Brushless Dc Motor Speed Control Circuit Design

A brushless dc electric motor bldc motor or bl motor also known as electronically commutated motor ecm or ec motor and synchronous dc motors are synchronous motors powered by direct current dc electricity via an inverter or switching power supply which produces electricity in the form of alternating current ac to drive each phase of the motor via a closed loop controller.

Brushless dc motor speed control circuit design.

The above conditions initiates the oscillation cycle making the output change to a logic high. This design has 2 inputs to control motor speed and direction. A low end esc can be had for less than 10. A quick review of brushed and brushless dc motors.

You can observe the components used to implement this circuit in above figure wherein the system uses a power supply circuit to power the entire circuit a user input interface and a controller circuit to program the. Are you fed up with ordinary pwm circuits which do not provide perfect dc motor speed control especially at lower speeds. The main block diagram and typical application circuit are shown in figure 3 and figure 4 respectively. The speed is controlled through an externally applied varying dc voltage source.

Typical application circuit. Pwm dc motor control with ic 555. There is even a controller with independent voltage and speed controls so you can discover your motor s char acteristics empirically. Brushless dc bldc motors have become extremely popular over their predecessor the brushed dc motor see figure below.

As the international energy agency reports that 40 of all global electricity is used to power electric motors such efficiency gains become compelling. An esc electronic speed control is a circuit for controlling an electric motor particularly brushless dc motors. Brushed dc motors use brushes and a. The resistive divider may be appropriately dimensioned for enabling an over current protection and control over the connected bldc motor.

As the name implies brushed dc motors use brushes and a commutator for controlling the movement of the motor s rotor. The code in this application note was developed with the microchip pic16f877 picmicro. Initially when the circuit is powered the trigger pin is in a logic low position since the capacitor c1 is not charged. Several controllers for brushless motors.

Then check out this outstanding single chip pwm motor speed controller circuit that will give you a complete 360 degrees of continuously varying motor speed control right from zero to maximum. Electronic commutation provides greater efficiency over conventional dc motors with improvements of 20 to 30 for motors running at the same speed and load. This system is implemented to design a brushless motor controller to provide precise and efficient speed control of the motor. The second circuit which forms the main driver configuration for the proposed 3 phase brushless bldc motor driver circuit could be also seen having a current sensing stage across its lower left section.

Designing the 3 phase brushless dc motor.