SU1287248A1 - D.c.electric drive - Google Patents

Abstract

The invention relates to electrical engineering and can be used in actuators of various devices. Reliability and reduction of power consumption of the device for starting a DC motor according to the principle of time and speed is achieved by switching on the winding 6 of the accelerator contactor using the thyristor 5, the thyristor 5 is controlled via the first IO capacitor from the capacitor 9 of the integrating RC circuit or via the second dynistor 14 from divider 12-13 eg. wages, summed to the koryu 2 electric motor. This allows the use of a contactor with a tripping voltage calculated for the terminal voltage of the power source AND motor. 1 il. (P

Description

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The invention relates to electrical engineering and can be used in actuators of various devices in which the load on an electric motor shaft can be varied.

The object of the invention is to increase the reliability of the device and reduce energy consumption.

The drawing shows a schematic diagram of a direct current drive.

The DC electric drive contains the first closing contact 1 of the linear contactor, the switch 2. of the electric motor, the starting resistor 3 and the second terminal of the contact 4. of the linear contactor in series. Parallel to Korya 2, the electric motor and the starting resistor 3 are connected in series to the thyristor 5 and the coil 6 of the accelerator contactor, the closing contact 7 of which bypasses the starting resistor 3, and the integrating RC circuit formed by the resistor 8 and the capacitor 9, which output through the first dinistor 10 and the disconnecting contact JI of the accelerator contactor is connected to the control electrode of the thyristor 5. The direct current drive also contains a voltage divider connected in parallel to the motor 2, formed by resistors 12 and 1 and the second dynistor 14, the output of the voltage divider through the second dynistor 14 being connected to the junction point of the first dynistor 10 and the disconnecting contact 11 of the accelerator contactor.

The control circuit consists of the Stop 15 and Start 16 buttons connected in series, as well as the coil 17 of the line contactor, the blocking contact 18 of which is connected parallel to the Start button 16. A disconnecting contact 19 of the line contactor is connected to the capacitor 9 of the RC circuit, and current-limiting resistors 20 and 21 are shown in the dynistor 10 and 14 circuits.

The DC motor operates as follows.

When the closing contacts I and 4 of the linear contactor are switched on, the measles 2 of the electric motor is connected to the power source through the starting resistor 3 and the electric acceleration begins.

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thruster for rheostat characteristics. At the same time, the contact 19 of the linear contactor is opened and the capacitor 9 of the integrating RC circuit starts to charge through the resistor 8. During the acceleration process, the voltage at the terminals of the electric motor core 2 increases, and consequently, at the voltage divider (resistors 12 and 13).

If the load on the motor shaft does not exceed the nominal value, then after some time the rotational speed of the core 2 of the electric motor will reach the value at which the starting resistor 3 must be grounded. The voltage on the resistor 13 of the voltage divider will reach the value at which the second distor will turn on 14. The thyristor 5 will open and the acceleration contactor coil 6 will be under full supply voltage. The acceleration contactor will operate, and the starting resistor 3 will be shunted, after which the electric motor will operate on a natural characteristic.

If the load on the motor shaft exceeds the nominal value. Kie, then the rotational speed of the core 2, and, consequently, the voltage on its terminals, may be insufficient to turn on the second dynistor 14; however, after the time specified by the parameters of the integrating RC circuit, the voltage on the capacitor 9 will reach t the inclusion of the first dynistor 10. The thyristor 5 will open, the acceleration contactor will operate, and will bypass the starting resistor 3.

When the line contactor is disconnected, the capacitor 9 is discharged through the opening contact 19, after which the device is ready for restarting.

In this way, the reliability of the device is reduced and the power consumption is reduced, since the acceleration contactor coil is selected at the nominal voltage of the power source.

Claims (1)

Formula invented A DC motor containing series-connected first closing contact of line3 12872484 contactor, the throttle of the accelerator electric motor is connected to the body, the starting resistor and the second electrode of the thyristor, the contact contact of the linear contact is characterized by the fact that pa, connected in parallel with the corrosion protection reliability and reduction of the electric motor and the starting resistance of the power consumption, I will introduce in it the serially connected voltage divider and the second diristor and the accelerator contactor coil, and the divider nor, which closing contact is connected in parallel switched on Parallel to the starting resistor of the electric motor, and its output torus, as well as integrating RC-tO through the second dynistor connected to the point a circuit, the output of which is via the per-junctions of the first dynistor and the diffuser dynistor and the closing contact of the accelerator contactor.