SPEED ADAPTER OF ASYNCHRONOUS ELECTRIC MOTOR Russian patent published in 2017 - IPC H02P25/02 H02P27/04 

FIELD: electricity.

SUBSTANCE: device contains an asynchronous electric motor (1) with a bridge joint of power keys (2, 3, 4), a low-power (1 watt) DC motor (5) with a permanent magnet rigidly fixed to the rotor (9). Doubled Hall sensors (6, 7, 8) are placed around the DC motor (5) radially at equal distance from each other (in a circle through 120 degrees). The doubled Hall sensor consists of two Hall sensors located one above the other. The Hall sensors in each pair are turned on 180° relative to each other. The sensors simultaneously fall under the action of a magnetic field and being directed to the magnetic field by different sides, operate in turn: when the magnetic field changes, the state of the Hall sensors changes from open to closed and vice versa. The Hall sensors control the keys of the three-phase bridge joint (2, 3, 4) via the control bus. The keys (2, 3, 4) form a three-phase alternating current, which is fed through the power bus to the windings (L1, L2, L3) of the three-phase asynchronous electric motor (1). The variable resistor R in the DC motor feed circuit (5) serves to smoothly adjust the speed of the electric motor (5), which leads to a change in the frequency of the alternating current and, consequently, to a change in the speed of rotation of the asynchronous electric motor.

EFFECT: providing a smooth adjustment of the rotation speed of the asynchronous electric motor from minimum speed to the maximum possible speed with a high efficiency of the device.

3 cl, 2 dwg