Brushless dc (BLDC) motors differ from brush-type dc motors in that they employ electronic (rather than mechanical) commutation of the windings. BLDC motors are highly efficient, delivering more energy per unit when compared to brush-type DC motors. They are growing in popularity due to the world’s need for greater energy efficiency. BLDC motors use electronic commutation versus mechanical commutation in brush-type DC motors to control the power distribution to the motor. Latching Hall-effect sensors are used to measure the motor’s position, which is communicated to the electronic controller to apply energy to the motor at the right time and right orientation. BLDC motors can be used in any application that needs an efficient and quiet motor, ranging from robotics and portable medical equipment to HVAC fans and appliances.
Honeywell offers several Hall-effect sensor ICs that provide high magnetic sensitivity of 30 Gauss (G) typical (55 G maximum) over the temperature range of -40 °C to 150 °C [-40 °F to 302 °F] without chopper stabilization of the Hall element. Combined with a faster latch response time and the capability to handle higher frequencies, these latching Hall-effect sensor ICs significantly contribute to higher motor efficiency. Initial customer feedback indicates a five percent increase in motor efficiency when compared to a competitive chopper-stabilized part.
Latch on to an initial pole (North or South) until a magnetic field of sufficient strength of the opposite polarity is brought near the sensor IC.