JPH0341707A - Pulse transformer - Google Patents

Abstract

PURPOSE:To decrease leaking inductance and to output small, high-frequency pulses by constituting the windings of a transformer with insulated stranded wires wherein two insulated electric wires are twisted, splitting one insulated stranded wire into a plurality of wires equally, connecting the wires in parallel, and forming the primary winding. CONSTITUTION:Stranded wires 30 wherein an electric wire 31 covered with a thin insulating film and an electric wire 32 covered with a thick insulating film are twisted is wound around an iron ocre 20. The electric wire 31 is cut at a part of 1/2 of the total number of turns. The cut electric wires 31 are connected in parallel. The starting side of the winding of the wire is made to be a (u) terminal at the low voltage side, and the finishing side of the winding is made to be a (v) terminal. The terminals are connected a to a pulse power source. A (u) terminal at the starting side of the winding of the electric wire 32 and a (v) terminal at the finishing side of the windings are connected to a capacitor at the secondary side. Since the currents having the same magnitude flow through the electric wire 32 and the electric wire 31 of the stranded wires 30, the magnetic fluxes are completely offset. As a result, the leaking magnetic fluxes are decreased. Thus, the leaking inductance becomes very small.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to pulse transformers.

(Prior art) Conventionally, in order to obtain a large pulse-like current, a method has been used to open and close the circuit of a capacitor charged to a high voltage. etc. have been used. However, these thyratrons and gas gaps have short lifespans because their electrodes wear out due to arcing during discharge, so semiconductor devices are used instead, but these semiconductor devices have a higher withstand voltage than thyratrons and gas gaps. Since the value is low, it is necessary to step up the voltage with a high voltage pulse transformer.

FIG. 3 is a diagram showing an example of a pulse switching circuit using a semiconductor element. After the capacitor 1 is charged by the DC power supply 4 with the semiconductor switch lO in the off state, the semiconductor switch lO is turned on and the charge on the capacitor 1 is is discharged, and the capacitor 2 is charged by the pulse current flowing to the secondary side of the pulse transformer 3. And this charge is
For example, it is used to excite laser gas in gas laser equipment or to imitate pulsed magnetic fields.

By the way, the pulse output in this way requires a high frequency of the pulse that charges the capacitor 2, and in FIG. Leakage inductance of the pulse transformer 3 seen from the secondary side C1: Cabatacitance of the capacitor 1 converted to the secondary side of the pulse transformer 3 C2: Capacitance of the capacitor 2 Normally, Cl=C2 is set, so .

Therefore, the frequency f of the output pulse. In order to increase the output power, it is necessary to reduce Ll, c, and C2, but since reducing the latter CI and C2 reduces the output, it is necessary to reduce the former.

FIG. 4 shows a partial sectional view of a winding of a conventional pulse transformer.

In the figure, a low voltage winding 21 and a high voltage winding 22 are wound around insulating cylinders 23A and 23B having different diameters, respectively, and are attached to an iron core.
0 is inserted.

(Problem to be solved by the invention) However, in the pulse transformer 3 having such a configuration,
The leakage inductance L of the pulse transformer 3 greatly influences the stacked pressure of the windings, the number of turns (2 diameters), and the distance d between the high and low voltage windings 21 and 22.

However, in the conventional pulse transformer 3, the spacing d is
．． There is a limit due to the dielectric strength between the two.

Therefore, if multiple transformers are connected in parallel, the external size will increase.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a pulse transformer that is small and can generate high-frequency pulses.

[Structure of the Invention (Means and Effects for Solving the Problems) The present invention provides a pulse transformer that boosts a pulse voltage applied to the negative side, in which the winding of the transformer is twisted between two insulated wires. Consisting of insulated stranded wires, one of these insulated strands is divided into multiple equal parts and connected in parallel to serve as the primary winding, reducing leakage inductance and outputting small, high-frequency pulses. This is a pulse transformer that can

(Embodiment) Hereinafter, one embodiment of the pulse transformer of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a pulse transformer in which windings are wound around an iron core 20 with a turns ratio of 1:2 between primary and secondary coils.

That is, in FIG. 1, a stranded wire 30 made by twisting together an electric wire 31 with a thin insulation coating and an electric wire 32 with a thick insulation coating is wound around the iron core zO, and the electric wire 31 is cut at one-half of the total number of turns. The cut electric wires 31 are connected in parallel, and the winding start side is connected to a low voltage side U terminal, and the winding end side is also connected to a pulse power source (not shown) as a V terminal. The electric wire 32 has a U terminal on the winding start side and a V terminal on the winding end side connected to a secondary side capacitor (not shown).

FIG. 2 shows the connection diagram of FIG.

In Fig. 2, if the power flowing from the pulse power source 40 to the terminals u and v is 1, the current shunted to the wire 31 is I, /2, so the apparent primary winding is the secondary winding. Although they have the same number of turns, they are actually step-up transformers with a turns ratio of 1=2.

In this pulse transformer, since the same magnitude of current flows through the wires 32 and 31 of the stranded wires 30, the magnetic flux is completely canceled out, and as a result, the leakage magnetic flux is reduced, so the leakage inductance is extremely small. .

Further, since an insulating tube as in the conventional case is not required, a pulse transformer that is small and can obtain high-frequency pulses can be provided.

In the above embodiment, the step-up ratio is 1:2, but the step-up ratio can be further increased by increasing the number of wires 31 in parallel, and there is no need for an insulating tube, just winding the stranded wires 30. Since the number of parts is reduced, it is possible to obtain a pulse transformer that is easy to manufacture and reliable.

Further, in the above embodiment, when the secondary voltage is high, the stranded wire 30 may be vacuum impregnated with, for example, epoxy resin after being wound.

[Effects of the Invention] As described above, according to the present invention, in a pulse transformer that boosts the pulse voltage applied to the negative side, a stranded wire made by twisting two insulated wires is wound around the iron core of the transformer. Since one of the stranded wires is divided into a plurality of parts to form a plurality of parallel secondary windings, it is possible to obtain a pulse transformer that has low leakage inductance, is small, and can output high-frequency pulses.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the pulse transformer of the present invention, FIG. 2 is a connection diagram showing the operation of the pulse transformer of the present invention,
FIG. 3 is a connection diagram showing a conventional pulse transformer, and FIG. 4 is a partially detailed diagram showing the operation of the conventional pulse transformer. 20... Iron core 30... Twisted wires 31, 32
・・・Insulated wire

Claims (1)

[Claims] In a pulse transformer that boosts the pulse voltage applied to the primary side, the winding of the pulse transformer is composed of a stranded wire made by twisting two insulated wires together, and one of the stranded wires is A pulse transformer characterized in that one wire is equally divided into multiple parts and connected in parallel to form the primary winding.