Abstract: A time-of-flight mass spectrometry device includes an electrode to which a DC high voltage is applied in order to form an ion flight space and a high voltage power supply device that applies the high voltage to the electrode. The high voltage power supply device includes a high voltage generating circuit that generates the high voltage, and a voltage control circuit that is selectively set to a convergence responsiveness priority mode in which the high voltage generating circuit is controlled such that the high voltage has first convergence responsiveness and first stability or a stability priority mode in which the high voltage generating circuit is controlled such that the high voltage has second convergence responsiveness that is lower than the first convergence responsiveness and second stability that is higher than the first stability.

Abstract: A negative DC voltage is supplied to a flight tube from a negative voltage generator by turning on switching elements and turning off other switching elements during performance of a measurement, and a capacitor is charged by an auxiliary positive voltage generator by turning on a switching element. When an applied voltage is switched from a negative to a positive polarity, a large current is supplied to the flight tube from the capacitor by turning off the switching elements and turning on the switching element, and thus a capacitance is quickly charged to a positive potential. Thereafter, a stable positive DC voltage is applied to the flight tube from a positive voltage generator by turning off the switching element and turning on the switching element.

Abstract: A power supply device includes a power supply circuit, a casing, a mold resin and a grounding member. The casing is conductive. At least part of a circuit portion of the power supply circuit is stored in the casing. A resin injector is formed in the casing. A mold resin is injected from the resin injector to fill the casing and enclose the circuit portion. The grounding member is conductive. The grounding member is arranged in the casing to shield the resin injector from the circuit portion while being in contact with the mold resin.

Abstract: A power supply device includes a power supply circuit, a casing, a mold resin and a grounding member. The casing is conductive. At least part of a circuit portion of the power supply circuit is stored in the casing. A resin injector is formed in the casing. A mold resin is injected from the resin injector to fill the casing and enclose the circuit portion. The grounding member is conductive. The grounding member is arranged in the casing to shield the resin injector from the circuit portion while being in contact with the mold resin.

Abstract: A negative DC voltage is supplied to a flight tube from a negative voltage generator by turning on switching elements and turning off other switching elements during performance of a measurement, and a capacitor is charged by an auxiliary positive voltage generator by turning on a switching element. When an applied voltage is switched from a negative to a positive polarity, a large current is supplied to the flight tube from the capacitor by turning off the switching elements and turning on the switching element, and thus a capacitance is quickly charged to a positive potential. Thereafter, a stable positive DC voltage is applied to the flight tube from a positive voltage generator by turning off the switching element and turning on the switching element.