JPH0729605U - Constant amplitude control circuit for electromagnetic vibration equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] To enable constant voltage control with little increase in cost using a conventional constant amplitude control circuit. [Structure] Secondary side 105a of transformer 105 of control power supply of control circuit 300 including thyristor phase control circuit 19
A small signal thyristor 29 is connected to the gate terminal, a gate pulse is supplied to the gate terminal from the output terminal of the thyristor phase control, and the current flowing through the small signal thyristor 29 is rectified by the resistor 31 and the capacitor 32. This is the amplifier 5
The voltage is supplied to one input terminal of the comparator 15 by switching the changeover switch 102 via 5.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a constant amplitude control circuit for an electromagnetic vibration device.

[0002]

[Prior art and its problems]

 As an electromagnetic vibration device, for example, an electromagnetic vibration feeder is widely known, but the transfer speed of powder particles due to the vibration increases in proportion to the amplitude of the trough as its movable part. The trough amplitude must be constant to keep the transfer rate constant. However, if the load of the trough fluctuates or the voltage applied to the electromagnet coil of the drive section fluctuates, the swing of the trough naturally fluctuates, and the transfer speed of the granular material also fluctuates. Therefore, in order to make the transfer speed constant, for example, a constant amplitude control circuit as shown in FIG. 5 is used.

In FIG. 5, the trough 3 of the electromagnetic vibration feeder F is vibrated by the driving unit 3a including an electromagnet coil, and the amplitude detection element 4 is attached to the trough 3, which has a constant amplitude. The voltage is supplied to the sensor input terminal 6 of the control circuit 1 and from there to the one input terminal of the comparator 15 via the amplifiers 7 and 9, and the other input terminal is supplied with a voltage corresponding to the amplitude setting value. Are supplied through the swing setting volumes 34, 21. The output of the comparator 15 is supplied to the thyristor phase control circuit 19 via a proportional (Proportional) control circuit 16 and a multiplier (Integrator) 17, and the gate pulse as the output thereof is the gate terminal of the large current control thyristor 2. To be supplied to the AC power source and thus the amplitude of the trough 3 of the electromagnetic vibration feeder F 1 connected to the AC power source is controlled to be constant.

In addition, in the figure, 41 is a disconnection detection circuit, 42 is a flip-flop circuit, and 52 is an AND gate. When a disconnection is detected, the flip-flop circuit 42 produces an output at the Q output terminal, which causes an AND gate. The operation of the thyristor phase control circuit 19 is stopped via 53.

Further, in the constant amplitude control circuit of FIG. 5, the output of the integrator 17 is supplied to the manual contact via the amplifier 55, and the changeover switch or the movable contact 13 can be manually switched. I am trying. As a result, almost constant amplitude control can be performed without using the amplitude detection element 4. However, the proportional control circuit 16 and the integrator 17 are set so that the difference of the comparator 15 becomes zero. Since it operates, the gate pulse of the same phase is eventually supplied to the gate terminal of the large current thyristor 2. Therefore, when the voltage of the AC power supply increases, it flows to the electromagnet coil connected through this thyristor 2. The current increases and the amplitude increases. In order to deal with this, it is conceivable to provide a constant voltage control circuit separately, but the cost will increase accordingly.

[0006]

[Problems to be solved by the device]

 The present invention has been made in view of the above problem, and an object of the present invention is to provide a constant amplitude control circuit for an electromagnetic vibrating device, which can use a conventional constant amplitude control circuit almost as it is and can also perform constant voltage control.

[0007]

[Means for solving problems]

 The purpose of the above is to supply the output of the amplitude detector, which detects the amplitude of the moving part of the electromagnetic vibrating device in which the electromagnet coil is connected to the AC power source via the thyristor, to one of the comparison input terminals of the comparator, The voltage corresponding to the set amplitude value is supplied to the other comparison input terminal of the comparator, and the output of the comparator is supplied to the thyristor phase control circuit via the PI control circuit to control the thyristor phase control circuit. In the constant amplitude control circuit, which supplies a gate pulse as an output to the gate terminal of the thyristor to automatically control the amplitude of the movable part of the electromagnetic vibration device to the set amplitude value, the comparator A switch is provided on the input side of the control power supply to connect one of the comparison input terminals to the amplitude detector side during constant amplitude control and to the thyristor phase control circuit during constant voltage control. Tiger A small signal thyristor or field effect transistor is connected to the secondary winding of the gate, and a gate pulse as an output of the thyristor phase control circuit is supplied to this gate terminal or control terminal to supply the small signal thyristor. This is achieved by a constant amplitude control circuit for an electromagnetic vibration device, characterized in that the changeover switch is changed over so as to rectify the current flowing through and to supply it to the one comparison input terminal.

[0008]

[Action]

 The gate terminal of the small signal thyristor, which is connected to the secondary winding of the control transformer for the power supply of the thyristor phase control circuit, receives a gate pulse according to the voltage fluctuation, and the gate terminal of this small signal thyristor. The voltage of the secondary winding of the control transformer also fluctuates at the same time, and the current flowing through this thyristor also fluctuates, but this is rectified and supplied to one input terminal of the comparator. Therefore, the phase of the gate pulse supplied to the high current control thyristor is adjusted according to the fluctuation of the alternating current voltage at this time. Therefore, the amplitude of the movable part of the electromagnetic vibration device can be made constant. Constant voltage control can also be performed by simply adding a small signal thyristor and switching the changeover switch provided on the input side of the comparator.Therefore, a separate constant voltage control circuit is required when performing conventional constant voltage control. The cost of the device can be greatly reduced as compared with the case where it is provided.

[0009]

【Example】

 Hereinafter, a constant amplitude control circuit for an electromagnetic vibration device according to an embodiment of the present invention will be described with reference to FIG. The parts corresponding to those in the drawing of the conventional example are designated by the same reference numerals, and detailed description thereof will be omitted.

That is, in FIG. 1, a small signal thyristor 29 is connected to the secondary winding of the control power supply of the thyristor phase control circuit, and a parallel circuit of a resistor 31 and a capacitor 32 is connected to the cathode side of the thyristor 29. Are connected. Further, this cathode is connected to a manual contact via a thickener 55. That is, by switching the changeover switch or the movable contact 13 to the manual contact side, a voltage obtained by rectifying the output current of the small signal thyristor 29 is applied.

FIG. 2 shows a main part in FIG. 1. The following is a description of this. The voltage corresponding to the set amplitude at one comparison input terminal of the comparator 15 is the amplitude in FIG. Although the volume is supplied via the setting volumes 34 and 21, they are collectively shown as one volume 103. The difference output of the comparator 15 is supplied to the PI control circuit 100, which collectively shows the P control circuit 16 and the I control circuit 17 in FIG. 1, and this output is supplied to the thyristor phase control circuit 19. In FIG. 1, the trigger generator circuit is illustrated as being included in the thyristor phase control circuit 19, but this has a built-in trigger generator 19a, but since it is particularly relevant to the present invention, it is taken out and shown as 19a, This output, that is, the trigger output, is supplied to the gate terminal 2a of the large current control thyristor 2 via the transformer T as in the conventional case. The electromagnet in the drive unit 3a of the electromagnetic vibration feeder F is connected to the AC power supply 104 via the thyristor 2 described above.

The trigger output of the trigger generator 19 a is supplied to the gate terminal 29 a of the small signal thyristor 29 via the resistor 111. Also, a parallel circuit of a resistor 31 and a capacitor 32 is connected to this cathode, which constitutes a rectifier circuit. The rectified output of the cathode is connected to the manual contact of the switching device 102 via the amplifier 55. is supplied to a. The movable contact 13 switches between the automatic contact 11 and the manual contact a as described above, and the movable contact 13 is connected to the other comparison input terminal of the comparator 15.

At the previous stage of the trigger generator 19a, the control circuit 300 including the comparator 15, the PI control circuit 100, and the thyristor phase control circuit 19 is connected as shown by the alternate long and short dash line. A transformer 105 is connected to the AC power supply 104 to supply a power supply for the power supply, and the anode side of the small signal thyristor 29 is connected to the secondary winding 105a. The voltage generated in the secondary winding 105a is used as the power source of the control circuit 300.

A power supply circuit used for setting the amplitude is connected to the resistor 103, and the same AC power supply as the above AC power supply 104 is also connected to the resistor 103, which is stepped down by a transformer and rectified. After that, a constant voltage diode is inserted to supply a constant voltage even if the voltage fluctuates. Therefore, the voltage set at one input terminal of the comparator 15 is not affected even if the voltage of the AC power supply fluctuates greatly.

The constant amplitude control circuit according to the embodiment of the present invention is constructed as described above. Next, its operation will be described. When performing the constant amplitude control, the movable contact 13 is connected to the illustrated automatic contact 11 in the changeover switch 102. Since the output of the amplitude detection pickup 4 attached to the trough 3 of the electromagnetic vibration feeder F is supplied to the contact 11 via the amplifier 101 as in the conventional case, this is the other input terminal of the comparator 15. Is supplied to. Therefore, the voltage corresponding to the amplitude at this time is given to the comparator 15, the difference between this and the set voltage is supplied to the proportional-plus-integrator circuit 100, and the output corresponding to this difference is supplied to the thyristor phase control circuit 19. Here, as is well known, a gate pulse (B in FIG. 3) having a phase (with respect to the power supply voltage of the AC power supply 104 (A in FIG. 3)) such that the output of the comparator 15 becomes 0 is generated. The signal is supplied to the trigger generator 19a. This gate output is supplied to the gate terminal 29a of the small signal thyristor 29 via the resistor 111. At this time, the voltage on the cathode side has a waveform as shown by D in FIG. 3 (when the capacitor 32 is removed), but a voltage as shown by a chain line is obtained by the rectifying circuit composed of the capacitor 32 and the resistor 31. This is amplified by the amplifier 55 and supplied to the manual contact a. However, the movable contact 13 is now connected to the automatic contact 11 side, and the output pulse generated from the trigger generator 19a is supplied to the gate terminal 2a of the large current control thyristor 2 via the secondary side of the transformer T. Thus, the electromagnet of the drive unit 3a of the electromagnetic vibration feeder F is controlled so that the amplitude is constant even if the voltage of the AC power supply 104 changes.

Next, a case where constant voltage control is performed will be described. This is the case when the vibration detection pickup 4 is not attached to the trough 3, for example, when the electromagnetic vibration feeder F is extremely high, and the detection output from this pickup 4 is placed on the ground. This is the case when the conductor wire for deriving the signal to the control circuit becomes very long, and high cost is required for its protection and noise prevention. In such a case, the switch 102 is switched to the manual contact a side. Therefore, the same amplitude set value is supplied as a voltage to one input terminal of the comparator 15, but the gate pulse output from the trigger generator 19a is supplied to the small signal thyristor 29 via the resistor 111. It is supplied to the gate terminal 29a. On the other hand, since the thyristor 29 is connected to the secondary winding 105a of the transformer 105, if the voltage of the AC power supply 104 increases now, the voltage of the secondary winding 105a naturally has the same ratio. Increase with. Therefore, the current flowing through the thyristor 29 increases, but the gate pulse applied to the gate terminal 29a rectifies the output voltage of the thyristor 29 with the resistor 31 and the capacitor 32, and the broken line D in FIG. Since the voltage shown in the table is supplied to the contact a, the phase of the trigger pulse is controlled so that the difference between this voltage and the set voltage is 0. It is connected to the secondary winding 105a of the transformer 105. The load of the small-signal thyristor 29 is a resistor 31 and the actual load is an L load, so it cannot be said that the simulation is performed in a strict sense, but as shown in C and D of FIG. Since an output voltage substantially corresponding to the change of the AC power supply 104, that is, a cathode voltage having a waveform simulating C in FIG. 3 is generated, the output of the comparator 15 is set so that this becomes the set amplitude. Therefore, after all, when the voltage of the AC power supply 104 rises, the phase of the gate pulse is adjusted so that the voltage applied to the electromagnetic coil of the drive unit 3a of the electromagnetic vibration feeder F becomes the original voltage. . Therefore, the amplitude of the trough 3 becomes almost constant.

FIG. 4 shows the relationship between the voltage of the AC power supply and the amplitude in order to show the effect of this embodiment. When the power supply changes from 180 V to 240 V at 50 Hz, As the data indicates by ◯, it hardly changes from the set values of 1.0 mm, 1.5 mm and 2.2 mm at 200 V, but according to the conventional controller (same as FIG. 5), As shown by the mark, when the set value is 1.0 mm, when it fluctuates between 180 V and 240 V, it fluctuates from a swing of about 0.70 mm to a swing of 1.7 mm. Also, if the set value is 1.5 mm, it will increase to about 2.8 mm at 240 V, and if the set value is set to 2.2 mm, it will already rise to 3.2 mm at 210 V, and it will move with the electromagnet. If the gap between the core and the core is 3 mm, the movable core and the electromagnet have already collided with each other. If the amplitude is further increased, the movable core or the electromagnet will be destroyed. However, in this embodiment, the amplitude is almost the same as the set value even if the voltage is all increased to 240 V as shown by the data value of Δ, and the electromagnet and the movable core do not collide.

As described above, in the present embodiment, even if the voltage of the AC power supply fluctuates in the manual operation, the voltage applied to the electromagnetic vibration feeder is made constant at the initial set value, and the amplitude is made constant. However, it is sufficient to connect a thyristor to the secondary winding 12 of the transformer for control power supply, which is originally necessary, and connect a resistor 31 and a capacitor 32 for rectifying this output. However, the above-described excellent effect can be obtained without increasing the cost by leaving the conventional constant amplitude control circuit almost unchanged.

Although the embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made based on the technical idea of the present invention.

For example, although the electromagnetic vibration feeder has been described as the electromagnetic vibration device in the above embodiments, the present invention can be applied to a vibration parts feeder, a vibration tester, etc., of course.

Further, in the above embodiments, the small signal thyristor 29 is used. Instead of this, an FET, that is, a field effect transistor is used, and a gate pulse which is the output of the thyristor phase control is applied to this control terminal. Even if it is applied, the same operation can be performed and the effect can be obtained.

[0022]

[Effect of device]

 As described above, according to the constant amplitude control circuit for an electromagnetic vibration device of the present invention, constant voltage control can be performed with almost no increase in cost.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a constant amplitude control circuit for an electromagnetic vibration feeder according to an embodiment of the present invention.

FIG. 2 is a circuit diagram of a main part in FIG.

FIG. 3 is a waveform chart of each part in FIG.

FIG. 4 is a graph comparing this example with a conventional example.

FIG. 5 is a circuit diagram of a conventional constant amplitude control circuit for an electromagnetic vibration feeder.

[Explanation of symbols]

 15 comparator 29 small signal thyristor 31 resistor 32 capacitor 102 changeover switch

Claims (1)

[Scope of utility model registration request] 1. An output of a amplitude detector for detecting an amplitude of a movable part of an electromagnetic vibration device in which an electromagnet coil is connected to an AC power source via a thyristor is supplied to one comparison input terminal of a comparator, A voltage corresponding to the set swing value is supplied to the other comparison input terminal of the comparator, and the output of the comparator is supplied to the thyristor phase control circuit via the PI control circuit to control the thyristor phase control circuit. In a constant amplitude control circuit for supplying a gate pulse as an output to the gate terminal of the thyristor to automatically control the amplitude of the movable part of the electromagnetic vibration device to the set amplitude value, A change-over switch is provided on the input side, and one of the comparison input terminals is connected to the amplitude detector side during constant amplitude control, and a constant voltage control of the control power transformer connected to the thyristor phase control circuit. Two A small signal thyristor or field effect transistor is connected to the next winding, and a gate pulse as an output of the thyristor phase control circuit is supplied to this gate terminal or control terminal to rectify the current flowing through the small signal thyristor. Then, the constant amplitude control circuit for an electromagnetic vibrating device is characterized in that the changeover switch is switched so as to be supplied to the one comparison input terminal.