Abstract: Provided is a power supply unit that includes a power factor correction circuit, a synchronizing signal generator, an alternating-current signal generator. The power factor correction circuit is configured to generate, based on a first alternating-current signal, a direct-current signal. The synchronizing signal generator is configured to generate, based on the first alternating-current signal, a synchronizing signal that is in synchronization with the first alternating-current signal. The alternating-current signal generator includes a switching section, and is configured to generate, based on the direct-current signal, a second alternating-current signal. The switching section is configured to perform, based on the synchronizing signal, a switching operation. The second alternating-current signal has a variable effective voltage value.

Abstract: Provided is a power supply unit that includes a switching section and a controller. The switching section is configured to perform a switching operation and thereby generate, based on an input signal, a first alternating-current signal. The controller is configured to control the switching operation and thereby perform an amplitude control that involves increasing, based on an input current in the switching section, a signal amplitude of the first alternating-current signal.

Abstract: Provided is a heater controlling unit that includes: a power factor correction circuit configured to convert a first alternating-current voltage supplied from a power supply into a direct-current voltage; an inverter configured to generate a second alternating-current voltage from the direct-current voltage converted by the power factor correction circuit; and a heater to which the second alternating-current voltage generated by the inverter is applied.

Abstract: A heater control device includes a power factor correction circuit configured to convert an alternate current voltage from a commercial power source to a direct current voltage; an inverter configured to generate a specific alternate current voltage from the direct current voltage converted with the power factor correction circuit; a heater configured to receive the specific alternate current voltage generated with the inverter; and an excessive temperature rise preventing portion configured to interrupt the specific alternate current voltage generated with the inverter from being supplied to the heater.

Abstract: Provided is a heater controlling unit that includes: a power factor correction circuit configured to convert a first alternating-current voltage supplied from a power supply into a direct-current voltage; an inverter configured to generate a second alternating-current voltage from the direct-current voltage converted by the power factor correction circuit; and a heater to which the second alternating-current voltage generated by the inverter is applied.

Abstract: A power supply device includes a voltage output unit configured to output a DC voltage corresponding to a control signal from a first controller and an output evaluator configured to perform a judgment process of judging whether or not the DC voltage is a voltage corresponding to a set value received from the fist controller, and to output a result of the judgment to the first controller. The output evaluator includes a storage for storing correspondence information which shows a correspondence relationship between the set value and a voltage value of the DC voltage outputted from the voltage output unit. The output evaluator performs the judgment process by outputting the correspondence information to the first controller, and receiving a set value determined on the basis of the correspondence information from the first controller.

Abstract: A power-supply device includes: a rectifier circuit configured to output a rectified voltage by rectifying an output from a transformer; a comparator circuit configured to compare a comparison voltage corresponding to an output voltage or an output current that are generated based on the rectified voltage with the indicator voltage and to control an operation of the transformer drive circuit so as to reduce the difference between the comparison voltage and the indicator voltage; a constant voltage element configured to limit the output voltage or the output current by operating as a constant voltage source when the value of the output voltage or the output current reaches a threshold; and a current mirror circuit. The current mirror circuit is configured to lower the indicator voltage by allowing a current proportional to the current flowing through the constant voltage element to flow through the current path.

Abstract: A power supply apparatus includes an arithmetic unit configured to successively update a N-bit division ratio at every step whose processing timing is managed by a timer, by adding or subtracting of preset data read from a data memory to or from the N-bit division ratio in accordance with a comparative output. An arithmetic unit performs an arithmetic operation to make a feedback data value approach a target data value by a negative feedback control, the arithmetic operation using, as the preset data, data read from the address specified by data with a predetermined bit width of M (M<N) extracted from the successively updated N-bit division ratio.

Abstract: A power supply with a digital control circuit generates an output voltage by driving a piezoelectric transducer with an alternating current voltage at a digitally controlled driving frequency. To skip over a spurious frequency, the driving frequency is switched between a first range above the spurious frequency and a second range below the spurious frequency. Within the first and second ranges, the driving frequency is varied in directions that make the output voltage track a target voltage. If the driving frequency arrives at the lower limit of the first range, it jumps to a switchover frequency in the second range. The first range can be used to generate a comparatively low output voltage, and the second range to generate a comparatively high output voltage.

Abstract: A piezoelectric transducer driver configured to drive a piezoelectric transducer for converting an inputted alternating-current voltage, includes: a drive circuit configured to generate the alternating-current voltage to be inputted into the piezoelectric transducer; a frequency controller configured to control a frequency of the alternating-current voltage as a drive frequency to be applied to the piezoelectric transducer; and a pulse generation circuit configured to generate a drive pulse having a switching frequency corresponding to the drive frequency, and to output the drive pulse to the drive circuit. The drive circuit includes a switching element configured to generate the alternating-current voltage by executing a switching operation corresponding to a pulse width of the drive pulse, and the pulse generation circuit changes the pulse width depending on the switching frequency.

Abstract: A power-supply device includes: a rectifier circuit configured to output a rectified voltage by rectifying an output from a transformer; a comparator circuit configured to compare a comparison voltage corresponding to an output voltage or an output current that are generated based on the rectified voltage with the indicator voltage and to control an operation of the transformer drive circuit so as to reduce the difference between the comparison voltage and the indicator voltage; a constant voltage element configured to limit the output voltage or the output current by operating as a constant voltage source when the value of the output voltage or the output current reaches a threshold; and a current mirror circuit. The current mirror circuit is configured to lower the indicator voltage by allowing a current proportional to the current flowing through the constant voltage element to flow through the current path.

Abstract: A high-voltage power-supply apparatus comprises a controller configured to output a control signal containing a pulse with a variable drive frequency; a switching unit configured to be switched by the control signal and output a drive signal; a piezoelectric transducer having a predetermined resonant frequency, and configured to be driven by the drive signal and output a high-voltage output voltage; a current detector configured to detect an electric current of a load connected to an output side of the piezoelectric transducer and output a current-detection result; and a lower-limit-value setup unit configured to set a frequency lower limit value for the drive frequency of the controller. The controller is configured to vary the frequency lower limit value in accordance with the current-detection result.

Abstract: A step-up transformer includes main, auxiliary, and secondary windings. The secondary winding steps up the voltage across the main winding. A rectifier rectifies the voltage across the secondary winding into a high-voltage output. A voltage converter produces a feedback signal from the high-voltage output, the feedback signal reflecting the magnitude of the high-voltage output. An integrator receives the feedback signal and a reference signal indicative of a target high-voltage output. A DC power supply supplies drain current into a field effect transistor (FET). The auxiliary winding has one end that receives the output of the integrator and the other end that outputs an AC voltage to a differentiator. The differentiator has a resistor connected between the gate of the FET and the ground, and a parallel circuit of a resistor and a capacitor, the parallel circuit connecting between the auxiliary winding and the gate of the FET.

Abstract: A piezoelectric transformer driving device includes a piezoelectric transformer for outputting an alternating high voltage, a switching control part configured to control the control frequency of the control signal, a reference voltage waveform generation part configured to switch between a first voltage value, a second voltage value and a third voltage value, a monitor voltage generation part configured to generate a monitor voltage waveform based on the high voltage output from the piezoelectric transformer, and a comparison part configured to compare the reference voltage waveform with the monitor voltage waveform to generate a comparison result, and configured to supply the comparison result to the switching control part.

Abstract: A high-voltage power-supply apparatus comprises a controller configured to output a control signal containing a pulse with a variable drive frequency; a switching unit configured to be switched by the control signal and output a drive signal; a piezoelectric transducer having a predetermined resonant frequency, and configured to be driven by the drive signal and output a high-voltage output voltage; a current detector configured to detect an electric current of a load connected to an output side of the piezoelectric transducer and output a current-detection result; and a lower-limit-value setup unit configured to set a frequency lower limit value for the drive frequency of the controller. The controller is configured to vary the frequency lower limit value in accordance with the current-detection result.

Abstract: A power unit includes: a frequency divider to divide a clock signal in a second frequency-division ratio based on a first frequency-division ratio and to output a driving pulse; a switching device driven by the driving pulse; a piezoelectric transformer to output an alternating-current high voltage when receiving an intermittent voltage from the switching device; a comparison device to compare a digital signal corresponding to the piezoelectric transformer output voltage with a target voltage and to output a comparison result; a controller to control the first frequency-division ratio based on the comparison result; a first holding device to hold the controlled first frequency-division ratio; a first computing device to determine the second frequency-division ratio by performing computation using a first correction value and the first frequency-division ratio held by the first holding device; and a second holding device to hold the second frequency-division ratio determined by the first computing device.

Abstract: A power supply with a digital control circuit generates an output voltage by driving a piezoelectric transducer with an alternating current voltage at a digitally controlled driving frequency. To skip over a spurious frequency, the driving frequency is switched between a first range above the spurious frequency and a second range below the spurious frequency. Within the first and second ranges, the driving frequency is varied in directions that make the output voltage track a target voltage. If the driving frequency arrives at the lower limit of the first range, it jumps to a switchover frequency in the second range. The first range can be used to generate a comparatively low output voltage, and the second range to generate a comparatively high output voltage.

Abstract: A piezoelectric transducer driver configured to drive a piezoelectric transducer for converting an inputted alternating-current voltage, includes: a drive circuit configured to generate the alternating-current voltage to be inputted into the piezoelectric transducer; a frequency controller configured to control a frequency of the alternating-current voltage as a drive frequency to be applied to the piezoelectric transducer; and a pulse generation circuit configured to generate a drive pulse having a switching frequency corresponding to the drive frequency, and to output the drive pulse to the drive circuit. The drive circuit includes a switching element configured to generate the alternating-current voltage by executing a switching operation corresponding to a pulse width of the drive pulse, and the pulse generation circuit changes the pulse width depending on the switching frequency.

Abstract: A power supply apparatus includes an arithmetic unit configured to successively update a N-bit division ratio at every step whose processing timing is managed by a timer, by adding or subtracting of preset data read from a data memory to or from the N-bit division ratio in accordance with a comparative output. An arithmetic unit performs an arithmetic operation to make a feedback data value approach a target data value by a negative feedback control, the arithmetic operation using, as the preset data, data read from the address specified by data with a predetermined bit width of M (M<N) extracted from the successively updated N-bit division ratio.

Abstract: A power supply device includes a voltage output unit configured to output a DC voltage corresponding to a control signal from a first controller and an output evaluator configured to perform a judgment process of judging whether or not the DC voltage is a voltage corresponding to a set value received from the fist controller, and to output a result of the judgment to the first controller. The output evaluator includes a storage for storing correspondence information which shows a correspondence relationship between the set value and a voltage value of the DC voltage outputted from the voltage output unit. The output evaluator performs the judgment process by outputting the correspondence information to the first controller, and receiving a set value determined on the basis of the correspondence information from the first controller.