SU1249486A1 - Device for controlling electromagnet - Google Patents

Abstract

The invention relates to automation and can be used to control the electromagnets included in the electro-hydraulic distributors. The aim of the invention is to increase reliability. The device contains sources of nominal and forced voltage, a generator of relaxation oscillations, an electromagnet actuation control unit, an OR element, the first and second delay units, and the first and second keys. The invention makes it possible to increase the reliability of switching on an electromagnet and provides a forced voltage to its winding only when the electromagnet does not operate from a nominal voltage. 3 il. g (L IN9 4i; about 4 СХ) о

Description

The invention relates to automation, in particular, to devices for the automatic control of the operation of electromagnets, used in the composition of various drive mechanisms, for example, electrohydraulic distributors,

The aim of the invention is to increase the reliability of the device.

1 shows a functional diagram of the device; Fig. 2 is a block diagram of an electromagnet actuation control unit; FIG. 3 is a diagram of the operation of an electromagnet control device.

The device contains a source 1 of nominal non-contact, a switch 2, a winding 3 of an electromagnet, a control unit 4 of the operation of an electromagnet, an element OR 5, the first delay block 6, the first key 7, the second block 8 delay, a generator 9 of relaxation oscillations, the second key 10, source 1I forced voltage.

The electromagnet actuating control unit 4 consists of successively connected current sensors 12, an ac amplifier 13, a threshold device 14 and a two-bit counter 15 pulses with unitary coding (FIG. 2),

The device works as follows.

When the contacts of the circuit-breaker 2 are closed, the control signal from the source 1 of the nominal voltage goes to the key 7 and the winding 3 of the electromagnet (Fig. 3, diagram 1). The key 7 passes this signal to the input of the second delay unit 8, which starts timing equal to 1.1-1.3 times the normal operation of a controlled electromagnet. Under the influence of a control signal in the electromagnet itself, the process of its switching begins. At the same time, the type of the cur- rent of the current flowing through the electromagnet winding uniquely determines the process of its switching. In the case of normal operation of the electromagnet, the current Hgibakitz has a two-humped appearance, when it fails, the one-humped one. The control of the current envelope is performed by the current sensor 12 of the electromagnet actuation control unit 4. The signal from current sensor 12 after it has been amplified by amplifier 13 is supplied

five

five

5 0 5 0 5

The threshold device 14, which, in accordance with the number of humps of the envelope, generates counting pulses arriving at the input of a two-bit counter 15 pulses. In the normal operation of the electromagnet at the output of the second discharge of the counter 15, which is the WELLWARE of the electromagnet control unit 4., a signal is generated which, having passed through the OR element 5, is fed to the control input of the key 7. The latter actuates and removes the control signal from the input a second delay unit 8, which returns to the initial state. The remaining units and nodes of the device in this mode of its operation do not take part.

When the electromagnet does not operate from the nominal voltage, after a delay t of the second delay unit 8, a start signal is generated at the relaxation oscillator 9 operating in the standby mode and the first delay unit 6 (FIG. 3, diagram 2). The first delay unit 6 starts counting the time t determined by the maximum allowable power of the forced voltage supplied to the electromagnet (FIG. 3, diagram 4). The start of the relaxation oscillation generator 9 is characterized by the formation at its output of pulses with a duration tj equal to the response time of the electromagnet and a pause between them equal to the duration of the transient after the pulse is applied to the voltage (Fig. 3, diagram 3). These pulses arrive at the control input of the second switch 10, which, for the duration of their operation, connects the forced voltage source I1 to the winding 3 of the electromagnet (FIG. 3, diagram 5)

When an electromagnet is triggered by a forced voltage at the output of control unit 4, a signal is generated, which through the element OR 5 goes to the control input of the first key 7. Last activated, turns off the control signal from the input of the second delay unit 8, which returns to its initial state, remove the start signal from the inputs of the first block 6 of the delay and the generator 9 relaxation oscillations. The second block 6 delay also returns

3

c is returned to the initial state, and the generator 9 fails to generate, thereby disconnecting the forced voltage source I1 from the winding 3 of the electromagnet,

If under the action of forced voltage the electromagnet does not work, then after the time delay has elapsed. At the output of the first 6 delay unit, an control signal is generated, which, passing through the element OR 5, arrives at the control input of the first key 7 and the device returns to the initial state.

This cycle of operation of the electromagnet control device occurs each time it is turned on, i.e. each time a nominal control voltage is applied to its winding.

Claims (1)

Invention Formula A device for controlling an electromagnet, containing a source of a forged voltage, a first delay unit, a generator of relaxation oscillations, and a source of nominal // 49486.4 the voltage connected to the first output of the switch, connected by the second output to the output of the device, characterized in that, in order to increase reliability, the first and second keys, the OR element, the second delay unit and the response control unit are entered into it an electromagnet connected by the input to the input of the device, and an output to the first input of the OR element connected by a second input to the output of the first delay unit, and an output to the control input of the first key connected t5 by the first and second information outputs corresponding to the output of the device and the input of the second delay unit connected by the output to the input of the first delay unit and controlled by the 20 input of the relaxation oscillation generator, connected by the output to the control input of the second key connected to the first and second information outputs 25 of the rated voltage source and the forced voltage source, respectively. five figure 1