JP2014022075A - Power supply device, mass spectroscope, and power supply control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a power supply device that can output a DC high voltage of both positive and negative polarities, and that is suitable for downsizing.SOLUTION: A power supply device that can output a voltage of both positive and negative polarities, comprises: a transformer 5 whose secondary side coil is connected to an output terminal 6; a switching FET 1 switching a conduction state between one terminal of a primary coil of the transformer 5 and a system ground; a resonance capacitor 2 connected in parallel with the switching FET 1; a switching FET 3 switching a conduction state between the another terminal of the primary coil of the transformer 5 and the system ground; a resonance capacitor 4 connected in parallel with the switching FET 3; a switch 8 switching a conduction state between the one terminal of the primary coil and a control voltage source 7; and a switch 9 switching a conduction state between the another terminal and the control voltage source 7.

Description

  The present invention relates to a power supply device, a mass spectrometer, and a power supply control method, and more particularly to a configuration capable of outputting positive and negative power.

  2. Description of the Related Art Conventionally, a power supply device that can output by switching a positive voltage and a negative voltage from the same output terminal has been proposed. In such a power supply device, a primary side voltage is generated by an oscillation circuit, and a high voltage is obtained by a rectifier circuit boosted by a transformer and connected to the secondary side. Such a power supply device is used as a power source for a mass spectrometer that ionizes molecules in a sample to be analyzed, and performs mass separation using an electric field and a magnetic field to detect separated ions with a detector.

  As a method for ionizing molecules in a sample, an atmospheric pressure dielectric barrier discharge method is known. In this barrier discharge, a pulsed or sinusoidal high voltage is applied to a discharge part into which a sample is introduced to flow a discharge current, and molecules in the sample are ionized.

  As a circuit configuration of a high-voltage power supply used in such a mass spectrometer, a forward-type half-bridge pulse power supply and a push-pull pulse power supply are known (see, for example, Patent Document 1). In this method, two coils are provided in the primary side input section, power is supplied from the connection point, the current flowing through one of the coils is switched with a switching pulse, and the energy stored in the secondary side choke coil is loaded on the load side. It is a method to supply to.

JP 2006-519652 A

  The forward-type pulse power source requires two coils on the primary side in order to switch the current direction, resulting in a large circuit. In order to reduce the size of the apparatus, a configuration with only one coil is desired. In addition, since a high-voltage power supply waveform that is optimal for ionization, for example, positive and negative polarities, differs depending on the component of the substance contained in the sample to be analyzed, a power supply configuration that can output an optimal waveform corresponding to the substance is desirable. Such a problem is not limited to a power supply device applied to a mass spectrometer, but can be a problem in general power supply devices that can output positive and negative polarities.

  Therefore, an object of the present invention is to obtain a power supply device that can output a positive and negative DC high voltage and is suitable for miniaturization.

  In order to solve the above problems, an aspect of the present invention is a power supply device capable of outputting positive and negative voltage, a transformer 5 having a secondary coil connected to the output terminal 6, and a primary side of the transformer 5 Switching FET 1 for switching the conduction state between one terminal of the coil and system ground, resonance capacitor 2 connected in parallel with switching FET 1, and conduction between the other terminal of the primary coil of transformer 5 and system ground A switching FET 3 for switching the state, a resonance capacitor 4 connected in parallel with the switching FET 3, a switch 8 for switching the conduction state between one terminal of the primary coil and the control voltage source 7, and the other terminal and the control voltage And a switch 9 for switching a conduction state with the source 7.

  According to another aspect of the present invention, there is provided a mass spectrometer for performing mass analysis of a sample by flying an ionized sample in a decompressed space to which a voltage is applied and detecting the flight mode, the power supply device described above To apply a voltage to the decompression space.

  ADVANTAGE OF THE INVENTION According to this invention, the direct-current high voltage of both positive and negative poles can be output, and the power supply device suitable for size reduction can be obtained.

It is a figure which shows the circuit structure of the power supply device which concerns on Embodiment 1 of this invention. It is a timing chart which shows operation | movement of the power supply device which concerns on Embodiment 1 of this invention. It is a timing chart which shows operation | movement of the power supply device which concerns on Embodiment 1 of this invention. It is a figure which shows the circuit structure of the power supply device which concerns on Embodiment 2 of this invention. It is a timing chart which shows operation | movement of the power supply device which concerns on Embodiment 2 of this invention. It is a timing chart which shows operation | movement of the power supply device which concerns on Embodiment 2 of this invention. It is a block diagram which shows the structure of the mass spectrometer which concerns on Embodiment 3 of this invention. It is a flowchart which shows operation | movement of the mass spectrometer which concerns on Embodiment 3 of this invention. It is a figure which shows the circuit structure of the power supply of a flyback system.

Embodiment 1 FIG.
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration of a high voltage generation circuit according to the present embodiment. As shown in FIG. 1, the power supply device according to this embodiment is based on a flyback type high voltage generation circuit. First, the flyback method will be described with reference to FIG. FIG. 9 is a diagram illustrating a general circuit configuration of the flyback method. As shown in FIG. 9, a typical flyback circuit includes a switching field effect transistor (FET) 1, a resonance capacitor 2, and a transformer 5. The transformer 5 includes a primary side coil and a secondary side coil.

  One feature of the flyback method is that the number of components is small. Next, the operation of the circuit shown in FIG. 9 will be described. When the switching clock signal input to the gate of the switching FET 1 is at a high level, the switching FET 1 is turned on, current flows from the control voltage source 7 through the primary side coil of the transformer 5, and energy is accumulated in the primary side coil. Is done.

  Next, when the switching clock signal input to the gate of the switching FET 1 falls to a low level, the FET 1 is turned OFF, and the current flowing from the control voltage source 7 to the switching FET 1 becomes zero, and is stored in the primary side coil of the transformer 5. The energy is charged in the resonance capacitor 2. As a result, the point A potential on the primary side of the transformer 5 increases. Thereafter, the electric charge of the resonance capacitor 2 flows to the primary coil of the transformer 5, and the potential at the point A decreases to zero.

  As described above, when a current flows through the primary side coil of the transformer 5 by the potential at the point A increased by the on / off control of the switching FET 1, a high voltage output corresponding to the number of turns of the primary side coil and the secondary side coil is obtained. Obtained on the secondary side. FIG. 9 shows voltage waveforms of main parts. As shown in FIG. 9, when the signal input to the gate of the switching FET 1 is switched from the high level to the low level, the waveform of the potential at the point A becomes high, and the secondary side voltage output is obtained accordingly. In the circuit having the configuration shown in FIG. 9, a positive high voltage waveform is obtained on the secondary side by the on / off control of the switching FET 1.

  FIG. 1 is a diagram showing a circuit configuration of a power supply device according to this embodiment in which the flyback method as described in FIG. 9 is minimized. As shown in FIG. 1, in the power supply device according to the present embodiment, the switching FET 1 is connected to one end side of the primary coil of the transformer 2, and the switching FET 3 is connected to the other end side. That is, the switching FET 1 is used as the first switching circuit, and the switching FET 3 is used as the second switching circuit.

  Similar to the switching FET 1, a resonance capacitor 4 is connected to the switching FET 3. That is, the resonance capacitor 2 is used as the first capacitor, and the resonance capacitor 4 is used as the second capacitor. Further, both ends of the primary side coil of the transformer 2 are connected to the control voltage source 7 via the switch 8 and the switch 9, respectively.

  The switches 8 and 9 have control terminals 8a and 9a, respectively, and switch the connection / disconnection state between the control voltage source 7 and the primary coil of the transformer 2 based on a control signal input to the control terminals 8a and 9a. . That is, the switch 8 is used as the first power supply switching unit, and the switch 9 is used as the second power supply switching unit. When the control signal input to the control terminals 8a and 9a is in the high state, the switches 8 and 9 respectively connect the control voltage source 7 and the primary coil of the transformer 5 and when the control signal is in the low state, the switch 8 and 9 turn off the control voltage source 7 and the primary coil of the transformer 5, respectively.

  Next, the operation of the circuit shown in FIG. 1 will be described. FIG. 2A is a timing chart showing signal states of respective parts when a positive high voltage waveform is output to the secondary side. In the case of FIG. 2A, as a premise, the switch 8 is turned on, the switch 9 is turned off, and the side connected to the switching FET 3 among both ends of the primary side coil of the transformer 5 is connected to the control voltage source 7. It is in the state. Thereby, the output voltage of the control voltage source 7 is applied to the point B in FIG.

In this case, as shown in FIG. 2A, a switching clock signal is input to the gate of the switching FET 1, and the switching FET 1 performs a switching operation. On the other hand, a low signal is always input to the gate of the switching FET 3, and the switching FET 3 is always in the off state. As a result, when the signal input to the gate of the switching FET 1 is high level, the switching FET 1
n, current flows from the control voltage source 7 to the primary side coil of the transformer 5 via the point B, and energy is accumulated in the primary side coil.

  Next, when the signal input to the gate of the switching FET 1 falls to the low level, the switching FET 1 is turned off, and the current flowing from the control voltage source 7 to the switching FET 1 becomes zero. As a result, the resonance capacitor 2 is charged by the energy stored in the primary coil of the transformer 5, and the potential at point A in FIG. Thereafter, the electric charge of the resonance capacitor 2 flows through the primary side coil of the transformer 5, whereby the potential at the point A decreases and becomes zero. In this way, a current flows through the primary side coil of the transformer 5 due to the point A potential increased by the switching operation of the switching FET 1, and a positive high voltage output is obtained at the output terminal 6 connected to the secondary side coil of the transformer 5. It is done.

  FIG. 2B is a timing chart showing signal states of respective parts when a negative high voltage waveform is output to the secondary side. In the case of FIG. 2B, as a premise, the switch 8 is turned off, the switch 9 is turned on, and the side connected to the switching FET 1 among both ends of the primary side coil of the transformer 5 is connected to the control voltage source 7. It is in the state. Thereby, the output voltage of the control voltage source 7 is applied to the point A in FIG.

In this case, as shown in FIG. 2B, a switching clock signal is input to the gate of the switching FET 3, and the switching FET 3 performs a switching operation. On the other hand, a low signal is always input to the gate of the switching FET 1, and the switching FET 1 is always in the off state. As a result, when the signal input to the gate of the switching FET 3 is at a high level, the switching FET 3
n, current flows from the control voltage source 7 to the primary side coil of the transformer 5 via the point A, and energy is accumulated in the primary side coil.

  Next, when the signal input to the gate of the switching FET 3 falls to the low level, the switching FET 3 is turned off, and the current flowing from the control voltage source 7 to the switching FET 3 becomes zero. As a result, the resonance capacitor 4 is charged by the energy stored in the primary coil of the transformer 5, and the potential at point B in FIG. 1 rises. Thereafter, the electric charge of the resonance capacitor 4 flows to the primary coil of the transformer 5, so that the potential at the point B decreases and becomes zero. In this way, a current flows through the primary side coil of the transformer 5 due to the B point potential raised by the switching operation of the switching FET 3, and a negative high voltage output is obtained at the output terminal 6 connected to the secondary side coil of the transformer 5. It is done.

  As described above, in the circuit shown in FIG. 1, the switch 9 and the switching FET 3 are turned off, the switch 8 is turned on, and a clock is input to the switching FET 1 to obtain a positive high voltage. On the other hand, when the switch 8 and the switching FET 1 are turned off and the switch 9 is turned on and the clock is input to the switching FET 9, a negative high voltage is obtained. For this reason, it is possible to easily switch between positive and negative high voltages. In the present embodiment, the winding directions of the primary side and secondary side coils of the transformer 5 are opposite to each other. However, the same direction may be used. In this case, the switch 9 and the switching FET 9 are turned off, and the switch 8 is turned on and a clock is input to the switching FET 1 to obtain a negative high voltage. On the other hand, the switch 8 and the switching FET 1 are turned off, the switch 9 is turned on, and the clock is input to the switching FET 9. High voltage is obtained.

FIG. 3 is a timing chart showing signal states when the plus high voltage output and the minus high voltage output are alternately output in the circuit shown in FIG. Period _{T 1} in FIG. 3 is a period of off on, the switch 9 to switch 8, the period of _{T 2} are a period for on off, a switch 9 switches 8. Then, in a period of _{T 1,} inputs a clock signal to the gate of the switching FET1, inputs a low signal to the gate of the switching FET 9. Thereby, a positive high voltage is obtained at the secondary side voltage output at the timing when the gate input of the switching FET 1 changes from high to low.

On the other hand, in the period T ₂ , a clock is input to the gate of the switching FET 9 and a low signal is input to the terminal 3 of the switching FET 1. Thereby, a positive high voltage is obtained at the secondary side voltage output at the timing when the gate input of the switching FET 9 changes from high to low. By doing so, it is opposite in every cycle the current direction flowing through the primary side coil of the transformer 5, an output terminal connected to the secondary coil of the transformer 5 by an increase in the point A potential at a period of time T ₁ 6, a positive high voltage is output, and a negative high voltage is output to the output terminal 6 connected to the secondary coil of the transformer 5 due to an increase in the potential at the point B in the period T _2. As a result, an AC waveform in which a positive output and a negative output are alternately output is obtained.

  As described above, in the present embodiment, a flyback power source having a small number of parts is used, and a flyback power source is connected to both ends of the primary side coil of the transformer 5. A power supply device that can output voltage and is suitable for downsizing can be obtained.

Embodiment 2. FIG.
In the present embodiment, a specific example of the switches 8 and 9 in the first embodiment will be described. In addition, about the structure which attaches | subjects the same code | symbol as Embodiment 1, it shall show the part which is the same as that of Embodiment 1, or an equivalent part, and abbreviate | omits detailed description.

  FIG. 4 is a circuit diagram showing a configuration when the switches 8 and 9 in the first embodiment are realized using FETs. As shown in FIG. 4, the switch 8 includes FETs 81 and 82 in which gates are commonly connected to each other and sources are commonly connected to each other, and the commonly connected gates are respectively used as control terminals 10. Are used as input and output terminals. Similarly, the switch 9 is composed of FETs 91 and 92 whose gates are commonly connected to each other and whose sources are commonly connected to each other. The commonly connected gate is a control terminal 11 and each drain is input. Used as an output terminal.

  As described above, an instantaneous pulse voltage is applied between the control voltage source 7 and both ends of the primary side coil of the transformer 5 by the switching operation of the switching FET 1 or the switching FET 3. For this reason, for example, when a single FET is used as a switch, even if the FET is turned off by a control signal input to the gate, the FET can be operated unexpectedly by a pulse voltage applied to the source or drain. There is sex. On the other hand, as shown in FIG. 4, the pulse voltage is applied by the switching operation of the switching FET 1 or the switching FET 3 by using the drains of the two FETs having the sources connected in common as the input and output terminals. Only the drain of one FET, even if one FET unexpectedly turns on, the other FET maintains the off state, preventing unexpected operation of the switches 8 and 9 and stable switch operation Can be realized.

  FIGS. 5A and 5B are timing charts showing signal states of respective units when outputting a positive high voltage and a negative high voltage, respectively, and FIGS. 2A and 2B in the first embodiment. ). 5 (a) and 5 (b), in addition to the signals shown in FIGS. 2 (a) and 2 (b), inputs are made to control terminals 10 and 11 for on / off control of the switches 8 and 9. The signal to be shown is shown.

  As shown in FIG. 5A, when the switch 8 is turned on and the switch 9 is turned off, the control signal applied to the terminal 10 is set to the high level, and the control signal applied to the terminal 11 is set to the low level. On the other hand, as shown in FIG. 5B, when the switch 8 is turned off and the switch 9 is turned on, the control signal applied to the terminal 10 is set to the low level, and the control signal applied to the terminal 11 is set to the high level. . By providing such a control signal, a desired operation as described in the first embodiment can be performed.

  FIG. 6 is a timing chart showing signal states when the plus high voltage output and the minus high voltage output are alternately output in the circuit shown in FIG. 4 and corresponds to FIG. 3 in the first embodiment. In FIG. 6, in addition to the signals shown in FIG. 3, signals input to the control terminals 10 and 11 for on / off control of the switches 8 and 9 are shown.

As shown in FIG. 6, in a period _{T 1,} to off the FET91,92 well as on the FET81,82, a high signal is applied to the control signal of the control terminal 10, low on the control signal of the control terminal 11 Apply a signal. On the other hand, in a period _{T 2,} to apply a high signal to the control signal of the control terminal 11 together to on the FET91,92 and off the FET81,82, it applies a low signal to the control signal of the control terminal 10. By the control as shown in FIG. 6, the positive output and the negative output are alternately output to the output terminal 6 connected to the secondary side coil of the transformer 5 similarly to the operation described in FIG. 3 of the first embodiment. AC waveform can be obtained.

Embodiment 3 FIG.
In the present embodiment, a mass spectrometer using the power supply device 100 described above will be described. FIG. 7 is a block diagram showing the configuration of the mass spectrometer according to the present embodiment. As shown in FIG. 7, the high voltage output from the output terminal 6 of the power supply apparatus 100 is supplied to the ionization unit 101, and molecules in the sample to be analyzed are ionized by barrier discharge, and ions 101a are formed in the decompressed space. Is guided to the detection unit 102. That is, a voltage is applied to the reduced pressure space by the power supply device 100. The detection unit 102 detects the ions 101 a introduced from the ionization unit 101 and inputs the detection results 102 a to the control unit 103.

  Further, the control unit 103 outputs a switching clock signal input to the gates of the switching FETs 1 and 3 described in FIG. 1 and a control signal input to the control terminals 10 and 11 described in FIG. The control unit 103 switches these signals according to the detection result 102 a input from the detection unit 102, and switches the state of power supplied to the application unit 101. Specifically, three types of a positive high voltage state, a negative high voltage state, and a state in which the positive high voltage and the negative high voltage are alternately switched are switched according to the detection result 102a by the detection unit 102.

  As described above, the control unit 103 according to the present embodiment can perform efficient ionization and ion detection by switching the pulse polarity of the power source according to the component of the substance contained in the sample to be analyzed. Further, in the present embodiment, the apparatus can be miniaturized by using the flyback type high voltage power supply described above.

  Next, the operation of the mass spectrometer shown in FIG. 7 will be described with reference to FIG. As shown in FIG. 8, first, control unit 103 outputs a control signal for generating a positive pulse described in FIG. 2A of the first embodiment, and generates a positive pulse to power supply device 100. (S801), and ion detection by the detection unit 102 is performed (S802). As a result, if ions can be detected from the detection result 102a received from the detection unit 102 (S803 / YES), the control unit 103 stores and displays the type of detection ions and the like and ends (S804).

  When ions cannot be detected (S803 / NO), the control unit 103 outputs a control signal for generating the minus side pulse described in FIG. A side pulse is generated (S805), and ion detection is performed by the detection unit 102 (S806). As a result, if ions can be detected from the detection unit 102 based on the reception result 102a (S807 / YES), the control unit 103 stores and displays the type of detected ions and the like and ends (S808).

  When ions cannot be detected (S807 / NO), the control unit 103 outputs a control signal for alternately generating the positive side pulse and the negative side pulse described in FIG. The positive side pulse and the negative side pulse are alternately generated in 100 (S809), and ion detection is performed by the detection unit 102 (S810). As a result, if ions can be detected from the detection unit 102 based on the reception result 102a (S811 / YES), the control unit 103 stores and displays the type of detected ions and the like and ends (S812). On the other hand, if no ions can be detected (S811 / NO), the control unit 103 displays that the assumed substance is not present in the sample (S813) and ends.

  By such control, it becomes possible to suitably detect ions by power control according to the ions to be detected. Note that the order of pulse generation is not limited to the order described with reference to FIG. 8, and the same effect can be obtained regardless of the polarity of the pulse.

1 Switching FET
2 Resonant capacitor 3 Switching FET
4 Resonant capacitor 5 Transformer 6 Output terminal 7 Control voltage source 8, 9 Switch 10, 11 Control terminal 81, 82, 91, 92 FET
101 power supply device 101 ionization unit 102 detection unit 103 control unit

Claims (5)

A power supply device capable of outputting positive and negative voltage,
A transformer having a secondary coil connected to the output terminal;
A first switching circuit that switches a conduction state between the first terminal, which is one terminal of the primary coil of the transformer, and the system ground according to a control signal;
A first capacitor connected in parallel with the first switching element;
A second switching circuit that switches a conduction state between the second terminal, which is the other terminal of the primary coil of the transformer, and the system ground according to a control signal;
A second capacitor connected in parallel with the second switching element;
A first power supply switching unit that switches a conduction state between the first terminal and the control voltage source according to a control signal;
A second power supply switching unit that switches a conduction state between the second terminal and the control voltage source according to a control signal;
In the case of outputting a positive voltage, the first power supply switching unit makes the first terminal and the control voltage source conductive, and the second power supply switching unit is connected to the second terminal. The control voltage source is turned off, and the second switching circuit is switched to switch the conduction state between the second terminal and the system ground at a predetermined interval, thereby passing a current through the primary coil. ,
In the case of outputting a negative voltage, the second power supply switching unit makes the second terminal and the control voltage source conductive, and the first power supply switching unit is connected to the first terminal. The control voltage source is turned off, and the first switching circuit is switched to switch the conduction state between the first terminal and the system ground at a predetermined interval, thereby passing a current through the primary coil. A power supply device characterized by that.   The first power supply switching unit and the second power supply switching unit each have two FET elements whose sources are connected in common, and the drain of one FET element is connected to the control voltage source side. The power supply apparatus according to claim 1, wherein a drain of the other FET element is connected to the primary coil side. A mass spectrometer that conducts mass analysis of the sample by flying an ionized sample in a decompressed space to which a voltage is applied and detecting the flight mode,
A mass spectrometer that applies a voltage to the decompressed space by the power supply device according to claim 1.   4. The mass spectrometer according to claim 3, wherein the power supply device performs mass analysis of the material by alternately outputting the positive electrode voltage and the negative electrode voltage. 5. A power supply control method capable of outputting positive and negative voltage,
When outputting the positive voltage,
The first terminal, which is one terminal of the primary coil of the transformer whose secondary side coil is connected to the output terminal, and the control voltage source are brought into conduction, and the other terminal of the primary side coil A second terminal and the control voltage source are in a non-conductive state;
A switching circuit that switches a conduction state between the second terminal and the system ground according to a control signal to perform a switching operation to switch a conduction state between the second terminal and the system ground at a predetermined interval; A current is passed from the capacitor connected in parallel to the primary coil,
When outputting the negative voltage,
The second terminal and the control voltage source are in a conductive state, and the first terminal and the control voltage source are in a non-conductive state,
A switching circuit that switches a conduction state between the first terminal and the system ground according to a control signal to perform a switching operation to switch the conduction state between the first terminal and the system ground at a predetermined interval; A power supply control method, wherein a current is caused to flow from a capacitor connected in parallel to the primary coil.

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