Basic Electronics and Electrical tutorials: Domestic use of motors

Domestic use of motors

Introduction:-

Small size dc motors, brush less dc motors and steeper motor are used in various equipment. In computer and laptop small size brush less dc motor is used for running CPU and power supply cooling fan. In cd drive and dvd drive small size brush less dc motor is used for disc rotation.Small size dc motor is used for disc trey movement system. A small steeper motor is used for precise movement of lens system. In printer brush less dc motor and steeper motor are used for roller and printer head movement. Steeper motor are used in three d printer as well. Record players of old time uses single phase shaded pole motor of very small size. Three/four speeds were achieved by using stepped pulley. tape recorder were using small 6 volt dc motor.

small dc motor

brush less dc motor

steeper motor

Single phase motors

Single phase motor of different types and speeds are used in different appliances. A small 4 pole 1450 rpm capacitor motor is used in a table fan. Some small fan like cabin fan uses single phase shaded pole motor . Shaded pole motors not required capacitor. Simple tullu pump motor used in coolers are small shaded pole motor. The main fan motor used in coolers are kit fan motor normally 150 watt triple speed motor.It has three speed winding run at high medium and low speed with the help of speed changing switch. in addition to this exhaust fans are also used. These motors are of 1450 rpm 4 pole motor or 950 rpm 6 pole motor. 6 pole 950 rpm motor has less operating sound as compared to 4 pole 1450 rpm motor. Exhaust fans are size wise come in 12, 15, 18, 24 inches. but normally 18 inches are used in window coolers. Washing machine also use single phase capacitor motor one for drum rotation and other for dryer rotation. Speed control and timers are used for different washing cycles. In automatic machine micro controller, digital display and key pad are provided to operate machine in different washing mode. Ceiling fan motor is also split phase capacitor motor. in this outer body work as rotor. fan blade or fixed on outer body. the motor is generally 14 pole or 12 pole. 48 inches fan runs at 470 rpm whereas 56 inches runs at 390 rpm.
AC:- In air conditioner three motors are used. first one is heavy compressor motor sealed within compressor unit. It is capacitor motor.It run compressor to compress refrigerant vapor. Second one is condenser cooling fan motor. It is also capacitor motor approximately of 250 watt 1450 rpm. Some AC uses double speed motor in condenser cooling fan. These two motors are fixed in out door unit in split ac. where as fixed in outer side area of window ac. Third motor is blower fan motor 3 speed motor. It is simple capacitor motor with three or four speed winding as the design of AC. In window ac there is only one motor for condenser cooling fan and blower fan. This motor has double ended shaft. Motor is fixed in center. Condenser cooling fan is fixed on outer side shaft end whereas the blower fan is fixed on inner side shaft end. Here the speed of condenser fan is also changes with blower speed setting. Some cooler also have single motor with double ended shaft one side for fan and other side for pump.
Mixer grinder/ sewing machine/ hand drill machine uses single phase universal motor (ac dc series motor) it run at 5000 to 6000 rpm as per design of motor and load condition.This motor is 2 pole ac dc series motor. It has 2 pole field winding with three speed tapping, a armature and 2 carbon brushes. Armature winding trough carbon brushes, field winding, thermal cut-off and speed selector switch all are connected in series.