V is the supplied voltage, Eb is the back EMF, Ia is the armature current, and Ra is the armature resistance. Eb = (PøNZ)/60A. This implies three things: The speed of the motor is directly proportional to supply voltage.

## What determines the speed of a DC motor?

DC controls adjust speed **by varying the voltage sent to the motor** (this differs from AC motor controls which adjust the line frequency to the motor). Typical no load or synchronous speeds for an AC fractional horsepower motor are 1800 or 3600 rpm, and 1000-5000 rpm for DC fractional hp motors.

## Which parameter controls the torque of a DC motor?

Here, again, the torque of a dc motor (usually a permanent-magnet or a shunt type) is controlled independently of speed. This is achieved with **current feedback**.

## Which parameters are responsible for speed change of motor?

**Speed, torque, and horsepower** are three inter-related parameters in motor control. The speed of a motor, measured in revolutions per minute (rpm), defines a motor’s ability to spin at a rate per unit time.

## What is the maximum speed of DC motor?

The nominal maximum speed and power are **24000 RPM and 0.815 HP**. In particular, these machines must operate loaded in order to avoid damage.

## How can we reduce rpm of DC motor?

**A couple of things you can do:**

- Use gears to change ratio of speed, which is what you’re going to do. …
- Use a stepper motor, which are commonly used for high-torque, low RPM applications.
- Find some sort of PWM control circuit to slow it down, although you probably won’t be able to get it down to 5-10RPM.

## What are the factors affecting torque in DC motor?

Speed Variation

Output torque of a DC motor is proportional to the **product of the main pole flux, armature current, and a machine constant that is a function of armature windings**. Therefore, with armature voltage speed control and constant shunt field excitation, the torque is dependent upon the armature current only.

## How does DC motor increase RPM?

By **increasing** the voltage of the armature, it produces more magnetic forces to overcome the field magnet, **increasing** the **rpm**. By **increasing** the field current, more magnetic fields opposing the motion are produced, at the same time more cemf is produced reducing the armature voltage, decreasing the **rpm**.