JPS6051189B2 - magnetic bubble drive circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic bubble device that drives magnetic bubbles using a rotating magnetic field.

BACKGROUND ART Conventionally, as a rotating magnetic field generating circuit for driving a magnetic bubble, a circuit has been proposed that utilizes a resonant circuit consisting of a magnetic field generating coil and a capacitor connected in series with the magnetic field generating coil.

According to this conventional circuit, a rotating magnetic field having a constant magnitude and changing at a constant angular velocity can be obtained. However, such a conventional method requires a capacitor with a large capacity to form a resonant circuit. The cost increases accordingly. Another problem is that the capacitance of the capacitor must be set constant in order to keep the resonance frequency constant. Further, there is a problem that control of starting and stopping the rotating magnetic field becomes complicated. The present invention was made in order to eliminate the problems of the prior art as described above, and is an extremely simple method of generating a magnetic field suitable for driving a magnetic bubble without using a resonant capacitor. The object is a magnetic bubble drive device having a simple rotating magnetic field generation circuit.

Therefore, in the present invention, a circuit is used in the rotating magnetic field generating coil to flow a current that changes linearly, for example, triangularly over time.

FIG. 1 shows an embodiment according to the invention. Coil 3X, 3Y
are circuits that generate magnetic fields in the X-axis direction and Y-axis direction, respectively. In the figure, these coils appear to be placed in the same direction, but in reality, both coils are placed so that the magnetic fields they produce are orthogonal. 1X and 2X are switches that control the current flowing through this coil 3X, and similarly 1
Y, 2Y are switches that control the current flowing through this coil 3Y.

Voltage sources 4X, 5Y, 4Y, 5Y connect these coils 3X,
This is for supplying current to flow through 3Y. Figure 2a
indicates the on/off status of these switches 1X, 2X, 1Y, and 2Y, and B and c indicate the coil 3, respectively.
It is a diagram showing currents 1x and iy flowing into X and 3Y, and d
is a time axis indicating time.

FIG. 3 is a diagram showing changes in the vector of the magnetic field generated by the circuit of FIG. 1.

The operation of the circuit shown in FIG. 1 will be explained below based on FIGS. 2 and 3. At time 1, only switch 1X is turned on.
As a result, current flows from the voltage source 4X into the coil 3X through the switch 1X. At this time, if the resistance of the switch 1X is sufficiently small, the current 1x increases linearly with a slope determined by the inductance of the coil 3X and the output voltage of the voltage source 4X.ノ At the time, switch 1
X is turned off and switch 2X is turned on. As a result, Ix becomes maximum at time t1. Further, as a result of this switch control, terminal A of the coil 3X and the voltage source 5X are connected. This voltage source 5X outputs an angular voltage with the same absolute seven values as the voltage source 4X. Since the current flowing through the coil 3X at time t1 does not change rapidly, the current changes directly from the current value at that time until the next time ζ. The slope of the change at this time has the same absolute value as the slope of the change between time t1 and time T3O, and the current 1x takes its minimum value. At time 1, switch 2X is turned off and switch 1X is turned on.

As a result, the current Ix increases again and reaches its maximum at time T5. In the end, one cycle of operation was performed from time t1 to time T5. Thereafter, the operation is repeated for the required number of cycles in exactly the same manner. On the other hand, voltage sources 4Y and 5Y for controlling the current flowing through coil 3Y output voltages equal to voltage sources 4X and 5X, respectively, and coils 3X and 3Y are selected to have the same inductance.

The switches 1Y and 2Y are controlled so that the current 1 flowing through the coil 3Y lags the current 1x by 1/4 period, but has exactly the same waveform. As a result of the above operations, the vector diagram of the magnetic field generated by the coils 3X and 3Y takes the form shown in Figure 3.

In other words, at time t, the vector is at the origin 0,
It changes as if moving towards point A on the x-axis until the time reaches the end.
It is at point A at time t1.

From time t1 to time T2, the vector moves from A to B along the side oil. At time T2-T3, the vector is B along side BC.
From there, go to C. At time T4, the vector moves from C to D along side CD. From time ζ to T5, the vector moves from D to A along side DA. The following is repeated as many times as necessary. After that, Vector is a pig! When returning to point A again at It9, switches 1Y and 2Y are kept off and only switch 2X is turned on.

At time TlO, all switches are turned off. This time T. -TlO, the current 1x decreases to zero. The vector goes from A to 0. All operations are now complete. Switches 1X, 2X, 1Y, 2Y in this embodiment
．． can be constructed using a transistor or the like.

In the following, an example using a transistor will be described in the case of triangular wave drive. All of the example circuits shown below are
5 is configured to return the electromagnetic energy stored in the coil to the power source.

Therefore, the power consumption of the circuit can be extremely reduced. FIG. 4 shows an example using bidirectional transistors 1A and 1B.

Transistors 1A and 2A are PNP and NP, respectively.
It is an N-type bidirectional transistor.

The bases and one other electrode of transistors 1A and 2A are connected to the secondary sides of pulse transformers 6 and 7, respectively. Rectangular pulses are alternately applied to the primary sides of the pulse transformers 6 and 7, and as a result, the voltage of the electrode 10 of the transistor 1A with respect to the base 20 and the voltage of the base 50 of the transistor 2A with respect to the electrode 60 are respectively It is changed as shown in Figure El3e2.

Further, at this time, the current flowing into the A terminal of the coil 3 becomes as shown in FIG. 8.

When period T1 begins, the transistor 2A is turned off), while the transistor 1A is connected to the terminal A of the coil 3 until then.
The current flowing out from the current flows in.

That is, during this period, the transistor 1A acts as a transistor in which the electrode 30 acts as an emitter and the electrode 10 acts as a collector. In other words, with approximately the positive voltage of voltage source 4 and the ground voltage being applied to terminals A and B of the coil, coil terminal A → transistor 1A → positive voltage output terminal of voltage source 4 → 0 voltage output of voltage source 4. Current flows along the path from the terminal to the B terminal of the coil 3.

Since a positive voltage is applied to the A terminal of the coil 3, the current flowing out from the coil 3 gradually decreases. When this current becomes zero, the next T2 period begins.

First, during the period indicated by T2, the PN junction between the electrode 10 and the base 20 is in a conductive state, so the transistor 1
A is a transistor in which the electrodes 10 and 30 act as an emitter and a collector, respectively. At this time, a current 1 flows into the coil 3 from the power source 4 through the transistor 1A as shown in FIG. Furthermore, since the substantial resistance of the transistor 1A is small at this time, the current increases almost linearly with time. During the period indicated by period T3, the transistor 1A is in an off state.

On the other hand, the transistor 2A operates as a transistor with the electrode 40 as an emitter and the electrode 60 as a collector. That is, at the end of the period 12, the current flowing through the coil 3 does not change rapidly even at the start of the period T3, so the transistor 2A operates as a transistor with the electrode 40 as the emitter and the electrode 60 as the collector.

That is, at the end of the period T2, the current flowing through the coil 3 does not change rapidly even at the start of the period T3, and therefore starts flowing in the direction from the electrodes 60 to 40 of the transistor 2A. That is, with the negative voltage and ground voltage of voltage source 5 applied to coil A and B terminals, respectively, coil terminal B → ground voltage terminal of voltage source 5 → negative voltage terminal of voltage source 5 → transistor 2A → coil Current flows through the path called terminal A. Thereafter, this current gradually decreases to zero due to the negative voltage source 5. After that, period T4 begins, and since the junction between the base 50 and the electrode 60 is biased in the forward direction, the transistor 2A operates with the electrodes 60 and 40 as emitters and collectors, and current flows out from the terminal A of the coil. become. Repeat the same cycle.

In this way, in the embodiment shown in FIG. 4, the current path connecting the voltage source 4 and the terminal A of the coil 3 is a common path, and the bidirectional transistor 1A is installed in this common path. be.

As a result, this common path is used both when the current flows from the voltage source 4 to the coil 3. The above also applies to the current path with bidirectional transistor 2A. As described above, since the circuit of FIG. 4 uses bidirectional transistors, the circuit is extremely simple. FIG. 5 shows a circuit according to the present invention using a unidirectional transistor as a switching element. 1B and 2C are PNP transistors, and 1C and 2B are NPN transistors.

6A, 6B, 7A, and 7B are pulse transformers.

Transistors 1B and 1C have their base-emitter junctions conductive during periods τ1 and T2, and during periods T3 and T4.
Each pulse that is non-conductive for a period of time is connected to a pulse transformer 6A.
, 6B. The transistors 2B and 2C have their base-emitter junctions connected for periods Tl and T2.
Pulses are applied by the pulse transformers 7A and 7B to make the terminals non-conductive during the period T3 and conductive during the periods T3 and T4, respectively. In this circuit, between periods T1 and T2, transistors 1B and 1C are conductive, and during period T1, current flows from the A terminal of coil 3 to power supply 4 via transistor 1C, and during period T2, current flows from power supply 4 to the coil through transistor 1B. Current flows into 3.

That is, during period T1, power P1 is fed back to the power source through transistor 1C. In period T2, transistor 1
Electric power P2 is supplied to the coil 3 through B. Period T3
, T4 as well. During period T3, current flows from the power supply 5 to the coil 3 via the transistor 2C,
During period T4, current flows from the coil 3 to the power supply 5 via the transistor 2B. As a result, transistor 2C
Power P3 is fed back through the transistor 2B, and P4 is supplied to the coil 3 through the transistor 2B. Therefore, the power loss in the drive circuit is the product of the voltage drop across the switching element and the flowing current.In general, the voltage drop across the switching element is small, resulting in a drive circuit with low loss. Furthermore, since the switching element also has little power loss, inexpensive elements can be used. Further, unlike the circuit shown in FIG. 4, since a unidirectional current switch is used, high-speed operation is possible. FIG. 6 shows an embodiment in which a current path for feeding back power from the coil 3 to the power sources 4 and 5 is constructed by a path consisting of diodes 1D and 2D.

The transistor 1B is in the on state during the periods Tl and T2, respectively, and is in the T state, just like the transistor 1B in FIG.
3. The voltage is applied by the voltage pulse transformer 6 which is in an off state during T4. Transistor 2B is controlled in exactly the same way as transistor 2B of FIG. As a result, during period T1, current flows from the coil 3 to the power source 4 via the diode 1D, and during period T2, current flows from the power source 4 to the coil 3 via the transistor 1B. During period T3, current flows from power supply 5 to coil 3 via diode 2D. During period T4, transistor 2B
Current flows from the coil 3 to the power source 5 via. The circuit shown in Figure 6 is compared to the circuit shown in Figure 5.
is not necessary and is that simple.

FIG. 7 shows an embodiment constructed using only a single positive voltage source 4. In FIG.

A voltage is applied between the base and emitters of the transistors 1B, 1C, and 1E by pulse transformers 6A, 6B, and 6C, respectively, so that the junction thereof is turned off during periods T1 and T2.

The transformer O transistors 2B, 2E, and 2F are connected to pulse transformers 7C, 7A, and 7B, respectively, which are off during the junction periods Tl and T2 and off during T3 and T4 between their base and emitters. is applied by In period T1, A terminal of coil 3→transistor 1C→
Current flows from the coil to the current source through the current path: voltage source 4 → ground → diode 1F → B terminal of coil 3 → A terminal of coil 3, and during period T2, voltage source 4 → transistor 1B → A terminal of coil 3 → B terminal of coil 3 →
Current flows in the closed circuit of transistor 1E→earth→power supply 4 in the direction shown here.

During period T3, current flows through a closed circuit of B terminal of coil 3→transistor 2F→voltage source 4→earth→diode 2D→A terminal of coil 3→B terminal of coil 3, and in the direction shown here.

During period T4, voltage source 4 - transistor 2E -> B terminal of coil 3 -> A terminal of coil 3 -> transistor 2B
Current flows through a closed circuit of → ground → voltage source 4 and in the direction shown here. This circuit is simple because it uses only a single power supply.

Although the above example shows an example in which transistors are controlled on and off using a pulse transformer, the present invention is not limited to this, and it is also possible to use other circuits, such as logic circuits made of transistors. It is. As described above, a magnetic bubble drive having a circuit with a simple configuration generates a magnetic field whose magnitude continuously changes linearly with time, for example, a magnetic field whose magnitude changes triangularly with time. A circuit is obtained.

Although the vector shape of the rotating magnetic field according to the present application changes from a perfect circle to a polygonal shape, the magnetic bubble was normally driven even by such a rotating magnetic field.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an embodiment of the circuit of the present invention, FIG. 2 is a diagram explaining the operation of the circuit of FIG. 1, and FIG.
FIG. 4 shows an example of the circuit according to the present invention using bidirectional transistors, and FIG. 5 shows the locus of the rotating magnetic field vector generated by the circuit of FIG. FIG. 6 is an example of a circuit using diodes in place of the transistors 1C and 2C in FIG. 5.

FIG. 7 is an example of a circuit according to the present invention in which one constant voltage source is used to flow an alternating current through a coil. FIG. 8 is a diagram showing the operating voltage and current of the circuit of FIG. 4. 1X. 2X, 1
Y, 2Y...Switch, 3X, 3Y...Coil, 4X, 4Y, 5X, 5Y...Voltage source, 1
...Switching element, 1A...PNP type bidirectional transistor, 1B...NPN type bidirectional transistor, 1B, 2C, 2E,...PNP type unidirectional transistor, 2B , 1C, 2F... NPN type unidirectional transistor, 3... Coil, 4...
Positive voltage source, 5...Negative voltage source, 6, 6A, 6B,
6C, 7, 7A, 7B, 7C...Pulse transformer.

Claims (1)

[Claims] 1. A plurality of magnetic field generating coils, each of the coils having a predetermined waveform and phase, and a period equal to the above period in response to a predetermined drive signal that is repeatedly input at a predetermined period. and a plurality of coil drive circuits for causing the coil to generate a rotating magnetic field, each of the coil drive circuits supplying the coil with a predetermined maximum voltage within each period It has a current path for supplying a current that changes linearly and continuously over time between a value and a minimum value, and the plurality of coils generate a rotating magnetic field in which the locus of the magnetic field vector is polygonal. Magnetic bubble drive circuit. 2 The plurality of coils are two coils, and each current path of the coil drive circuit for driving each coil is a current path for passing a current that continuously changes in a triangular shape with time in the coil. The currents flowing through the two coils have a phase shift of 1/4 period from each other, and the magnetic bubble of the first term generates a rotating magnetic field in which the locus of the magnetic field vector is rectangular by the two coils. drive circuit. 3. Each current path includes (a) a voltage source for outputting a DC voltage of a plurality of predetermined levels; and (b) conduction for a predetermined first period in response to the drive signal, and a first voltage source of the coil. A first current path for flowing a first current that linearly increases over time from 0 to a first value into the coil via a terminal, the first current path connecting the first and second terminals of the coil. (c) a first current path connected to one of the pair of output terminals of the voltage source with a higher output voltage and the other with a lower output voltage; and (c) the first current path changes from a conductive state to a non-conductive state. After that, the current of the second value is flowing in the coil in the direction from the first terminal to the second terminal, and the coil becomes conductive for a predetermined second period. a second current path for flowing a second current that linearly decreases over time from the second value to 0 from the coil to the voltage source via a second terminal; (d) a second current path connecting the first and second terminals of the voltage source to the lower and higher output voltage of the pair of output terminals of the voltage source; and (d) a second current path responsive to the drive signal. becomes conductive during a predetermined third period, and via the second terminal of the coil,
a third current path for passing a third current that linearly increases with time from 0 to a third value through the coil, the first and second terminals of the coil being respectively connected to the voltage source; a third current path connected to one of the pair of output terminals having a lower output voltage and the other having a higher output voltage, and (e) after the third current path changes from a conductive state to a non-conductive state; , becomes conductive when a current of a fourth value is flowing in the coil in the direction from the second terminal toward the first terminal,
a fourth current for flowing a current that linearly changes over time from the fourth value to 0 from the coil to the voltage source via the first terminal of the coil for a predetermined fourth period; and a fourth current path connecting the first and second terminals of the coil to the one having a higher output voltage and the one having a lower output voltage, respectively, of a pair of output terminals of the voltage source. A magnetic bubble drive circuit featuring: 4. In the circuit according to claim 3, the first and fourth current paths are also constituted by a first common current path, and the first common current path is driven by the drive signal. It has a bidirectional first switching element whose conduction is controlled, the second and third current paths are also constituted by a second common current path, and the second common current path is It has a bidirectional second switching element whose conduction is controlled by the drive signal, and the second switching element supplies the first current to the coil from the power supply. At least the second current is applied from the coil to the second terminal during the predetermined second period after the state changes from a conductive state to a non-conductive state with respect to the direction in which the current flows through the first terminal. conduction in the direction in which the current flows into the power source through the power source, and during the third period after the second current finishes flowing, the third current flows from the power source to the coil through the second terminal. The first switching element is controlled to be conductive in the direction of flow, and the first switching element is controlled to conduct in the direction of flow during the first period in which the first current flows from the power source to the coil via the first terminal. conduction occurs, and further, during the fourth period after the third current finishes flowing, conduction occurs in the direction in which the fourth current flows from the coil to the power source via the first terminal. A magnetic bubble drive circuit characterized in that it is controlled. 5. In the circuit according to claim 3, the voltage source has high level and low level voltage output terminals, and the first current path connects the high level output terminal of the voltage source and the coil. a first switching means provided between the first terminals and conducting in response to a drive signal so that a current flows in a direction from the high level output terminal toward the first terminal for the first period; provided between a low level output terminal of the voltage source and a second terminal of the coil, in response to a drive signal;
a second main switching stage that conducts during the first period so that a current flows from the second terminal to the low level output terminal; is provided between a level output terminal and a second terminal of the coil, and in a state where the first and second switching elements are non-conductive, the high level output is output from the second terminal during the second period. a first current control means conductive so that the current flows only in a direction toward the terminal; and a first current control means provided between the low level output terminal of the voltage source and the first terminal of the coil;
and a second current control means that conducts current only in the direction from the low level output terminal toward the first terminal during the period of . provided between a high level output terminal and a second terminal of the coil, such that current flows in a direction from the high level output terminal toward the second terminal during the third period in response to a drive signal. third switching means conductive between the low level output terminal of the voltage source and the first terminal of the coil; and fourth switching means conductive so that current flows in the direction toward the level terminal. The fourth current path is provided between the high level output terminal of the voltage source and the first terminal of the coil, and the fourth current path is arranged between the high level output terminal of the voltage source and the first terminal of the coil. third current control means conductive so that a current flows in a direction from the first terminal to the high level output terminal of the voltage source; and a third current control means provided between the low level output terminal of the voltage source and the second terminal of the coil. and fourth current control means conductive so that current flows only in the direction from the low level output terminal toward the second terminal during the fourth period. 6. In the circuit according to claim 3, the voltage source has a first reference voltage, a second voltage higher than the first reference voltage by a predetermined amount, and a second voltage lower than the reference voltage by a predetermined amount. the first current path is provided between the second voltage output terminal of the voltage source and the first terminal of the coil, and the first current path is provided between the second voltage output terminal of the voltage source and the first terminal of the coil; a first switching means that conducts so that a current flows in a direction from the second voltage output terminal toward the first terminal during a first period; the second current path is provided between the third voltage output terminal of the voltage source and the first terminal of the coil, and the second current path connects the terminals of the coil. 3. A first terminal that allows current to flow only in the direction from the three voltage output terminals toward the first terminal.
and a conduction path, the third current path is provided between the third voltage output terminal of the voltage source and the first terminal of the coil, and the third current path is provided in response to a drive signal. The fourth current path includes a second switching means that conducts so that a current flows in a direction from the first terminal to the third voltage output terminal during the third period, and the conductive path. , provided between the second voltage output terminal of the voltage source and the first terminal of the coil, and during the fourth period, from the first terminal to the second
A magnetic bubble drive circuit comprising a second current control element that allows current to flow only in a direction toward a voltage output terminal, and the conductive path.