Unlike the pre-set speed control, variable control allows a greater variation in motor speeds. The motor is a plain AC series-wound brush motor and consequently it is incapable of any variation in speed on its own.
Speed is governed by a separate speed control unit. This unit consists of a printed circuit board with a number of solid-state components, often called the speed module or motor control module. In simple terms, this device interrupts the power supply to the motor at regular intervals. In effect, it pulses the motor. If the pulsing is increased, the motor will run faster and if pulsing is slowed, the motor will run slower. Read the rest of this entry »
The electric food mixer is truly a labour-saving appliance. Many variations can be found from the simple hand-held type to the large table-top version with additional attachments, such as juice extractor, liquidizer, vegetable peeler, can opener and grinder.
At the heart of all mains powered mixers is a series-wound brush-gear motor. This type of motor is used because of its good power output (up to 3hp on large table-top models) combined with the capacity for variable-speed control. These two advantages make this aversatile appliance. Read the rest of this entry »
There is what seems to be an ever-increasing range of labour-saving equipment capable of tackling the wide variety of repair and building work now taken on by the D-I-Y home-owner. Tools that were once used in only professional workshops and factories are now quite commonplace around the house. Electric drills, routers, grinders, saws and planes are now produced to meet the demand from the rapidly increasing army of D-I-Y enthusiasts. The diversity and range available is vast. They are all based on an electric motor taking the place of manual effort. Each has a powerful motor for direct drive or reduction via a gearbox or electronic control and can be found in mains or battery powered versions in most instances. Read the rest of this entry »
