JP2585719Y2 - Control circuit of DC stabilized power supply - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control circuit for a stabilized DC power supply having improved stability.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram of a control circuit of a stabilized DC power supply. An output voltage (current) setting device 1 having a highly stable reference power supply generates a set voltage signal Vs. The differential amplifier 3 in the control circuit responds to an actual output voltage (current) signal Vr obtained from the high-precision detector 2 that detects the output voltage (current) of the stabilized DC power supply. The output of the differential amplifying unit 1 is introduced into a proportional / integral operation unit 4 for giving a required response characteristic, and a control target of the DC stabilized power supply is adjusted by a control signal obtained from the operation unit, and a DC stabilized power supply is controlled. The output voltage (current) is kept constant.

[0003]

SUMMARY OF THE INVENTION In a stabilized DC power supply, a high stability, for example, a stability of 10 ^-5 is obtained (for example,
In order to suppress the fluctuation of the output voltage to about 10 V in the power supply of the 1 MV class ion accelerator, the differential amplifier 1 needs to have higher accuracy. This differential amplifying section is usually constructed by connecting resistors Rs and Rf to an operational amplifier OP as shown in FIG. 4, which determines use of a high-performance operational amplifier, input impedance, and amplification factor. Even if a resistor with a high degree of stability is required and the temperature of the entire control circuit is controlled, the resistor is in the PPM order (10 ^-6 order).
Temperature coefficient is required.

[0005] In addition, the proportional / integral operation unit 4 performs an integral operation, as shown in FIG.
A Miller integrating circuit type to which an integrating capacitor C is connected is used. In order to obtain a stability of 10 ^{-5 by} the integrating circuit, a DC gain of the order of 10 ⁵ is required. However, if the integration time constant is set so as to be 1 to 10 seconds, the values of the input resistance R and the integration capacitor C that can be generally considered are R = 100 kΩ to 1 MΩ and C = about 10 μF. , The internal resistance is limited to 3000 MΩ, so that the maximum DC gain is suppressed to 3000 to 30000 times,
It doesn't reach 0 ⁵ .

The present invention provides a control circuit capable of improving the stability of a DC stabilized power supply without using a particularly high-performance amplifier, resistor, or capacitor in a differential amplifier and an operation unit of the control circuit. It is intended to do so.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to a control circuit for a stabilized DC power supply having a differential amplifier and a proportional / integral calculator responsive to a set voltage signal and an actual output voltage signal.
A differential amplifier that responds to the set voltage signal and the actual output voltage signal; and an integrating circuit that responds to the output of the amplifier and supplies a correction signal to the differential amplifier. .

[0007]

Normally, the stabilizing power supply is 0.1% (10 ^{-3) with} respect to disturbance without using particularly high-performance operational amplifiers, resistors and capacitors in the differential amplifier and the proportional / integral calculator of the control circuit. )
A sufficient degree of stability can be obtained, and even under such stability, the stability of 10 ⁻⁵ is cleared instantaneously (within 〜１０10 seconds). A differential amplifier that responds to the set voltage signal and the actual output voltage signal, and an integration circuit that responds to the output of the amplifier.
The output voltage of the stabilized power supply is monitored for drift in the range of 0.1%, and the output of the integrator is supplied to the differential amplifier for correction.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of the control circuit. An output voltage (current) setting device 1 having a high-stability reference power supply has a set voltage signal Vs and an actual output voltage (current) from a high-precision detector 2 for detecting the output voltage (current) of the DC stabilized power supply. The signal Vr is introduced to the differential amplifier 3 in the control circuit. The output of the differential amplifying unit 1 is introduced to a proportional / integral calculating unit 4 for giving a required response characteristic, and a control target of the DC stabilized power supply is adjusted by a control signal of the calculating unit.

[0009] Even in such a control circuit, according to the current state of the art, in particular, without using a high-performance operational amplifier, a resistor, and a capacitor, a DC stabilized power supply is required.
Stability of about 1% (10 ^-3 ) can be easily obtained. Also,
Even if the stability is 0.1%, the stability of ^10-5 can be cleared instantaneously (within 10 seconds). The correction circuit unit 5 responds to the output voltage of the stabilized DC power supply, monitors the drift of the output voltage of the stabilized power supply in the range of 0.1% with the above-described control circuit, and corrects the drift.

The differential amplifier 6 of the correction circuit 5 has the same circuit type as that shown in FIG. 4 and responds to the set voltage signal Vs and the actual output voltage signal Vr to amplify the error between the two signals. I do. Since the correction circuit unit 5 corrects 0.1%, the differential amplifier 6 has a high amplification rate and amplifies the error by, for example, 1000 times. The integrating circuit 7 is configured by a Miller integrating circuit as in FIG. 5, integrates the error amplification output so as to eliminate the offset, and supplies the output to the differential amplifier 2 as a correction input. FIG. 2 shows an example of the correction signal injection mode, in which the non-inverting input circuit resistance R of the operational amplifier of the differential amplifier unit 1 is shown.
f is divided, and the correction signal from the integration circuit 7 is injected into the division point. If the value of the resistor that determines the amplification factor of the differential amplifier 6 changes, for example, by 1%, the output signal changes by 1%. However, when the error amplification output is set to zero, the error that appears on the input side is 10 ^−. It becomes ⁵ . Also, as for the integration circuit 7, since the amplification factor of the preceding stage is 1000 times, the DC
If there is an amplification factor of 0, a stability of 10 ^-5 can be realized, and these can be easily achieved with ordinary capacitors and resistors.

[0011]

According to the present invention, as described above, the drift of the output voltage of the stabilized power supply responding to the outputs of the differential amplifier and the proportional / integral calculator of the control circuit is caused by the setting voltage signal. And a differential amplifier that responds to the actual output voltage signal and an integrating circuit that responds to the output of the amplifier, monitor the output, and input the output of the integrating circuit to the differential amplifier section of the control circuit to correct it. The stability of the stabilized power supply can be as high as about 10 ^-5 without using particularly high-performance operational amplifiers, resistors, and capacitors in the section and the proportional / integral operation section.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a circuit diagram of an injection circuit of a correction signal.

FIG. 3 is a block diagram of a control circuit of a conventional stabilized DC power supply.

FIG. 4 is a configuration circuit diagram of a differential amplifier.

FIG. 5 is a circuit diagram of an integral operation unit.

[Explanation of symbols]

 1 Output voltage setting unit 2 Output voltage detector 3 Differential amplifier unit 4 Proportional / integral operation unit 5 Correction circuit unit 6 Differential amplifier 7 Integrator circuit

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G05F 1/10 302 G05F 1/10

Claims (1)

(57) [Scope of request for utility model registration] 1. A control circuit for a stabilized DC power supply having a differential amplifier and a proportional / integral calculator responsive to a set voltage signal and an actual output voltage signal, wherein the control circuit responds to the set voltage signal and an actual output voltage signal. 1. A control circuit for a stabilized DC power supply, comprising: a differential amplifier for performing the above operation; and an integrating circuit that responds to the output of the amplifier and supplies a correction signal to the differential amplifier.