Where are universal manifold engines used and how are they arranged?

Purpose of collector engines

Universal collector motors are used in industrial and household electrical installations (electrified tools, fans, refrigerators, juicers, meat grinders, vacuum cleaners, etc.). They are designed to work both from a direct current network (110 and 220 V) and from an alternating current network with a frequency of 50 Hz (127 and 220 V). These motors have high starting torque and are relatively small in size.

The device of collector electric motors

In terms of construction, universal collector motors do not fundamentally differ from series-excited two-pole DC motors.

In universal collector motors, not only the armature is drawn from sheet electrical steel, but also the stationary part of the magnetic circuit (poles and yoke).

The field winding of these motors is included on both sides of the armature. Such inclusion (balancing) of the winding allows to reduce the radio interference generated by the motor.

The torque is created due to the interaction of the current in the armature winding (rotor) with the flow of the magnetic field.

Technical characteristics of collector engines

These engines are produced at relatively low powers. — from 5 to 600 W (for power tools — up to 800 W) at a speed of 2770 — 8000 rpm. The starting currents of such motors are small, so they are connected directly to the network without starting resistances. Universal read motors have a minimum of four wires: two for AC mains and two for DC power.

The efficiency of the universal motor in alternating current is lower than in direct current. This is due to increased magnetic and electrical losses. The amount of current consumed by a universal motor when operating on AC is greater than when the same motor is operating on DC because alternating current in addition to the active component, it also has a reactive component.

Speed ​​control of the collector electric motors

The rotation frequency of such motors is adjusted by changing the supply voltage, for example autotransformer, while low power motors — rheostat. A single-phase collector motor should not be started on the stroke under light load because it may "leak".