should be 1 amp..
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The servos I'm using are rated 5V @ 50mA. I don't know why they wont work when each pin should be 1 amp..

Could you show us a link where that servo's 50ma spec is given, that seems awful low for something that has a motor in it?

 And what do you mean about "each pin should be 1 amp. If you mean Arduino output pins they have a absolute max rating of 50ma each. And the Arduino +5vdc pin is limited by the total USB current limit of 500ma.

Lefty

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I thought I read that the Arduino pins were 1 amp. Huh. Ok well here's the link: http://www.vexrobotics.com/products/accessories/motion/276-2163.html It should be on there. I found it once, and I can't find it now. I did have it working before on a 9V. That was a while ago though.
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I thought I read that the Arduino pins were 1 amp. Huh. Ok well here's the link: http://www.vexrobotics.com/products/accessories/motion/276-2163.html It should be on there. I found it once, and I can't find it now. I did have it working before on a 9V. That was a while ago though.

Well the motor spec link inside your link says:

Motor Specs:
Free Speed 100 RPM @ 7.5 Volts
Stall Torque 6.5 in*lbs (approximately)
Stall Current 1.6 A (approximately)
Free Current 140 mA (approximately)

Lefty
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The servos I'm using are rated 5V @ 50mA. I don't know why they wont work when each pin should be 1 amp..

Actually I too own vex hardware and the current draw on the servos reaches up to 1.5A.
Its still too much to pull through the Arduino, you really need a secondary power source.
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I just looked at that. I must be thinking of the servos they have. I don't know but one of them is 50 mA. Is it possible I can get my motors working?
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