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Motor mount kit voltage question — Parallax Forums

Motor mount kit voltage question

dev/nulldev/null Posts: 381
edited 2009-06-22 00:54 in BASIC Stamp
Hi an thanks for a great forum at Parallax!

I recently ordered the "Motor Mount Kit", which has 12V motors.

I have a battery pack with 14.4V. Can I put this directly to the kit or do I need a voltage divider. If I need a voltage divider, what resistors should I use?

Thanks

Comments

  • GiuseppeGiuseppe Posts: 51
    edited 2009-06-21 21:35
    The motors will still work a 14.4v (DC i am assuming) if the are rated for 12v but it is better if you just stay with in the specs of the motor. You could use a voltage divider but it is much easier to simply use a 12v regulator. http://www.radioshack.com/product/index.jsp?productId=2062600 you could go to radioshack and buy one if there are no other electronic shops around you. These can handle up to one amp so you have to make sure your motor(s) do not exceed that rating. Another thing you can do is actually get several diodes (at a ampere rating that matches your motors of course) and wire them in series along with your 14.4v battery pack. This works because diodes cause a voltage drop ( around .5v to .7v). So it would take about 5-6 diodes. Just remember, no matter what method you about doing, make sure it can handle the load (amperes)!
  • GiuseppeGiuseppe Posts: 51
    edited 2009-06-21 22:15
    I actually just took a look at the motors you are taking about, says here ~190 RPM @ 14.5 VDC, 1.60 A, no load. Your fine with no additional circuitry unless you want less torque. Just plug in and go, just make sure your batteries can put out that much current.
  • ercoerco Posts: 20,259
    edited 2009-06-22 00:54
    Never use resistors to adjust motor speed, that's·incredibly·inefficient and you lose motor torque at low RPM.

    Sounds like your plan is to just switch the motors on & off, perhaps with simple transistor switches or relays. They'll work, and shouldn't burn up at 14 volts, but you'll find out pretty quickly that on/off switching is not useful for any precision motor control for maneuvering. If that's your goal, you'll end up springing for a PWM motor speed controller pretty quickly, so add that to your budget.

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    ·"If you build it, they will come."

    Post Edited (erco) : 6/22/2009 12:59:19 AM GMT
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