JP2856511B2 - Load current detection circuit for multi-output power supply circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a multistage traveling wave tube (TWT), for example.
The present invention relates to a multi-output power supply circuit used as a TWT power supply that generates a collector current for driving the power supply.

(Prior Art) A multi-output power supply circuit used as a conventional collector multi-stage TWT power supply is generally configured as shown in FIG.
In FIG. 3, the AC 11 is the voltage control converter, the converter 11 to enter the AC power, with respect to the primary winding m ₁ of the converter transformer 12, as needed across the terminals intermediate tap as a reference Apply pulse voltage. Here, both ends of the terminals of the secondary winding m ₂ of the converter transformer 12
A and B, and the intermediate tap is C.

First and second power supply circuits 13 and 14 are connected in parallel to the converter transformer 12. The first power supply circuit 13 includes rectifier diodes 131 and 132 and a smoothing capacitor 133. The anodes of the first and second rectifier diodes 131 and 132 are connected to the terminals A and B of the transformer 12, respectively, and the cathodes of the rectifier diodes 131 and 132 are connected to each other in common and connected to the intermediate tap C via the smoothing capacitor 133. .
The above-mentioned cathode common connection point is the first output terminal out ₁ as the first output terminal out ₁ .
Connected to the collector resistance 15 of the The other end of the resistor 15 is connected to the intermediate tap C.

On the other hand, the second power supply circuit 14 includes a diode bridge rectifier circuit 141, a pair of AC transmission capacitors 142 and 143, and a smoothing capacitor 144. Diode bridge rectifier circuit 1
41 has its AC input terminals b, c connected to terminals B, A. The reference terminal a of the rectifier circuit 141 is connected to the intermediate tap C of the converter transformer 12, and its DC output terminal d is connected to the intermediate tap C via the smoothing capacitor 144 and the smoothing capacitor 133. _second as out 2
Connected to the collector resistor 16 of The other end of the resistor 16 is connected to the intermediate tap C.

In the above configuration, in the first power supply circuit 13, assuming that the terminal A becomes (+) and the terminal B (-), the current output from the terminal A is rectified and smoothed by the diode 131 and the capacitor 133. Flows through the first collector resistor 15 as the collector current I ₁ of the intermediate tap C. Next, when the terminal A reverses to (-) and the terminal B reverses to (+), the current output from the terminal B is rectified and smoothed by the diode 132 and the capacitor 133, and the first collector current I ₁
Flows through the collector resistor 15 and is supplied to the intermediate tap C. Thereafter, this operation is repeated.

On the other hand, in the second power supply circuit 14, when the terminal A becomes (+) and the terminal B becomes (−), the current output from the terminal A passes through the first AC transmission capacitor 142, Rectified and smoothed by the smoothing capacitors 133 and 144, the second
Flows through the second collector resistor 16 as the collector current I2 of
It is supplied to the intermediate tap C. Next, when the terminal A reverses to (-) and the terminal B reverses to (+), the current output from the terminal B is rectified and smoothed by the rectifier circuit 141 and the smoothing capacitors 133 and 144 via the second AC transmission capacitor 143. , Flows through the second collector resistor 16 as the second collector current I ₂ , and is supplied to the intermediate tap C. Thereafter, this operation is repeated.

In the multi-output power supply circuit having the above configuration, when detecting the combined output current I ₁ + I ₂ , a current transformer 17 is conventionally provided on the output lines of the terminals A and B as shown in FIG. A voltage corresponding to the flowing current is detected, and the average value of the detected voltage is displayed on the current display 18. However, in the circuit shown in FIG. 3, not only the collector currents I ₁ and I ₂ but also an unnecessary current flows in the circuit.

That is, the terminal A is (+), the terminal B (-) at the (+) and the intermediate tap C is the terminal B, the current I ₃ which is output from the intermediate tap C rectifying circuit 141 and the second
Through the AC transmission capacitor 143 to the terminal B. Conversely, when the terminal A is (−) and the terminal B is (+), the intermediate tap C becomes (+) with respect to the terminal A, and the current I ₃ output from the intermediate tap C is supplied to the rectifier circuit 141 and the first It flows to the terminal A via the AC transmission capacitor 142.

Accordingly, the current I _T actually flowing through the current transformer 22 is _{I 1 + I 2 + I 3} . This total current I _T is I ₁ + I ₂ +
It is equivalent to I _2. FIG. 4 shows this state. Although the currents I ₁ and I ₂ flowing through the collector resistors 15 and 16 are rectified and smoothed DC currents, they are shown in FIG. 4 as AC waveforms for convenience of explanation, and the polarity is involved in the generation of the collector currents I ₁ and I _2. It depends on the direction of the flowing current in the current transformer. FIG (a) component of the current I _1, Fig. (B) component of the current I _2, FIG. (C)
The component of the current I _3, FIG. (D) shows the components of the composite current _{I T, (+), (} -) indicates the direction of the current.

As described above, when the output combined current is detected in the conventional multiple output power supply circuit, since the unnecessary current that is not output in the circuit is added, the detected current value is corrected and displayed by multiplying by the proportional constant. This method is high display quality when I ₁ and I ₂ does not vary. However, the values of the collector resistors 15 and 16 by replacement of TWT in this way, i.e. the load is changed, the resulting changes in I ₁ and I _2, since the change does not match the proportionality constant, a new proportionality constant It is necessary to readjust.

(Problems to be Solved by the Invention) As described above, in the conventional load current detection circuit of the multiple output power supply circuit, complicated adjustment is required every time the load is changed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned disadvantages, and an object of the present invention is to provide a load current detection circuit of a multi-output power supply circuit capable of detecting an output combined current with high accuracy even if the load changes due to load replacement or the like. With the goal.

[Means for Solving the Problems] To achieve the above object, a multi-output power supply circuit according to the present invention supplies different direct currents to first and second loads, respectively, and supplies the supplied loads. In detecting a current value, AC power is supplied to a primary winding, and a positive electrode is alternately applied to first and second terminals at both ends thereof based on an intermediate tap of a secondary winding according to a primary side AC input. A converter transformer that generates a negative or negative voltage; one electrodes of first and second rectifier diodes are connected to the first and second terminals, respectively; one end of a smoothing capacitor is connected to the intermediate tap; A first power supply circuit having the other end commonly connected to the other electrodes of the first and second diodes, and a first DC output terminal between the common connection end and the intermediate tap, to which the first load is connected; And the diode bridge A reference terminal of a rectifier circuit is connected to the intermediate tap, a pair of AC input terminals are respectively connected to the first and second terminals via an AC transmission capacitor, and a smoothing capacitor is a DC output terminal of the diode bridge rectifier circuit. A second power supply circuit to which the second load is connected, with a second DC output terminal between the connection point and the intermediate tap; a first diode of the first power supply circuit; The current flowing between the diode and one of the first and second terminals and the AC input terminal of the diode bridge rectifier circuit connected thereto is detected by a current transformer, and the detected output of the current transformer is loaded. And load current detecting means for converting the current value into a current value.

(Operation) In the load current detection circuit of the multi-output power supply circuit having the above-described configuration, each time the polarity of the first and second terminals of the converter transformer is alternately inverted in the first power supply circuit, the positive terminal and the intermediate tap are connected. The charging current flows from the positive terminal to the smoothing capacitor connected to the intermediate tap via the first or second diode, and is rectified and smoothed to a DC output, and supplied to the first load Is done. On the other hand, each time the polarities of the first and second terminals of the secondary winding of the converter transformer are inverted, the potential difference between the intermediate tap and the negative terminal causes the potential difference between the intermediate tap and the negative terminal via the diode bridge rectifier circuit. A charging current is supplied to the AC transmission capacitor on the positive side, and a discharge current is output from the AC transmission capacitor on the positive terminal side due to a potential difference generated between the positive terminal and the intermediate tap. This discharge current becomes a DC output of the diode bridge rectifier circuit, and is supplied to the second load after being smoothed by the smoothing capacitor. Therefore, the current flowing between the first diode and the second diode of the first power supply circuit and any one of the first and second terminals and the AC input terminal of the diode bridge rectifier circuit connected thereto. Is detected by a current transformer, and the detection output of the current transformer is converted into a load current value, whereby a current value proportional to the load current can be detected.

(Embodiment) An embodiment of the present invention will be described below with reference to FIG. 1 and FIG. However, in FIG. 1, the same parts as those in FIG. 3 are denoted by the same reference numerals, and different parts will be described here.

FIG. 1 shows the configuration. As is apparent from FIG. 1, the configuration of the power supply circuit itself is exactly the same as that of the conventional circuit shown in FIG. The difference is the installation location of the current transformer 17.

In other words, in this case, a first connection line between the cathode and the output terminal out ₁ of the rectifying diode 131 of the first power supply circuit 13, a second connection line between the cathode and the output terminal out ₁ of the rectifying diode 132, A third connection line between the second terminal B and the AC transmission capacitor 142 connected thereto,
As shown in the figure, the current transformer 17
Is provided, and the generated output of the current transformer 17 is led to the current indicator 18 to be converted into a load current value and displayed.

In the above configuration, when looking at the current waveform of each line, the first terminal A (+), the second terminals B (-) when a, first between the cathode and the output terminal out ₁ of the rectifying diode 131 As shown in FIG. 2 (a), the current flowing through the current transformer 17 in the direction indicated by the arrow (positive direction) is connected to the first connection line.
Ia flows. At this time, since the intermediate tap C has a positive potential with respect to the terminal B, the intermediate tap C, the rectifier circuit 141,
The current Ic is applied to the third connection line through the capacitor 142 to the terminal B (this value is from the terminal A via the capacitor 143 and the rectifier circuit 141 when the terminal A is (+) and the terminal B is (-). is smoothed by the smoothing capacitor 144, equal to the value of current that is a current I ₂ flowing through the collector resistor 16.) flows. Also,
Second between the cathode and the output terminal out ₁ of the rectifying diode 132
2B, a reverse voltage is applied to the polarity of the diode 132, so that the current Ib does not flow as shown in FIG. 2B. On the other hand, a current flows from the terminal B to the intermediate tap C via the AC transmission capacitor 143 and the rectifier circuit 141 through the third connection line between the second terminal B and the AC transmission capacitor 142 connected thereto. In the middle, a current Ic flows from below the arrow in the figure to above (negative direction). Thus, when the first terminal A is (+) and the second terminal B is (-), the currents Ia and Ic in the positive direction are supplied to the first and third lines.
It flows, in the second line since no current flows Ib, the current I _T, which is detected by the current transformer 17 is Ia + Ic as shown in FIG. 2 (d).

Conversely, the first terminal A is (-) and the second terminal B is (+).
When it becomes, to the first connection line between the cathode and the output terminal out ₁ of the rectifying diode 131, since the reverse voltage is applied with respect to the polarity of the diode 131, current as shown in FIG. 2 (a) Ia Does not flow. Further, a second connection line between the cathode and the output terminal out ₁ of the rectifying diode 132, a second
As shown in FIG. 2B, a current Ib flows from the lower side to the upper side (negative direction) of the current transformer 17 in the figure. On the other hand, the third connection line between the AC transmission capacitor 142 connected to the second terminal B and it AC transmission capacitor 142 from the second terminal B, the current Ic through the rectifier circuit 141 to the output out ₂ The current Ic flows through the current transformer 17 from below to above (negative direction) in the figure. Thus, when the first terminal A is (-) and the second terminal B is (+), the negative currents Ib and Ic flow through the second line and the third line, and the first line Does not flow the current Ia. Current I _T, which is detected by the current transformer 17 is Ib + Ic As shown in FIG. 2 (d).

Here, the amplitude values of Ia and Ib are the same, and the positive and negative amplitude levels of Ic are also the same. Therefore, the current transformer
The current detected at 17 is equivalently equal to I ₁ + I ₂ . Therefore, by averaging the detected voltage for each half cycle obtained by the current transformer 17 and displaying the averaged voltage on the current display 18, I ₁ , I ₁
The total value of ₂ is equivalently displayed, and the accuracy does not deteriorate due to a change in load.

In the above embodiment, both the first rectifier circuit 13 and the second rectifier circuit 14 extract current from the first and second terminals of the converter transformer 12, but when the output voltages are different, provided an appropriate intermediate tap on the secondary winding m ₂ depending on the ratio, it is sufficient to take out from separate locations. Further, the smoothing capacitor 144 of the second power supply circuit 14 is
It goes without saying that the same is true even if the connection is made between the DC output terminal d of 41 and the intermediate tap C.

[Effects of the Invention] As described above, according to the present invention, it is possible to provide a multi-output power supply circuit capable of accurately detecting an output combined current even when a load changes due to load replacement or the like.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of a multiple output power supply circuit according to the present invention, FIG. 2 is a waveform diagram for explaining the operation of the embodiment, and FIG. 3 is a configuration of a conventional multiple output power supply circuit. FIG. 4 is a waveform diagram for explaining the operation of the conventional circuit. 11 voltage control converter, 12 converter transformer, 13 first power supply circuit, 131, 132 rectifier diode, 133 smoothing capacitor, 14 second power supply circuit, 1
41 ... Diode bridge rectifier circuit, 142,143 ... AC transmission capacitor, 144 ... Smoothing capacitor, 15 ... First
Collector resistor, 16 ...... second collector resistors, 17 ...... current transformer, 18 ...... current indicator, I _1, I ₂ ...... collector current.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Nakajima 1 Koga Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture Inside the Toshiba Komukai Plant (72) Inventor Fumihiko Ogawa Komukai-Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa No. 1 Inside the Komukai Plant of Toshiba Corporation (56) References JP-A-50-55835 (JP, A) JP-A-54-101445 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB Name) H02M 1/00-9/06 H01J 23/34

Claims (2)

(57) [Claims] 1. A load current detection circuit for a multi-output power supply circuit for supplying different DC currents to first and second loads and detecting the supplied load current value, wherein AC power is supplied to a primary winding, A converter transformer that alternately generates a positive or negative voltage in response to a primary-side AC input to first and second terminals at both ends thereof based on an intermediate tap of the secondary winding; Of the rectifier diode are connected to the first and second terminals, one end of the smoothing capacitor is connected to the intermediate tap, and the other end is commonly connected to the other electrode of the first and second diodes. A first power supply circuit to which the first load is connected between the common connection terminal and the intermediate tap as a first DC output terminal; a reference terminal of a diode bridge rectifier circuit connected to the intermediate tap; AC input And a smoothing capacitor is connected to the DC output terminal of the diode bridge rectifier circuit, and a second direct current is connected between the connection point and the intermediate tap. A second terminal to which the second load is connected as an output terminal
And a first diode and a second diode of the first power supply circuit and any one of the first and second terminals and an AC input terminal of a diode bridge rectifier circuit connected thereto. Load current detection means for detecting a current flowing through each of the current transformers with a current transformer and converting a detection output of the current transformer into a load current value. 2. The load current detection circuit according to claim 1, wherein one end of the smoothing capacitor of the second power supply circuit is connected to an intermediate tap of the converter transformer.