SU881959A1 - Device for control of single-phase induction electric motor - Google Patents

Description

(54) DEVICE FOR CONTROLLING A SINGLE-PHASE ASYNCHRONOUS ELECTRIC MOTOR

one

The invention relates to electrical engineering and can be used for starting and braking single-phase asynchronous low power electromotive devices.

Closest to the present invention, there is a device for controlling a single-phase asynchronous electrolyte with parallel-connected working and starting windings containing a starting capacitor, one of which is connected to the starting one. a coil, two oppositely connected diodes, an additional capacitor, shunted by a resistor, and one of the plates of which is connected to the cathode of the first diode (1.

However, the known device has low braking efficiency.

The aim of the invention is to increase the braking efficiency.

This goal is achieved by introducing a reed switch, a switching unit composed of three switches, and an additional switch into a known device for controlling a single-phase asynchronous electric motor.

a resistor, one of the terminals of the winding of the horn relay relay is connected to the common connection point of the cathode of the first diode, resistor, additional capacitor and fixed contact of the first switch of the switching unit. Another terminal of the reed switch winding is connected via a moving contact of the second switch of the switching unit to the common connection point of the second plate of an additional capacitor and resistor, the non-contact contact of the second switch of the switching unit is connected to the anode of the second diode and connected to the moving contact of the third switch of the switching unit through the locking contact of the reed switch ,

Claims (1)

5 connected to the working winding of the electric motor and to the common connection point of one of the plates of the starting capacitor, the starting winding and one of the terminals of the inserted resistor, the other side of which is connected to the other plate of the starting capacitor through the moving contact of the first switching diode, the cathode of the second diode and the fixed contact of the third switch of the switching unit are combined and connected to the network. The drawing shows a schematic of the device being offered. The device contains a switching unit with switches I, 2, 3 with which the operation of the winding 4 and the starting winding 5 through the starting capacitor 6 are connected to the power supply network, and the non-switching switching unit 7, consisting of two oppositely connected diodes 8 and 9, the electrolytic capacitor 10, shunted by resistor I, is connected in series with the diode 9 on the anode side through the contacts of the switch 2. A switch 12 of the reed switch 13 is connected to the terminals of the capacitor 10, which connects the anode of the diode 9 with a point and the starting capacitor 6 and the starting winding 5, which is connected to the working winding 4 via the contacts of the switch 3 in the working winding circuit. Starting capacitor 6 is connected to switching unit 7 via contacts of switch 1 and shunted by resistor 14 through contacts of switch 1. In the initial starting position, winding 12 is connected through switching contacts of bodies 2 to terminals of capacitor 10, capacitor 6 is bridged by resistor 14 through switch 1, the contacts of the reed switch 13 are open for starting 5 and the working 4 windings are connected in parallel by switch 3 in the working winding circuit. The device works as follows. When the induction motor is turned on (AD switches I, 2, 3, current 4 flows around the start winding 5 through the capacitor 6, the contacts of the switches 1, 2, 3 and the switching unit 7, while the positive half-wave of the winding 5 passes through diode 8, and negative through capacitor 10, switch contacts, diode 9. The motor starts up. After a period of time determined by the capacitance of capacitor 10, diode 9 is blocked by capacitor 10. At the same time, the positive half-wave of alternating current through diode 8 charges condensation or 6, which locks the diode 8, as a result, the current flows through the switching unit 7, and hence the starting winding 5 stops. The H. start is finished. When the H is disconnected, the winding 12 of the reed switch 13 through the contacts of the switches 1, 2, connects to the terminals charged capacitor 10. Condenser 10 is discharged to winding 12, E resulting in the contacts of the reed switch 13 closing and connecting in parallel the connecting windings 4 and 5 BP with switch 3 in the working winding 4 through diode 9 to the network. In this case, the windings flow around the rectified network current and the AL is intensively slowed down. At the same time, the capacitor 6 is discharged to the resistor 14. At the end of the discharge of the capacitor 10, the winding 12 is de-energized, the contacts 13 of the reed switch open, thereby disconnecting the windings 4 and 5 BP from the mains. The invention The device for controlling a single-phase asynchronous electric motor with parallel-connected working and starting windings, containing a starting capacitor, one of the plates of which is connected to the starting winding, two oppositely connected diodes, an additional capacitor, shunted by a resistor, and one of the plates of which is connected to the cathode of the first diode , characterized in that, in order to increase braking efficiency, a reed switch, switch block composed of three switches and an additional resistor, one of the terminals of the winding of the reed switch is connected to the common connection point of the cathode of the first diode, resistor, additional capacitor and the fixed contact of the first switch of the switching unit, the other end of the winding of the reed switch through the movable contact of the second switch; the common point of connection of the second plate of the additional capacitor n of the resistor, the inactive contact of the second switch of the switching unit is connected to the anode of the second diode and Through the closing contact of the reed switch is connected to the movable contact of the third switch of the switching unit connected to the working winding of the electric motor and to the common connection point of one of the plates of the starting capacitor, starting winding and one of the terminals of the inserted resistor, the other output of which is through the moving contact of the first switch of the unit switch is connected to another plate of the starting capacitor, and the anode of the first diode, the cathode of the second diode and the fixed contact, the third switch of the switch unit You are united and connected to the network. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 731537, cl. H 02 P 1/42, H 02 P 3/24, 1975. Vy