GB2156608A - Apparatus for generating alternating magnetic flux - Google Patents

Abstract

Thyristors SCR1, SCR2 conduct alternately so that capacitors C1, C2 are alternately discharged through a coil L, thereby alternating the current flow direction in the coil and producing an alternating magnetic flux. The capacitors C1, C2 are charged by respective D.C. supplier which may include a voltage multiplier circuit (D1, D2, C5, C6, Fig. 5). <IMAGE>

Description

SPECIFICATION Apparatus for generating alternating magnetic flux The present invention relates to an apparatus for generating an alternating magnetic flux using a single coil system.

In the activation of an affected site or cell in the body using a magnetic flux pulse generator, it is preferred to use an apparatus which generates an alternating pulsed line of magnetic induction having a waveform which is similar to that of a nervous diphasic action potential wherein positive- and negative- potential pulses appear alternately.

Such an alternating pulsed line of magnetic force may be generated with a single coil system by using transistor devices. The use of transistor devices is, however, unfavourable with a high current.

According to the present invention there is provided apparatus for generating an alternating magnetic flux with a single coil system, said apparatus comprising: (a) a plurality of dc power sources; (b) a plurality of thyristors; (c) a plurality of charge and discharge circuits having a time constant; and (d) a coil member; wherein the dc power sources are each connected to charge different charge and discharge circuits, and wherein each charge and discharge circuit is connected to the coil member through a different thyristor so that an alternating pulse current is applied to the coil member.

The invention also extends to an apparatus for generating a pulsed magnetic flux using a single coil, wherein currents from two insulated dc power sources are supplied, to a set of charge and discharge circuits having a time constant, and alternately the charges of capacitances in said circuits are supplied to a magnetic flux generating coil through a set of alternately operable thyristor circuits to supply an alternating current to the coil, whereby an alternating pulsed line of magnetic induction is generated with the single coil system.

Apparatus of the present invention is arranged to generate a strong alternating magnetic flux by supplying an alternating high current to a single coil system by way of thyristors in place of transistor devices.

Embodiments of the present invention will hereinafter be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a basic circuit diagram of apparatus for generating magnetic force of the invention, Figure 2 shows the waveform of the gate signal of a thyristor, Figure 3 shows the current waveform at a coil for generating magnetic flux pulses, Figure 4 shows a further embodiment of apparatus of the invention, and Figure 5 shows a circuit diagram of a voltage doubler which produces a dc output voltage equal to twice the peak voltage of an ac power source.

In the drawings, A indicates a rectifier; B represents a power source; C is a capacitance; D is a diode; L is a coil for generating magnetic flux; P is a resistance; T is a transformer; AC is an ac power source; and SCR is a thyristor.

In the circuit shown in Fig. 1, a dc power source B, charges a capacitance C, through a resistance R1. The charge on the capacitance C1 is then supplied to a coil L from terminal m, as well as to a thyristor SCR, from terminal n of the coil. This discharge current of the capacitance C, generates a magnetic field around the coil L having lines of induction N.

Similarly, a dc power source B2 charges a second capacitance C2 by way of a resistance R2. When a second thyristor SCR2 is conductive, the capacitance C2 discharges through the coil L by way of the terminal n, the terminal m, and the thyristor SCR2, such that a current with the opposite polarity flows through the coil L to generate lines of induction S of opposite polarity to the lines N.

The thyristors SCR, and SCR2 are arranged to conduct alternately by way of gate signals x and y as shown in Fig. 2 which are supplied to the respective thyristor gates x and y. Thus, pulsed discharge currents are generated whereby an alternating pulsed magnetic flux is generated at the coil L as indicated in Fig.

3.

The circuit shown in Fig. 4 illustrates an embodiment for providing a two dc power sources. An ac current is supplied from lamp wire AC to the primary coil P of a transformer T, and the current generated at the secondary coil 0 is then fed to a rectifier A, through a resistance R to effect full-wave rectification.

The rectified current is smoothed by way of a capacitance C3.

The smoothed current is arranged to charge the first capacitance C, by way of the series resistance R1, and the first capacitance C, is discharged through the coil L and by way of the first thyristor SCR1 as described above to generate the line of magnetic force N at coil L.

AC current from the ac power source AC is also supplied directly to a second rectifier A2 which is arranged to effect full-wave rectification, the rectified current being smoothed by way of a capacitance C4. This smoothed current is arranged to charge the second capacitance C2 through the series resistance R2. As is described above, the second capacitance C2 is discharged through the coil L and by way of the second thyristor SCR2 whereby the line of magnetic force S of opposite polarity is generated at the coil L.

By supplying the spaced gate signals x and y shown in Fig. 2 to the thyristors SCR, and SCR2, an alternating current is flowed through the coil L which generates an alternating magnetic flux as described above.

Fig. 5 illustrates a circuit diagram of a voltage doubler. The ratio of the secondary coil 0 of the transformer T to its primary coil P is 2, and the output of secondary coil Q is rectified to obtain a dc output voltage which is equal to twice the peak voltage of the primary coil P.

Alternatively, ac power source AC is connected directly to diodes D, and D2 to effect voltage-doubling rectification to obtain a dc output voltage equal to twice the peak voltage of the ac power source.

Claims (8)

1. Apparatus for generating an alternating magnetic flux with a single coil system, said apparatus comprising: (a) a plurality of dc power sources; (b) a plurality of thyristors; (c) a plurality of charge and discharge circuits having a time constant; and (d) a coil member; wherein the dc power sources are each connected to charge different charge and discharge circuits, and wherein each charge and discharge circuit is connected to the coil member through a different thyristor so that an alternating pulse current is applied to the coil member.

2. Apparatus as claimed in Claim 1, wherein each said charge and discharge circuit is a CR time constant circuit.

3. Apparatus as claimed in Claim 1 or 2, wherein each said dc power source is a rectifier circuit.

4. Apparatus as claimed in Claim 3, wherein said rectifier circuit is a full-wave rectifier circuit.

5. Apparatus as claimed in Claim 3, wherein said recitifer circuit is a voltage-doubler circuit.

6. Apparatus as claimed in any preceding claim, wherein said generated magnetic flux has a waveform of the diphasic action potential.

7. Apparatus for generating an alternating magnetic flux comprising a single magnetic flux generatng coil and two alternately operable supply circuits each arranged to flow current through said coil to generate magnetic flux, the current supplied by said two circuits flowing in opposite directions through said coil, each of said supply circuits being connectible to said coil by way of a respective alternately triggerable thyristor circuit.

8. Apparauts for generating an alternating magnetic flux substantially as hereinbefore described with reference to the accompanying drawings.