JPS6048831B2 - Pulse current drive device for bubbles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pulse current drive device in a magnetic bubble device.

The pulse current drive device is used to generate, eliminate, and divide bubbles in the bubble chip, and plays an important role in assembling the bubble chip as a device. Conventionally, as shown in FIG. 1, a conductor 3 of a current loop intersects with a permalloy pattern 2 for bubble propagation on a bubble chip 1.
A first voltage source 4 is connected to the first terminal a of the , a current value setting resistor 6 is connected to the second terminal of the transistor 7, and a transistor 7 whose emitter is connected to the second power source 5 is connected in series to control the base of the transistor 7. A circuit configuration was adopted in which a pulse generator 8 was added.

In this case, in order to supply a pulse current to the conductor 3, it is only necessary to apply a control voltage from the control pulse generator 8 to the base of the transistor 7 to turn on the transistor 7 for a specified pulse width. However, the control pulse generator 8, which determines the pulse width of the control voltage to the transistor, becomes abnormal during power-on and power-off waves, and the transistor 7
If a short-circuit occurs in the conductor 3, the drive duty ratio of the pulse current flowing through the conductor 3 will exceed the specified value, or the pulse width will exceed the specified value, causing the conductor 3 to melt in the current bubble chip 1. happens. In order to prevent this, conventional measures had to be introduced in the control pulse generator 8 to prevent the drive duty ratio from exceeding a specified value or the pulse width from exceeding a specified value. For this reason, the conventional pulsed current drive device for bubbles requires an expensive measure to prevent disconnection in the control pulse generator 8, and without this, the bubble chip 1 has a defect that reduces reliability. Furthermore, such measures could not prevent the conductor 3 from being blown out due to a short circuit in the transistor 7. The present invention is intended to correct the above-mentioned defects, and as shown in FIG.
A capacitor 9 is connected in series to the conductor 3, a current regeneration resistor 10 is connected in parallel to the series circuit of the conductor 3 and the capacitor 9, and a first voltage source 4 is connected to the first terminal a' of the resistor 10. , the collector of a transistor 7' is connected to the second terminal b', a current value setting resistor 6' is connected between the emitter of this transistor 7' and the second voltage source 5, and the transistor 7' The reason is that the control pulse generator 8 is connected to the base of the control pulse generator 8.

In this case, since the transistor 7' works as a pulse current source, the amplitude of the pulse current is not affected by the voltage V of the first voltage source 4 or the resistance value RO of the current regeneration resistor 10, and the amplitude of the pulse current is The control voltage to be output and the voltage V of the second voltage source 5
.

and the resistance value of the resistance value 6'. With such a circuit configuration, a pulse current with a short pulse width faithfully flows to the conductor 3 because the impedance of the capacitor 9 is sufficiently smaller than RO with respect to high frequency components.

However, as long as the capacitor 9 is used, sag and undershoot of the pulse current cannot be avoided. If the product (time constant) of 10 and the resistance value RO is chosen to be sufficiently larger than the pulse width Ts, it can be kept considerably smaller. Ru. On the other hand, when a control voltage with a long pulse width is applied to the transistor 7', a pulsed current initially flows to the conductor 3, but after a while, the impedance of the capacitor 9 becomes higher than RO, so that the current regeneration resistor 10 trying to flow in the direction

However, since the CRO is large, the amplitude of the pulse current is reduced slowly, and the risk of wire breakage cannot be simply avoided.
To effectively prevent wire breakage, the permissible pulse width Ts is
If a pulse current with a longer pulse width is about to flow,
V or C may be selected so that the transistor 7' is saturated (the collector potential is below the base potential). That is, the difference (V1-Vb) between V and the base potential Vb of the transistor 7' when conducting, and the amplitude I of the pulse current. If the ratio between the pulse width Ts and the capacitance C of the capacitor 9 is made smaller than the ratio between the pulse width Ts and the capacitance C of the capacitor 9, the voltage of (V,
A voltage drop equal to -Vd) occurs, and the saturation of transistor 7' inhibits the supply of pulsed current to conductor 3. This means that with a wide control voltage, the pulse width T
This means that a pulse current of s can be generated, which is useful in reducing the cost of the control pulse generator 8.

Therefore, let the driving period be Tp and I. Drive duty ratio (Ts/Tp) that does not cause disconnection with a pulse current of
If the upper limit of is α, then the product of (V, 1CVb) and 1 is αI
It is said that it is fine as long as it is smaller than O.

In other words, it can be seen that by reducing (V, -Vb) and C, wire breakage can be avoided and the cost of the control pulse generator 8 can be reduced. As described above, according to the present invention, the problem of conductor breakage, which is a defect of the conventional bubble pulse current drive device, can be easily solved.
It is sufficient that the resistance value RO of the resistor 10 is determined to be large enough to make CRO sufficiently larger than the specified pulse width Ts once C is determined.

Moreover, the effect becomes even greater when the capacitor 9 and the resistor 10 are built into the packaging case 11 of the bubble module.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing a conventional bubble pulse current driving device, and FIG. 2 is a circuit diagram showing an embodiment of the present invention. 1... Bubble chip, 2... Bubble propagation pattern, 3... Current loop conductor, 4... First voltage source, 5...・Second
Voltage source, 6, 6'... Current value setting resistor, 7
,7'......Transistor,8...
・Control pulse generator, 9 ... Capacitor, 1
0...DC regeneration resistor, 11...Bubble module packaging case.

Claims (1)

[Claims] 1. A conductor of a current loop on a bubble chip, a capacitor connected in series with the conductor, a DC regeneration resistor connected in parallel to the series circuit of the conductor and the capacitor, and a first voltage source connected to the first terminal of the regeneration resistor; a transistor whose collector is connected to the second terminal of the DC regeneration resistor; and a transistor connected between the emitter of the transistor and the second voltage source. A bubble pulse current drive device comprising a current value setting resistor and a control pulse generator connected to the base of the transistor. 2. The bubble pulse current drive device according to claim 1, wherein the capacitance of the capacitor is selected to be small so that the transistor is saturated with respect to a pulse current having a pulse width exceeding the upper limit of the drive duty ratio.