Open Loop Universal Motor Reference Design Chopper Based on the MC68HC908QT4 Manual Microcontroller

This circuit describes the design of a low-cost chopper motor control drive system based on the MC68HC908QT4 microcontroller, an IGBT (Insulated Gate Bipolar Transistor), and an ultra-fast high voltage (freewheeling) diode. This low-cost single-phase power board is dedicated to universal brushed motors. The operational mode used in this application is open loop and regulated input motor voltage. The type of motor and its drive have a high impact on many home appliance features, such as cost, size, noise and efficiency. The electronic control usually becomes necessary when variable speed or energy savings are required. This circuit also explains how to design the software implementation using an M68HC08 family microcontroller. A low-cost microcontroller, such as the MC68HC908QT4, is powerful enough to handle the workload necessary for driving a closed loop chopper drive.

This reference design features TE connector 1217080-1 that can be used in different application such as, washing machines, vacuum cleaners, hand tools, food processors, dishwashers, single-phase variable-speed drives and low-cost, medium-power applications variable voltage output.