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pwm arduino Answered

I have a couple questions about driving motors from the arduino (I have a boarduino) - First off, these motors are from various walkmans and I think each one is rated for 1.7 volts. - If I need a transistor, can i use a 2n3904 (since these arn't giant motors) - How do I protect against the emf? The motors need to work going either way (clockwise or counter clockwise) - How would you program it so that the motor can go either forward or backwards?

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guyfrom7up (author)2008-03-30

oh, and does anybody have an idea how to operate the lever of a zif connector using a cheap motor?

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westfw (author)guyfrom7up2008-03-30

A servo-motor should do it pretty easily. Not cheap, though...

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guyfrom7up (author)westfw2008-03-31

is there any devices thay would ustilize a servo that I could take apart? The only thing I can think of is some rc cars, and I can't find any.

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westfw (author)guyfrom7up2008-03-31

not that I know of. Most cheap RC cars use some sort of cheap replacement where a more expensive device would use a servo. You might be able to get a stepper motor, perhaps with some gearing. (Mechanics always annoys me...)

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guyfrom7up (author)westfw2008-03-31

me too, I have the motors, I just don't want to make the gearbox, i mean one gear box takes hours and hours.

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westfw (author)2008-03-29

Do you have size restrictions? To do both directions, you typically need an H-bridge, which means 4 transistors, 2 each PNP and NPN. Or you could probably get away with a DPDT relay for direction (driven by transistor) and one additional transistor for on/off/pwm. Walkman motors are so efficient you might get away with driving them with logic chips, but I wouldn't recommend driving them from the AVR directly. Check the existing instructables on H-bridges, and/or the BEAM robotics motor driver archive

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guyfrom7up (author)westfw2008-03-30

Thanks, checking it out. There arn't really and size restrictions, I'm building an automatic avr programmer, and it'll kinda resembles are really cheap cnc machine (like 10 dollars total.

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