How to "slow" down a linear actuator?
I have a 12 volt linear actuator that travels too fast when it is engaged. What could I wire in-line to the actuator to vary the speed? A rheostat perhaps? I want to make sure that whatever it is does not cause the actuator to "burn out" prematurely, just slow its speed. I assume the voltage is proportional to the speed but I am not sure...
- 1 decade agoFavorite Answer
I did this before simply by putting a power resistor inline with the motor. Yes the speed is proportional to the voltage.
A rheostat is basically a variable resistor, so that should work too. This would give you variable speed too.
For the power resistor idea, you need to add around a 1 or 2 ohm resistor since motors have a very low resistance. The voltage will split between the two items. You can measure the voltage across the resistor and subtract that from 12 volts to see the new voltage on the motor, when the motor is running. Or you can measure it directly.
Make sure you monitor the temperature of the resistor that it doesn't get too hot. This is not really set up for continuous use, but you will need to do some testing before you see what the limits are.
You can buy the white power resistors at radio shack or find them in old electronics like monitors and tvs. Make sure they are completely discharged before you go poking around in them though. (see source)
There are also some heavy duty power resistors with aluminum cases, but they are probably too high of a resistance value for this project. (see source)
Another way to do it is with a mosfet speed controller. This would be the way to do it for continuous use, but it is a lot more complicated. (see source)
Hope this helps.Source(s): http://www.allproducts.com/ee/synton/09-cement_pow... http://www.made-in-china.com/image/2f0j00yejTUgZnE... http://homepages.which.net/~paul.hills/SpeedContro...