JP2010066860A - High-voltage power supply unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-voltage power supply unit, capable of obtaining high noise reduction capability without degrading system response by adding a relatively simple circuit. <P>SOLUTION: With respect to securing low noise and high-speed response, the power supply unit includes a high-voltage generator, a filter connected to the output system of the high-voltage generator, and a floating amplifier connected to the successive stage of the filter. Between the input terminal and the output terminal of the floating amplifier, a diode parallel circuit is connected in parallel, so that there are mutually reverse polarities. A common potential point of the floating amplifier is buffered by another floating amplifier connected in the successive stage of the filter. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a high-voltage power supply device, and more particularly, to low noise and ensuring high-speed response.

  FIG. 7 is a circuit diagram showing a basic configuration example of a conventional high-voltage power supply device. In FIG. 7, a voltage dividing circuit composed of resistors R1 and R2 connected in series and a capacitor C1 are connected in parallel to the output terminal of the high voltage generator HV. The midpoint of connection of the voltage dividing circuit is fed back to the high voltage generator HV, and the high voltage generator HV generates a constant voltage of at least several hundred volts, for example. The capacitor C1 is connected to stabilize the output. The larger this value, the lower the noise.

  FIG. 8 shows a further noise reduction as compared with FIG. 7, and a resistor R3 is connected between one end of the resistor R1 and one end of the capacitor C1 constituting the voltage dividing circuit to form an RC filter. .

  FIG. 9 also achieves a lower noise than FIG. 7, and an LC filter is configured by connecting an inductance L1 between one end of a resistor R1 and one end of a capacitor C1 constituting the voltage dividing circuit. .

  Patent Document 1 discloses a configuration in which a CR filter circuit including filter resistors 6 and 7 and filter capacitors 8 and 9 is connected to the boost rectifier circuit 5.

JP 2006-215998 A

  However, in the case of the basic configuration example of FIG. 7, if the capacitor C1 is increased, the response of the system is deteriorated. As a result, problems such as being unable to follow load fluctuations and taking time to rise and fall occur.

  In the case where an RC filter is added as shown in FIG. 8, the constant increases when noise is removed to a low frequency. As a result, a voltage drop based on the load current occurs in the resistor R3, which causes a problem that the accuracy of the output voltage deteriorates.

  If an LC filter is added as shown in FIG. 9, the effect is reduced depending on the type of load, and in the worst case, there is a possibility of oscillation.

  The present invention has been made in view of these problems, and an object of the present invention is to provide a high-voltage power supply capable of obtaining a high noise removal capability without deteriorating the response of the system by adding a relatively simple circuit. To implement the device.

In order to solve such a problem, the invention of claim 1
A high pressure generator,
A filter connected to the output system of the high-pressure generator,
Floating amplifier connected after this filter,
And a high voltage power supply device.

The invention according to claim 2 is the high-voltage power supply device according to claim 1,
The filter includes a resistor and a capacitor.

The invention according to claim 3 is the high-voltage power supply device according to claim 1 or 2,
A diode parallel circuit connected in parallel so as to have opposite polarities is connected between the input terminal and the output terminal of the floating amplifier.

The invention according to claim 4 is the high-voltage power supply device according to any one of claims 1 to 3,
The common potential point of the floating amplifier is buffered by another floating amplifier connected to the subsequent stage of the filter.

The invention according to claim 5 is the high-voltage power supply device according to any one of claims 1 to 4,
The floating amplifier is driven by a floating power source in which a common potential point is separated into a front stage and a rear stage of the filter.

The invention described in claim 6 is the high-voltage power supply device according to claim 5,
A diode parallel circuit that is connected in parallel so as to have opposite polarities is connected between the common potential point before the filter and the common potential point after the filter in the floating power supply.

  As a result, a high-voltage power supply device that can obtain a high noise removal capability without degrading the response of the system can be obtained.

  The present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing a configuration example of a high-voltage power supply device according to the present invention, and the same reference numerals are given to the parts common to FIG. In FIG. 1, a floating amplifier U1 is added after the RC filter composed of a resistor R3 and a capacitor C1 provided for noise removal. Note that the connection point of the resistors R1 and R3 is connected to the common potential point G1.

  FIG. 2 is a circuit diagram of a floating power supply for driving the floating amplifier U1 of FIG. A commercial power source is connected to the primary winding of the power transformer T1. Between the terminals of the secondary winding, a first series circuit of capacitors C2 and C3 and a second series circuit of capacitors C4 and C5 are connected in parallel, and the first series circuit of capacitors C2 and C3 and the capacitor are connected. Three-terminal regulators REG1, REG2 are connected between the second series circuit of C4 and C5.

  That is, the input terminal of the regulator REG1 is connected to one end of the capacitor C2, the output terminal is connected to one end of the capacitor C4 and one power supply terminal VP of the floating amplifier U1, and the ground terminal is connected to the connection midpoint between the capacitors C2 and C3 and the capacitor. In addition to being connected to a connection midpoint between C4 and C5, it is connected to a common potential point G1.

  The input terminal of the regulator REG2 is connected to one end of the capacitor C3, the output terminal is connected to one end of the capacitor C5 and the other power supply terminal VN of the floating amplifier U1, the ground terminal is connected to the midpoint of connection between the capacitors C2 and C3, and the capacitor C4. In addition to being connected to the connection middle point of C5, it is connected to the common potential point G1.

  Each power supply terminal VP, VN of the floating amplifier U1 is connected to a common potential point via a capacitor.

  In such a configuration, the high voltage reduced in noise by the RC filter is buffered by the floating amplifier U1 and output as Vout.

  Here, by detecting the output voltage in front of the RC filter, the response speed of the system is not sacrificed.

  Further, since the load fluctuation is handled by the floating amplifier U1, a high-speed response can be realized.

  Further, since the filter and the load are separated, noise can be removed in a stable state without being affected by the load.

  Further, by using a filter composed of a resistor and a capacitor, stable characteristics can be obtained and the size can be reduced.

  And since amplifier U1 is comprised as a floating structure, the comparatively cheap operational amplifier generally marketed can be used.

  FIG. 3 is a circuit diagram showing another embodiment of the present invention, which is intended to protect the floating amplifier U1, and the same reference numerals are given to portions common to FIG. In FIG. 3, a first diode D1 and a second diode D2 are connected in parallel between the input terminal and the output terminal of the floating amplifier U1 so as to have opposite polarities.

  In such a configuration, for example, when the output of the high voltage generator HV suddenly stops due to a power failure or the load is short-circuited, the first diode D1 is connected between the input terminal and the output terminal of the floating amplifier U1. 3 and the second diode D2 are connected in parallel so as to have opposite polarities, the voltage between the input and output terminals of the floating amplifier U1 is the same as that of the first diode D1 and the second diode D2. Therefore, the floating amplifier U1 can be protected against an excessive voltage.

  In the configuration of FIG. 1, since the common potential point G1 of the floating amplifier U1 is a potential before noise is removed by the RC filter, a common mode rejection ratio (CMMR) of the floating amplifier U1 (CMMR: Common Mode Rejection Rratio). If the value is low, noise may not be sufficiently removed.

  This problem can be solved by buffering the quiet common potential point G2 after the noise is removed by the RC filter as shown in FIG. 4 with the floating amplifier U2 and setting it as the common potential point of the floating amplifier U1. Stable output can be obtained.

  That is, FIG. 4 is also a circuit diagram showing another embodiment of the invention, in which noise is reduced by improving the common potential point of the floating amplifier U1, and the same parts as in FIG. The sign is attached. In FIG. 4, the input terminal of the second floating amplifier U2 having the same configuration as that of the floating amplifier U1 is connected to the subsequent stage of the RC filter including the resistor R3 and the capacitor C1, and the output terminal is connected to the common potential point G2. ing.

  FIG. 5 is a circuit diagram of a floating power supply for driving the floating amplifiers U1 and U2 of FIG. 4, and the same reference numerals are given to the parts common to FIG. The difference between FIG. 5 and FIG. 2 is the connection of the common potential point. In other words, in the circuit of FIG. 2, the common potential point is one point of G1, and the ground point of each of the regulators REG1 and REG2 and the connection points of the capacitors C2 and C3 and the connection point of the capacitors C4 and C5 are the common potential point G1. It is connected to the. On the other hand, in the circuit of FIG. 5, only the midpoint of connection between the capacitors C2 and C3 is connected to the first common potential point G1, and the midpoint of connection between the ground terminals of the regulators REG1 and REG2 and the capacitors C4 and C5 is It is connected to the second common potential point G2.

  FIG. 6 is also a circuit diagram showing another embodiment of the invention, which is intended to protect the floating power supply of FIG. 5, and the same reference numerals are given to the parts common to FIG. In the circuit of FIG. 6, the diode parallel is connected in parallel between the first common potential point G1 and the second common potential point G2 so that the third diode D3 and the fourth diode D4 have opposite polarities. The circuit is connected.

  In the floating power supply of FIG. 5, if the potential difference between the first common potential point G1 and the second common potential point G2 increases due to some accident, the floating amplifiers U1 and U2 may be destroyed.

  In this case, as shown in FIG. 6, between the first common potential point G1 and the second common potential point G2, the third diode D3 and the fourth diode D4 are connected in parallel so as to have opposite polarities. Since the diode parallel circuit is connected, the potential difference between the first common potential point G1 and the second common potential point G2 is clamped by the third diode D3 and the fourth diode D4. The amplifiers U1 and U2 can be protected against an excessive voltage.

  In the above embodiment, an example in which a three-terminal regulator is used as a regulator has been described. However, the regulator is not limited to three terminals as long as it has an equivalent function.

  As described above, according to the present invention, by adding a relatively simple circuit, it is possible to realize a high-voltage power supply device that can obtain a high noise removal capability without deteriorating the response of the system. It is suitable as.

It is a circuit diagram which shows the structural example of the high voltage power supply device by this invention. FIG. 2 is a circuit example diagram of a floating power source for driving the floating amplifier U1 of FIG. It is a circuit diagram which shows the other Example of this invention. It is a circuit diagram which shows the other Example of this invention. FIG. 5 is a circuit example diagram of a floating power source for driving the floating amplifiers U1 and U2 of FIG. It is a circuit example figure which shows the other Example of this invention. It is a circuit diagram which shows the example of a basic composition of the conventional high voltage power supply device. It is a circuit diagram which shows the other structural example of the conventional high voltage power supply device. It is a circuit diagram which shows the other structural example of the conventional high voltage power supply device.

Explanation of symbols

HV High voltage generator R1-R3 Resistor C1-C5 Capacitor U1, U2 Floating amplifier REG1, REG2 3-terminal regulator G1, G2 Common potential point

Claims (6)

A high pressure generator,
A filter connected to the output system of the high-pressure generator,
Floating amplifier connected after this filter,
A high-voltage power supply device characterized by comprising:   The high-voltage power supply apparatus according to claim 1, wherein the filter includes a resistor and a capacitor.   3. The high-voltage power supply device according to claim 1, wherein a diode parallel circuit connected in parallel so as to have opposite polarities is connected between an input terminal and an output terminal of the floating amplifier.   The high-voltage power supply device according to claim 1, wherein the common potential point of the floating amplifier is buffered by another floating amplifier connected to a subsequent stage of the filter.   5. The high-voltage power supply device according to claim 1, wherein the floating amplifier is driven by a floating power source in which a common potential point is separated into a front stage and a rear stage of the filter.   A diode parallel circuit connected in parallel so as to have opposite polarities is connected between a common potential point before the filter and a common potential point after the filter in the floating power supply. Item 6. The high-voltage power supply device according to Item 5.

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