Thread: How to step down 12VDC battery to 5VDC?

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Hello,

I'm working on another prop for this year's haunt. We are changing out haunt completely this year, and going with an insane asylum theme. Already have 7 new animated props made, but have an idea for another that I need some help with.

I need to use a 12V lawn mower battery to power a wiper motor, but I need the motor to run at the 5V speed. If you are wondering why I just don't use a 5V power supply (that I already have), it is because this prop will be moving, in a circle, and I can't have wires running to it.

Is there a simple way I can make a unit to step down the voltage from 12V to 5V? Tried to search but couldn't find anything. Sorry if I missed something.

Thanks in advance for your help.

Stacey

In this case, actually reducing the voltage will be overkill. At the current you're going to need to run that motor, you really don't want to use a standard linear regulator to reduce the voltage (those usually max out at 3-5A, and would need serious heatsinking). You could use a switching step-down regulator (doesn't need the huge heatsinking). But, again, because of the current you need, these would probably be more expensive than you're looking for.

I'd recommend just getting a DC PWM motor speed control. This rapidly pulses the voltage to the motor, and you can vary the % ON time vs. % OFF time. You're still pulsing 12V to the motor, but the *average* voltage (because of the varying % ON/OFF pulsing) is variable. This is a better solution than just a lower voltage, even if you didn't have the no-wires requirement. Here's an example of such a device.

- Hook

Looks like that would work. Thanks. After playing around with the prop yesterday, it looks like I might be able to run this motor at 12V. I experimented a little with sprocket/pulley diameters and with enough reduction, 12V will probably work.

Thanks for the help.

Stacey

Try a old ballast resistor off a Chrysler ignition system.. they are white ceramic thing used to cut the voltage to the coil. I think it cuts it down to around 6v and they are cheap and every part store has them.
http://www.google.com/search?hl=en&r...og&sa=N&tab=if

How about using a 6v battery, such as from a golf cart?

I use these adjustable regulators in my props where I have 12+v power but need lower voltages for other areas of the props: http://www.dimensionengineering.com/...FUW9zAodqHpHjw

The nice thing with these is that they are adjustable so you can set it to any voltage ranging from 1.25v up to 13v. Input range is 3v to 30v. They have definitely saved me from having to use multiple power supplies - power cords drive me crazy!

Joe