JPH07245064A - Power source device for traveling wave tube - Google Patents

Abstract

PURPOSE:To reduce induced ripples without increasing the capacitor capacity of an output circuit in a power source device for a traveling wave tube. CONSTITUTION:By a transformer 3 driven by a high-frequency inverter 1, the secondary coil 340 of the transformer 3 is connected to a bridge rectification circuit 17 to be adopted as the cathode of a traveling wave tube 43 and a collector power source terminal. The secondary coil 340 of the transformer 3 is also connected to a multistage voltage doubler rectification circuit 45, and one end of output terminal of the circuit 45 is connected to a cathode and the other end is connected to a helix and also an earth 41. A first shield 330 arranged in the inner side of the secondary coil of the transformer 3 and secondary shields 350 and 351 arranged in the vicinity of an iron core facing at the outer side of the secondary coil are connected to the cathode output terminal 29 of the traveling wave tube. Floating electrostatic capacity Cs to the earth from the secondary coil 340 becomes almost zero since these shields 330, 350, and 351 of the secondary coil 340 are connected to the cathode output terminal 29 at a basic electric potential point/ Consequently, the value of high-frequency induced ripples can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device for a traveling wave tube,
In particular, it relates to a traveling-wave tube power supply device with reduced ripple.

[0002]

2. Description of the Related Art A traveling wave tube used for a microwave amplifier needs to heat a filament and supply a high voltage based on the cathode to each electrode, that is, collector, anode and helix. And these three types of high-voltage power supplies must be independently set and stabilized in voltage.

Generally, the helix electrode of a traveling-wave tube is grounded for convenience of adjustment and protection, so that a high voltage for the helix is reflectedly applied to the cathode. Therefore, the potential of the cathode is -5kV to -10kV with respect to the ground point.
The collector power supply, anode power supply, and filament power supply, which are floatingly charged at a high potential, are driven by a high-frequency inverter through an insulating transformer.

In the traveling-wave tube power supply device configured as described above, since the high frequency high voltage circuit is floatingly charged, the floating high frequency component flows to the ground through the floating electrostatic capacitance and then becomes a load. Return to the cathode potential of the power supply through the traveling wave tube. That is, the high frequency component is applied as an output ripple between the helix and the cathode of the traveling wave tube. Ripple of the power supply is undesirable because it causes spurious emission of the traveling wave tube, so it is necessary to reduce the ripple. In particular, since the transformer is driven at high frequency, ripples are generated in the helix output voltage by direct induction from the coil and high frequency current flowing through the floating electrostatic capacitance between the coil and the iron core.

In order to reduce the output ripple, there is a method of increasing the capacitance of the filter capacitor between the output terminals, but the capacitance of this capacitor increases the instantaneous current with respect to the traveling wave tube. It will also shorten the life of the pipe, which is not desirable.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to reduce inductive output ripple in a traveling wave tube power supply device without increasing the capacitance of the output circuit capacitor.

[0007]

In order to solve such a problem, the present invention provides a transformer driven by a high frequency inverter and a first rectifier circuit connected to a secondary winding of the transformer. , A cathode terminal and a collector terminal of the traveling wave tube connected to the output terminal of the first rectifier circuit, and a second rectifier circuit connected to the secondary winding of the transformer. In a traveling-wave tube power supply in which one end of the output terminal of the circuit is connected to the cathode of the traveling-wave tube and the other end of the output terminal is connected to the helix of the traveling-wave tube, inside the secondary winding of the transformer Connecting the disposed first shield and the second shield disposed outside the secondary winding and disposed near the opposing iron core to the cathode output terminal of the traveling wave tube. Is proposed.

[0008]

The secondary winding of the transformer is covered by the first and second shields, and the first and second shields are connected to the cathode output terminal at the reference potential point. The stray capacitance between ground and ground becomes almost zero, and the value of the high-frequency inductive ripple of the output voltage is significantly reduced. The second
The shield is placed only near the opposing cores,
The distributed capacitance of the secondary winding is suppressed to the necessary minimum, and the charging current to this distributed capacitance is kept low.

[0009]

FIG. 1 is a diagram showing a first embodiment of the present invention. This traveling wave tube power supply device 8 includes a high frequency inverter 1, a transformer 3, and a high voltage generator 6. A high-voltage circuit such as a rectifier circuit is housed in the high-voltage generating unit 6, is molded with silicone rubber 16, and is surrounded by a shield case 13.

Explaining the structure in detail, the high frequency inverter 1 is connected to the primary winding 2 of the transformer 3, and about 20
A high frequency of kHz is supplied. The secondary winding 340 of the transformer 3 is a bridge rectifier circuit 17 including diodes 19, 21, 23 and 25.
Connected to. A capacitor 27 is connected in parallel to the output terminal of the bridge rectifier circuit 17, the positive output is connected to the terminal 31, and the negative output is connected to the terminal 29. Further, the secondary winding 340 of the transformer 3 is simultaneously connected to the multistage voltage doubler rectifier circuit 45 including the capacitors 47, 49, 51, 53 and the diodes 55, 57, 59, 61. The negative output of the multistage voltage doubler rectifier circuit 45 is connected to the cathode output terminal 29 through the diode 21 in the bridge rectifier circuit 17, and the positive output is connected to the helix output terminal 33 through the diode 62. And terminal 29
A capacitor 28 is connected between the terminal and the terminal 33 to form a helix voltage ripple filter.

On the other hand, the traveling wave tube 43 comprises a filament 37, a cathode 39, a helix 36, and a collector 35. The filament 37 is supplied from an insulated power source (not shown), and the cathode 39 is connected to the cathode output terminal 29. ,helix
36 is connected to the helix output terminal 33, and the collector 36 is connected to the collector output terminal 31.

FIG. 2 is a diagram showing a cross section of the transformer 3. The structure of the transformer 3 will be described with reference to FIG.
The E-type ferrite core 301 and the I-type ferrite core 302 are combined to form a so-called EI core. On the center leg 301c of the E-shaped ferrite core 301, the primary winding 310 is wound with insulating paper between layers. Insulation tape 320 is wrapped around this outer circumference, and a thin copper plate is wound around the outer circumference for about one revolution.
To form. Both ends of this first shield 330 are close to or slightly overlap each other in order to obtain a sufficient shielding effect, but both ends thereof are not electrically contacted so as not to form a short circuit. Next, through the insulating paper between the layers 2
Wind the next winding 340. A thin copper plate is wound in an arc shape in the vicinity of the outer periphery facing the right leg portion 301a to form the second shield 350. Similarly, a thin copper plate is wound in an arc shape near the left leg 301b to form the second shield 351. Then, wrap the insulating tape 360 around the outermost circumference.

Here, the first shield 330 disposed inside the secondary winding 340 of the transformer 3 and the second shields 350 and 351 disposed outside thereof are insulated and covered by an electric wire to make a cathode output terminal 29 of the traveling wave tube 29. Connect to. In the traveling-wave tube power supply device 8 configured in this way, the high-frequency AC component that is induced from the secondary winding 340 of the transformer 3 and appears at the cathode output terminal 29 is as shown in FIG. It is configured as an equivalent circuit that divides the AC source e by the floating electrostatic capacitance Cs and the electrostatic capacitance Co of the capacitor 28. In the embodiment shown in FIG. 1 (a), the first shield 330 and the second shields 350, 351 connected to the cathode output terminal 29, which is the reference potential point, cause the floating static electricity from the secondary winding 340 of the transformer 3 to the ground point. Since the capacitance Cs becomes almost zero, the output ripple eo becomes an extremely small value.

While the second shields 350 and 351 act to reduce the above-mentioned stray capacitance Cs, they are arranged only near the right leg portion 301a and the left leg portion 301b of the E-shaped ferrite cores facing each other. , It acts to suppress the distributed electrostatic capacitance of the secondary winding 340 to a necessary minimum. The charging current to the distributed capacitance of the secondary winding 340 becomes reactive power, and it is preferable to keep this value small.

In the embodiment described above, the so-called EI core is used as the core of the transformer, but the present invention can be similarly applied to a transformer using a UU core or UI core of other shapes. In addition, the first shield 330 and the second shield 350,35
The material of 1 is not limited to a thin copper plate, but may be a thin copper foil, and any other thin conductive material can be used.

[0016]

Since the present invention has the characteristics described above, the output ripple can be reduced in the traveling-wave tube power supply device without increasing the capacitance of the output capacitor. Therefore, the energy stored between the output terminals is small and the inrush current value to the traveling wave tube is small, which is effective in preventing deterioration of the tube.

[Brief description of drawings]

FIG. 1 shows an embodiment of a traveling wave tube power supply device according to the present invention.

FIG. 2 shows a structure of a transformer in a traveling-wave tube power supply device according to the present invention.

[Explanation of symbols]

1 ... High frequency inverter 3 ... Transformer 6 ... High voltage generator 8 ... Traveling wave tube power supply 13 ... Shield case
16 ... Silicon rubber 17 ... Bridge rectifier circuit 19, 21, 23, 25 ... Diode 27 ... Capacitor 29 ... Cathode output terminal 31 ... Collector output terminal 33 ... Helix output terminal 35 ... Collector 36 ... Helix 37 ... Filament 39 ... Cathode 41 … Grounding 43… Traveling wave tube 45… Multi-stage voltage doubler rectifier 47, 49, 51, 53… Capacitor 55, 57, 59, 61, 62… Diode Cs… Stray capacitance 301… E type Ferrite core 302… I type Ferrite core 310… Primary winding 320… Insulating tape 330… First shield 340… Secondary winding 350,351… Second shield 360…
Insulating tape

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H02M 7/06 A 9180-5H 7/10 Z 9180-5H 7/48 Z 9181-5H 9/04 Z H05K 9/00 H (72) Inventor Masao Sato 1-1-18 Takada, Toshima-ku, Tokyo Inside Origin Electric Co., Ltd. (72) Takashi Yamashita 1-1-6 Uchisaiwai-cho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Inventor Yama ▲ Saki ▼ Mikio 1-1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Japan Telegraph and Telephone Corporation (72) Inventor Nobuhiro Takahashi 1-1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo No. Japan Telegraph and Telephone Corporation

Claims (1)

[Claims] 1. A transformer driven by a high frequency inverter, a first rectifier circuit connected to a secondary winding of the transformer, and a traveling wave tube connected to an output terminal of the first rectifier circuit. And a second rectifier circuit connected to the secondary winding of the transformer.
In the traveling-wave tube power supply device, one end of the output terminal of the rectifier circuit is connected to the cathode of the traveling-wave tube, and the other end of the output terminal is connected to the helix of the traveling-wave tube. The cathode of the traveling wave tube includes a first shield arranged inside the winding and a second shield arranged outside the secondary winding and arranged near the opposing iron core. A traveling-wave tube power supply device characterized by being connected to an output terminal.