# Your question: Can you make an electric motor variable speed?

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No. Some motors cannot change their speed at all – steppers, induction motors and synchronous motors. Some motors require different speed control techniques – brushless DC, and many others. Variable speed drive can only be used with Squirrel cage induction motors due to their poor starting torque.

## Can a single phase motor be variable speed?

Speed control of single-phase induction motors is desirable in most motor control applications since it not only provides variable speed but also reduces energy consumption and audible noise. … Using microcontroller-based control systems, one can add speed variation to the system.

## How do you control the speed of an electric motor?

Thus, the speed of a DC motor can be controlled in three ways:

1. By varying the supply voltage.
2. By varying the flux, and by varying the current through the field winding.
3. By varying the armature voltage, and by varying the armature resistance.

## Can you put a rheostat on any electric motor?

If using a rheostat for motor control it is essential to understand that all types of direct current motors could be speed-controlled, however, a small amount of AC motors are controllable with rheostats. … The smaller sized rheostats have screw-driver slots that make for easy adjustments.

## Can I use a potentiometer to control AC motor speed?

Brushed DC or universal can be controlled with a potentiometer. AC and brushless DC motors can’t be controlled that way. They require a change in frequency, not a change in voltage. If the motor is single phase, with a starting winding, and you are using a frequency varying controller, you can’t vary things that much.

## Can any DC motor be variable speed?

A: In general if you don’t do anything special to it, a DC motor will have variable speed. The main factors are the DC voltage applied to the armature coil and the amount of torque load you are trying to drive. In order to make it into a constant speed DC motor you have to have some sort of electronic feedback.

## Can AC motors be variable speed?

Variable speed requirements for AC induction motors are typically fulfilled by a 3-phase motor and an inverter or VFD. … At 60 Hz, the motor will run at 1800 RPM. A variable frequency drive controls the motor speed by using PWM (Pulse Width Modulation) to alter the power supply frequency that’s fed to the motor.

## Can you put a dimmer switch on an electric motor?

The best dimmers for running an electric motor have an adjustable minimum speed setting. … Always buy a switch that is rated to handle an equal amount for the watts or more, not less, in order for the dimmer switch to work well. A dimmer motor AC switch is suitable for a ceiling fan.

## How do you control the RPM of a single-phase AC motor?

SINGLE- PHASE AC MOTOR SPEED CONTROLS

The two primary ways to control the speed of a single-phase AC motor is to either change the frequency of the line voltage the motor sees or by changing the voltage seen by the motor, thereby changing the rotational speed of the motor.

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## Can I use a light dimmer to control a motor speed?

No you can’t use a dimmer switch to control a DC motor. A dimmer uses diac and triac and only works with AC which commutates the triac OFF at the end of every half cycle.

## Can you speed control a PSC motor?

The 770-PSC Control offers a way to add existing single phase PSC or shaded pole motor fans to a building automation system. The 770-PSC control measures the motor’s RPM, using an easy to attach sensor, and can adjust the motor’s speed to match a chosen set point. … There are two modes of motor speed control available.

## How do you slow down a 240v motor?

With a Shaded Pole motor, you can simply reduce the voltage, say with a light dimmer and the motor produces less torque, then with less torque the air friction on the fan blades causes it to slow down, which in turn moves less air.

## Can I put a VFD on any motor?

Output voltages are available for VFDs to match almost any existing motor voltage. However, very few, if any, VFDs have a direct 13,800-volt output for very high-voltage motors. For these cases, using a step-up transformer on the output of the VFD is often necessary to match the motor voltage.