SU372629A1 - ALL-UNION [ - Google Patents

Description

one

A device for reversing a two-point direct current electric motor is known, comprising two limit switches installed in the extreme positions of the driven mechanism and two switches installed in control points.

In the known device, the reversal is carried out by means of intermediate switching devices controlled by switches.

The purpose of the invention is to simplify the known device by eliminating intermediate switching devices.

This goal is achieved by the fact that the switches are bipolar, the first pole of the power supply circuit is connected to one of the common positions of the first switch outputs, and the second pole is connected to the other common terminal of the first switch, the positional terminals of which are connected to the positional terminals of the second switch with normally closed contacts of limit switches whose normally open contacts are connected to the second pole of the power source.

The drawing shows a circuit diagram of a device for reversing a low-power direct-current electric motor with excitation from permanent magnets.

The circuit breaker / power is supplied to the circuit. The reversal is controlled by switches 2 and 3 located at two different points.

The common for the positions of the leads of the first switch 2 are connected to the power source, and the positional leads of this switch are connected to the positional leads of the switch 3. The common leads of the switch 3 are connected to the limit switches 4, 5 in the core 6 circuit.

The drawing shows the state in which the contacts of the limit switches 4 and 5 turned out to be after the motor had been worked out when setting switch 2 to position a. To make the circuit easier to read, let's call the switch contacts 2

and 5, drawn under each other - of the same name, and crosswise lying - unlike.

When switching switch 2 to position b, the current from the supply mains positive passes

through the opposite contacts of switches 2 and 3 to the normally closed (NC) contacts of the limit switch 4 and further to the left brush core 6. Minus power to the right brush is fed before moving the motor through the normally open (HP)

short-circuited limit switch 5. After moving. motor and release the limit switch 5 minus power is supplied to the right brush through the NC contact of the same limit switch and then through the opposite contacts of the switches 5 and 2.

Upon completion of the development of the electric motor, the limit switch 4 opens its NC contacts and closes the HP contacts. The main circuit is open and prepared for reverse. When the switch 2 is moved again to the position a, the current from the power supply network through the contacts of switches 2 and 3 of the same name will go to the right brush box 6 through the NC contacts of the limit switch 5, and the power supply minus goes to the left brush through the HP contacts of the limit switch 4, while it is pressed, and then after it is released through the NC contacts of the limit switch 4 and then the like contacts of the switches and 2, i.e. the motor is reversed. With a fixed position switch. 5 Shifting switch 3 ensures that the control of the reverse of the electric motor is fully identical to that described above.

Using the proposed device, it is possible to control the reverse of an electric motor with various excitation systems. For a motor with parallel excitation, the field winding should be

attached behind a security guard. For a motor with sequential excitation, one end of the field winding must be connected to the terminal of switch 2 to which the power supply minus is connected in the drawing. The second end of the field winding is connected to the power supply minus of an electric motor with independent drive. The field winding is connected to an external power source.

Subject invention

A device for reversing a two-point direct current motor containing two limit switches installed in the extreme positions of the driven mechanism and two switches installed in control points, characterized in that, for the sake of simplicity, the switches are bipolar, the first pole of the power supply circuit is connected to one of the common positions of the pins of the first switch, and the second pole to the other common pins of the first switch, the positional pins of which are connected to the positional pins There is a switch having common terminals connected to normally closed contacts of limit switches, normally open contacts of which are connected to the second pole of the power source.