SU1397883A1 - Device for monitoring electromagnet performance - Google Patents

Abstract

The invention relates to automatic control and is intended to control the operation of electromagnets that do not have their own I V Ug contact groups according to the nature of the current in the field winding. The purpose of the invention is to expand the functionality by determining the time from the moment of operation of the electromagnet to the moment of release. The device contains There is a current sensor 5, to the output of which a differentiating amplifier 12 is connected, the output is connected to the inverter's inverse of the comparator, the output of which is connected to different trigger inputs 7 through element 9 and OR-NOT 10. the duration of which corresponds to the time from the moment of the electromagnet to the moment of release. 2 Il. yu (L

Description

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areas of positive voltage. Prior to this, the moment of the first input of the element 9 was already present at the positive voltage UBX from the bus 1. When a positive voltage arrives at the second input of the element 9 and a positive voltage is generated at its output, from which the trigger 7 is activated and at output 8 a high positive voltage is generated.

After the core stops (time tj), the current in winding 2 rises again, the voltage from the output of comparator 11 and element 9 becomes zero, and trigger 7 maintains its state.

At time t, the voltage on the input bus 1 becomes equal to zero, the current in the winding 2 of the control of the electromagnet 3 begins to decrease, the voltage from the output of the comparator 11 is formed by a high positive polarity, and the voltage from the output of the OR-NOT element remains zero. and trigger 7 maintains its previous state. Due to the fact that the inductance takes place in the control winding 2, then when the voltage is removed through the winding 2, it cannot instantly change, therefore, starting from the time t, it gradually decreases, but the electromagnet measles will remain motionless for some time.

At time t, the current in the control winding 2 decreases to such an extent that, under the action of the return spring, the measles begin to move in the direction of returning to the initial state.

Automatic control to control the operation of electromagnets that do not have their own contact groups according to the nature of the current in the field winding.

The purpose of the invention is to expand the functionality of the device by allowing the formation of a pulse, the duration of which corresponds to the time interval from the moment the electromagnet is triggered to the moment it is released.

Figure 1 shows the functional-15 on the device; figure 2 - the timing diagram of his work.

The device contains a power supply bus 1, a winding 2 of the electromagnet 3, a shunt diode 4, a current sensor 5, a common bus 20, a trigger 7, a first device output 8, an AND 9 element, an OR-NOT 10 element, a comparator 11, a differentiating amplifier 12 including resistor 13 and capacitance 14.

The device works as follows.

At the time of the absence of voltage, bus 1, voltage from current sensor 5 and at the output of comparator 11, element 9 AND and trigger 7 are zero.

The voltage from the output of the element 11 OR-NOT 10 is high; it enters the input of the trigger 7 and sets it to the initial state at which the voltage at its output is zero.

After voltage U is applied to bend 1 (time t,), a current builds up through the coil 2 of electromagnet 3, and a counter-emf is induced in proportion to it to 40V winding 2

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the voltage on the current sensor 5 rises.

At time t, the current in the control winding 2 reaches the value at which the electromagnet measles starts to move. During the time of movement of the core, the air gap between the magnetic conductor and the electromagnet core decreases, the flux coupling (magnetic flux) in the magnetic circuit increases, and, as a result, a anti-EMF is applied to the winding 2 acting in the opposite direction of the main voltage, as a result the current in the winding 2 and the voltage at the output of the sensor 5 decrease. At the time t, the voltage decreases on the current sensor 5 at the output of the comparator 1 1 (a high

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during the time of movement of the box. This counter-emf increases the current in the control winding 2 and the voltage on the current sensor 5.

At time t, y, the voltage at the output of the cocktail 11 becomes equal to zero, the element OR-NOT 10 is triggered, the output of which produces a high voltage, and the trigger 7 returns to its original state, and the output 8 forms the trailing edge of the output pulse, the duration of which strictly equal to the time from the time tj to the time tg.

Claims (1)

Invention Formula A device for controlling the operation of an electromagnet, containing a current sensor, the first output of which is the first input of the device and connected to the first input of a differentiating amplifier, the output of which is connected to the inverse of the comparator, a trigger, the forward output of which is the first output of the device, the power supply bus connected directly to the first input and the second output of the device, and through a shunt diode to the common bus connected to the second the output of the current sensor, the second input of the differentiating amplifier and the direct input of the comparator, characterized in that, in order to expand the functionality of the device, the elements AND and OR-NOT are entered into it, the first inputs of which are connected to the power supply bus, the second inputs to the output comparator, and the outputs are connected respectively with the R-inputs of the trigger.