Designers dealing with Universal Motors widely found in domestic appliances such as vacuum cleaners, washers and food processors have to choose between different speed control techniques for these motors. Many aspects of the motor such as size, cost, noise and efficiency are affected by the type of motor drive involved. Today, motor-control devices utilize electronic control making them progressively smaller and more-efficient with many added benefits such as energy savings and flexible interfaces.
Let’s walk through some reference designs that discuss efficient methods to drive universal motors along with complete documentation:-
- Low Cost Home Appliance Motor Control: Zilog offfers a reference design for speed control of universal motor for home appliances and industrial automation which requires minimum external components and firmware development. This is possible by utilising a Z8 Encore 8-pin MCU optimised for motor control. The MCU’s wide array of innovative, integrated digital and analog modules result in optimized control of the motor speed along with fault protection during an overload condition. Battery operation helps to add portability to the design. More on this Reference Design
- Low-cost Universal Motor Drive: This is a low-cost universal motor chopper drive for home appliances such as vaccum cleaners, washers, hand tools, and food processors. The system uses a microcontroller from Motorola, a IGBT and an ultra-fast soft diode. The design uses a regulated speed and closed loop mode with a speed sensor on the motor shaft. More on this Reference Design
- High-efficiency Universal Motor Chopper: This reference design from Freescale presents a low-cost, open loop universal motor chopper control drive system for applications such as washing machines, vacuum cleaners, food processors, dishwasher and single-phase variable-speed drives. The design is based on the MC68HC908QT4 microcontroller, an IGBT (Insulated Gate Bipolar Transistor), and an ultra-fast high voltage (freewheeling) diode. Compared to a phase angle drive, the advantage of the chopper drive is higher efficiency with less acoustic noise and better EMC behavior. More on this Reference Design
- Low-cost Vaccum Cleaner Motor Controller: Here is a design from NXP which discusses a low cost vacuum cleaner system based on microcontroller P89LPC901 from Philips. Design hardware and software are fully discussed. This system can also guide the design of other universal motor driving systems that need robust controlling and harmonic suppression. More on this Reference Design