Hi. I am trying to reduce rpm on a AC 1000rpm motor. Is there a way to do this? I want 210 rpm output.?
Put a rheostat on it, kinda like a light dimmer.
What you need is a circuit to reduce the percent of the output waveform applied to the ac motor. That will slow down the motor, but I hope you don't want a lot of power. That much chopping will make the motor not be efficient. Talk to some of your geek friends and I think they will be able to help.
Many AC motors are designed to run synchronously with the sinusoidal waveform of the AC line voltage, at a specific voltage and frequency. If the motor is operated outside of this range, it may run at a different speed, but its life will likely be shortened substantially by overheating or bearing failure, and it will run at low efficiency, and with poor torque output. A 5:1 speed reduction for any design of AC motor is quite a large reduction to achieve directly, via electronic control, simply due to cogging effect. Some designs of DC motors can achieve such speed ranges, with good efficiency and torque delivery, but with the added complexity and inefficiency of a suitable DC power supply. A hybrid of AC and DC motors, called a universal motor, is often used as the basis of household appliances, and these type motors can be speed controlled effectively, using rheostats or electronic speed controls. The usual means of changing a synchronous AC motor's delivered speed is to rewind it for operation at the desired speed (which may or may not be possible with the particular motor you have, depending on its rotor/stator design), or more generally, to use some kind of intermediary transmission to do the speed reduction. This latter means also provides for torque multiplication at lower speed, and allows the motor to work efficiently in the speed range for which it was designed.
You can by reducing the current with a rheostat but I wouldn't do that because you may burn up the motor, it needs to spin at 1000 rpm to properly cool itself. Dropping it down that far would not be kind to it. What you need is some type of gear reducer between the motor and whatever you are driving.
