Abstract: This invention provides an image forming apparatus which performs sleep control for a shift to the sleep mode for each function and provides a user-friendly operation system, and a method of controlling the same. To accomplish this, the image forming apparatus sets a shift time until a power state of the image forming apparatus shifts to the low-power state after execution of image formation; and performs control to shift the power state of the image forming apparatus to the low-power state, when the shift time is not more than the predetermined time, before an elapse of the shift time after execution of image formation by the printing function, while shifting the power state of the image forming apparatus to the low-power state, in response to an elapse of the shift time after execution of image formation by the copying function.

Abstract: The heating apparatus includes a first detection part which detects whether or not the power supplied to the heat generation member is in an overpower state by detecting a positive phase of a half wave in an alternating voltage of a commercial power supply applied to the first or the second current path of the heat generation member, a second detection part which detects whether the power supplied to the heat generation member is in an overpower state or not by detecting a negative phase of a half wave in an alternating voltage the commercial power supply applied to the first current path or the second current path of the heat generation member, and a control part which controls itself to stop supplying power from the commercial power supply to the heat generation member in a case where an overpower state is detected by the first or second detection part.

Abstract: An image forming apparatus has at least one measurement unit, disposed on a respective power-supply line extending from a first power source to a respective at least one operation module disposed in the image forming apparatus, configured to measure power consumption at the at least one operation module; and a power-saving unit configured to shut down the power supply from the first power source to the at least one operation module to set the image forming apparatus to a power-save mode, wherein the image forming apparatus is configured to shut down power supply to the at least one measurement unit, when the power-saving unit sets the image forming apparatus to the power-save mode.

Abstract: An image forming apparatus includes a first control unit configured to control an image forming unit; a power supply unit configured to supply power from a commercial power source; a switching unit configured to switch a connection state between the power supply unit and the commercial power source from a conduction state to a non-conduction state, or vice versa; a capacitor configured to store therein power used by the switching unit; a second control unit configured to detect a start signal for starting power supply from the power supply unit; and a battery for supplying power to the second control unit. The power supply unit supplies power to the first control unit in the conduction state and stops the power supply in the non-conduction state. When detecting the start signal, the second control unit causes the switching unit to switch the connection state to the conduction state.

Abstract: The power supply device includes a transformer that includes primary, secondary and auxiliary windings; a switching unit that switches current flowing to the primary winding of the transformer; a current detection unit that detects current flowing through the primary winding, and outputs a voltage according to the current; a control unit that controls switching operation of the switching unit, according to the voltage output from the current detection unit; a first voltage detection unit that detects a voltage induced in the auxiliary winding; and a correction unit that corrects the voltage output by the current detection unit to the control unit when the voltage induced in the auxiliary winding and detected by the first voltage detection unit is higher than a first predetermined value. This configuration can reduce start-up power consumption while suppressing the vibration noise of the transformer.

Abstract: The power supply apparatus includes a transformer having a primary side and a secondary side insulated from each other, a switch element for switching current flowing in the primary side of the transformer, a control part configured to control an operation of the switch element, and two feedback parts configured to detect an output voltage from the transformer so as to output, to the control part, a detection signal in accordance with the output voltage for feedback to the primary side of the transformer.

Abstract: An image forming apparatus includes a printing engine to form an image on a printing medium through printing processes, an engine frame to support the printing engine having a driving system to drive the printing engine, a high voltage power supply provided in a surface of the engine frame to apply a high voltage to at least one of units performing the printing processes, a main board provided in a surface of the engine frame adjacent to the surface having the high voltage power supply, and having a system engine controller to control the printing engine and a video controller to control a video signal, first and second main connectors respectively provided at lateral sides of the high voltage power supply and the main board adjacent to each other, and a connection control line to connect the first and second main connectors.

Abstract: A power supply system includes: capacitors connected to an alternating current power supply; a rectification circuit connected to the capacitors and rectifying an alternating current voltage applied to the capacitors; a signal generation circuit connected to an output line of the rectification circuit and configured to generate a detection signal corresponding to a zero cross point of an alternating current output; an electricity storage unit connected to the output line of the rectification circuit; a backflow regulation element provided on the output line of the rectification circuit and configured to regulate backflow of current; a current limit element configured to limit current flowing from the output line of the rectification circuit towards the electricity storage unit, and a control unit that is connected to the output line of the rectification circuit, and is configured to detect a zero cross point of the alternating current output.

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 power supply device includes a first switch section that can disconnect a 24-V power supply from a commercial alternating-current (AC) power supply and that operates with the voltage of 3.3 V, and a second switch section that can disconnect a voltage detection circuit from the commercial AC power supply and that operates with the voltage of 3.3 V. When a power saving mode is on, the 24-V power supply and the voltage detection circuit are disconnected from the commercial AC power supply by using the first and second switch sections, whereby the power supply device can be used in areas where different supply voltages are used, and at the same time reduction in power consumption in the power saving mode is achieved.

Abstract: An image forming apparatus having; image supporting members provided for a plurality of colors; chargers to be impressed with charging biases to charge the respective image supporting members; developing devices to be impressed with developing biases to develop latent images formed on the image supporting members; a charging bias power supply, including high-voltage DC power supply circuits and an AC power supply circuit, for applying the charging biases, which are generated by superposition of direct-current voltages and an alternate-current voltage, to the chargers; and a control circuit that performs stop processing to stop applications of the charging biases and the developing biases.

Abstract: An image-forming apparatus includes: a fixing unit; a load; a power source circuit section; a fixation electrical current detecting body; a total electrical current detecting body; a storage unit; and a fixation control unit. The fixing unit fixes a toner image using a heat generator. The power source circuit section supplies electric power to the load. The storage unit stores electrical current change amount data establishing an amount of change in the magnitude of the total electrical current relative to an amount of change in a phase for each value of the power factor of the fixing unit. The fixation control unit finds the power factor of the fixing unit, and alters the phase at which the heat generator starts to be energized on the basis of the power factor thus found and the electrical current change amount data, so that the total electrical current value approaches a target value.

Abstract: According to an aspect of the present invention, a power supply device includes: a DC power supply that outputs a DC voltage; an AC power supply that outputs any one of the DC voltage and a superimposed voltage being the DC voltage with an AC voltage superimposed thereon; and a bypass capacitor that charges a part of a voltage that is output from the AC power supply. The DC power supply starts outputting the DC voltage in a constant voltage mode and, when a predetermined condition is satisfied, switches from the constant voltage mode to a constant current mode to output the DC voltage in the constant current mode.

Abstract: The present invention provides an image processing apparatus for performing a process of transiting to a power-off state or sleep state in accordance with the connected state of an interface, a control method thereof, and a storage medium. To accomplish this, if a condition for changing the power state of this image processing apparatus is satisfied, the image processing apparatus confirms an interface which is able to communicate with an external apparatus, and determines whether the image processing apparatus can transit to the sleep state based on the confirmation result. If it is determined that the image processing apparatus transits to the sleep state, the image processing apparatus is transited to the sleep state. If it is determined that the image processing apparatus does not transit to the sleep state, the image processing apparatus is turned off.

Abstract: A power supply circuit includes a voltage regulator to which a first high voltage is supplied, to operate at constant voltage and regulate the supplied first high voltage, and a first rectifier circuit to which the first high voltage is supplied, connected in parallel to the voltage regulator, to rectify the supplied first high voltage for output as a first DC voltage. When the first high voltage is a pseudo-alternating-current (AC) voltage consisting of two types of high voltages that alternate, the voltage regulator regulates each of the two different types of the voltages to output a desired pseudo-AC voltage.

Abstract: An electronic device includes a first voltage output part configured to output a first voltage, a second voltage output part configured to output a second voltage, a first controller configured to receive the first voltage supplied from the first voltage output part, a second controller configured to receive the first voltage supplied from the first voltage output part, and a third controller configured to receive the second voltage supplied from the second voltage output part. The first controller stops the supply of the first voltage to the second controller by the first voltage output part after the supply of the second voltage to the third controller by the second voltage output part has been stopped.

Abstract: A apparatus (cloud) that transmits job data to a terminal (MFP), which is capable of causing the terminal to execute a job without wastefully consuming electric power immediately after completion of job data processing. The cloud generates job data, and determines whether or not the MFP is in a first state in which the MFP cannot process the job data immediately. Further, the cloud stores information on a time period required for the MFP to shift from the first state to a second state in which the MFP can process the job data immediately. The cloud transmits an instruction for causing the MFP to shift from the first state to the second state, to the MFP, based on a time period required for generating the job data, and the time period indicated by the information.

Abstract: An image forming apparatus executes the steps of: calculating an end time of the job of which execution is instructed, and determining if the end time of the job is before the start time of power outage; specifying, if it is determined that the end time of the job is not before the start time of power outage, a part of processing of the job that can be completed before the start time of power outage; starting the job, if it is determined that the end time of the job is before the start time of power outage; and starting the part of processing of the job if it is determined that the end time of the job is not before the start time of power outage. Thus, abnormal termination of an active job due to power outage can be prevented.

Abstract: An image transfer device includes an image bearing member, a pair of opposed transfer members, a media separator, and an electrical bias applicator. The image bearing member defines an image bearing surface on which a toner image is created. The pair of opposed transfer members is disposed opposite each other via the image bearing member to form a transfer nip therebetween through which a recording medium is passed. One of the transfer members defines a first electrode to which a first electrical bias is applied. The media separator defines a second electrode downstream from the transfer nip to which a second electrical bias is applied. The electrical bias applicator includes a power supply connectable with each of the first and second electrodes to supply the first electrical bias to the first electrode and the second electrical bias to the second electrode.

Abstract: An electric power control unit alternately repeats a first electric power control period and a second electric power control period when a low electric power mode is set by a mode setting unit. When a sleep mode is set by the mode setting unit, a second electric power control is executed.

Abstract: A current-supply control unit for controlling current supply to a heating element includes a voltage detector and a heating element control unit. The voltage detector detects voltage at both ends of the heating element. The heating element control unit controls a duty cycle of current supply for the heating element based on the voltages detected by the voltage detector when current is supplied to the heating element.

Abstract: Described herein is a transfer device that transfers a visualized image formed on an image carrier onto a recording medium. The transfer device includes an image carrier that carries a toner image, a contacting member that contacts the image carrier via a recording medium and a power source that outputs a transfer bias to transfer the toner image from the image carrier onto the recording medium at a transfer nip formed between the image carrier and the contacting member. The transfer bias has a direct current component and an alternating current (AC) component superimposed on the direct current component. The transfer device also includes a controller that controls the power source such that the controller controls a level of the direct current component output from the power source by a constant current control.

Abstract: An image forming apparatus for controlling power supply is provided. An image forming apparatus includes at least one cover unit to be mounted in the image forming apparatus, at least one replaceable unit to participate in an image forming operation of the image forming apparatus, a sensing unit to sense whether the at least one cover unit is opened or closed, and a main board unit to cut off the power supply to the at least one replaceable unit for a predetermined period of time when the at least one cover unit is opened or closed. Accordingly, stable operation is enabled.

Abstract: The heating apparatus includes a first detection part which detects whether or not the power supplied to the heat generation member is in an overpower state by detecting a positive phase of a half wave in an alternating voltage of a commercial power supply applied to the first or the second current path of the heat generation member, a second detection part which detects whether the power supplied to the heat generation member is in an overpower state or not by detecting a negative phase of a half wave in an alternating voltage the commercial power supply applied to the first current path or the second current path of the heat generation member, and a control part which controls itself to stop supplying power from the commercial power supply to the heat generation member in a case where an overpower state is detected by the first or second detection part.

Abstract: A power supply system includes: a switching power supply for converting an AC voltage from an AC power supply into a DC voltage; a latching relay provided on an AC input line for switching a connection state of the switching power supply with the AC power supply in response to a relay drive signal; a control device for generating a relay control signal; a relay drive circuit for generating the relay drive signal in response to an input of the relay control signal and driving the latching relay by the relay drive signal; a battery for supplying electric power to the control device and the relay drive circuit when they are connected; and a switch for switching the connection state of the battery with respect to the control device and the relay drive circuit.

Abstract: An image forming apparatus that forms a color image by overlaying toner images formed on respective first, second, and third photoreceptors, comprising: first, second, and third voltage-applied members respectively facing the first, second, and third photoreceptors; a first AC power supply generating first AC voltage, and superimposing the first AC voltage on first DC voltage to generate first voltage for causing a first electric field between the first voltage-applied member and the first photoreceptor; a second AC power supply generating second AC voltage, and superimposing the second AC voltage on second DC voltage to generate second voltage for causing a second electric field between the second voltage-applied member and the second photoreceptor; and a composite circuit superimposing a composite of the first voltage and the second voltage on third DC voltage, to generate third voltage for causing a third electric field between the third voltage-applied member and the third photoreceptor.

Abstract: A boosting circuit includes a switch element, a first coil, a second coil, and a capacitor. The switch element generates a first alternating current voltage having a first frequency from a direct current voltage. The first coil generates a magnetic field around the first coil with a flow of the first alternating current voltage having the first frequency in the first coil. The first coil also induces an eddy current in the object with the magnetic field to inductively heat the object. The second coil is cumulatively connected to the first coil. The capacitor is connected to the first coil and the second coil in a parallel manner.

Abstract: A fixing device includes a fixing unit, a power controller, a pressure applying unit, and a timing controller. The fixing unit fixes toner onto a recording medium transported in a determined transport direction, by using heat generated by a heat generator. The power controller controls supply of power for heating the fixing unit. The pressure applying unit applies pressure to the recording medium in a nip part formed between the pressure applying unit and the fixing unit. The timing controller controls the power controller to start supply of the power at a time which is a determined time period prior to an arrival time at which a leading edge of the recording medium in the transport direction arrives at the nip part.

Abstract: An image forming apparatus includes a transfer unit configured to transfer a toner image onto a recording medium; a power supply unit configured to output one of an alternating-current-based voltage including at least an alternating-current voltage and a direct-current voltage to the transfer unit; and a power supply control unit configured to cause the power supply unit to start switching to the alternating-current-based voltage a first time after the power supply unit stops outputting the direct-current voltage in the case that output of the power supply unit is switched to the alternating-current-based voltage, and cause the power supply unit to start switching to the direct-current voltage a second time after the power supply unit stops outputting the alternating-current-based voltage in the case that output of the power supply unit is switched to the direct-current voltage. The second time is longer than the first time.

Abstract: A fixing device includes a rotatable fixing member that heats a surface of a recording medium on which an unfixed image is carried, a rotatable pressing member that makes pressure-contact with the fixing member to form a nip portion therebetween, a heat source that heats the fixing member, a temperature detecting unit that detects a temperature of the fixing member, and a temperature control unit that controls turning-on/off the heat source in accordance with a predetermined duty for a predetermined control cycle in a turning-on/off cycle, based on input temperature information. The temperature control unit, during execution of a continuous image-forming job for continuously forming images on a plurality of recording media, sets the control cycle and a space between the recording media to be conveyed to the nip so that a number of turn-ons of the heat source is the same for all the recording media.

Abstract: An image forming apparatus is provided with a high-voltage substrate, a motor and a DC power source. The high-voltage substrate has a developing positive bias circuit and a developing reverse bias circuit which are connected to each other in parallel, in which the developing positive bias voltage is combined with developing reverse bias voltage to generate developing bias voltage. The high-voltage substrate includes a interruption switch for interrupting a reverse current from the motor to the developing reverse bias circuit in a case where an interlock switch is turned off at the time of emergency stop, in which, when the reverse current is interrupted by the interruption switch, electric power that is accumulated in the capacitor is supplied to the developing positive bias circuit to apply the developing positive bias voltage as the developing bias voltage to the developing roller for a given length of time.

Abstract: An image forming apparatus is disclosed that includes a power storage unit. The power storage unit includes a constant voltage generation part configured to generate a constant voltage from a commercial power supply, the constant voltage generation part being connected to an external apparatus operating by consuming power; a voltage increasing circuit configured to increase the constant voltage generated by the constant voltage generation part; a capacitor configured to store an electric charge supplied from the voltage increasing circuit; a circuit control part configured to control charging of the capacitor; and an output part configured to output power stored in the capacitor, the power having a voltage different from the constant voltage.

Abstract: An induction heating device includes the following elements: a resonance circuit; a power factor improvement circuit for boosting rectified output, supplying the output to an inverter, and improving the power factor of a commercial alternating current; and a load material detector for detecting the material of the load. The inverter includes switching elements forming a full-bridge circuit. The drive frequency of the switching elements is switched between a frequency substantially equal to a resonance frequency of the resonance circuit and a frequency substantially 1/n time (n being an integer equal to or larger than two) thereof, according to a detection result of the load material.

Abstract: A method for delivering electric power to power consumers of a printing technology machine, which permits high availability of the machine with low idling losses, includes taking start-up time periods of the power consumers into account when switching over the power delivery to power consumers of a printing machine.

Abstract: A power supply system includes a switching power supply for outputting a predetermined DC voltage by converting an AC voltage from an AC power supply, a latching relay provided on an AC input line for switching a connection state of the switching power supply and the AC power supply in response to a relay drive signal, a storage circuit storing electricity from the switching power supply, a control device for receiving electric power from the storage circuit in a disconnection state, and a relay drive circuit for generating the relay drive signal and outputting it to the latching relay. The control device determines whether an amount of charge of the storage circuit has decreased to a predetermined amount of charge in the disconnection state, and generates and outputs the relay control signal to the relay drive circuit.

Abstract: A power source apparatus includes a transformer configured to output a voltage, a feedback unit configured to output a feedback signal based on the voltage output from the transformer, and a driving unit configured to drive the transformer according to a setting signal for setting the output voltage and the feedback signal. Whichever of a voltage of positive polarity and a voltage of negative polarity is output, the feedback unit controls the voltage output according to a value of a difference between the output voltage and a threshold value.

Abstract: An image processing apparatus includes an image-processing designating unit that allows a user to designate predetermined image processing to be applied to image data for generating a preview image that represents a state of an output image before image output; a preview-image generating unit that generates a preview image in accordance with the designated image processing; a preview-image display unit that displays the preview image generated by the preview-image generating unit; and a display-mode switching control unit that, when the preview image is displayed, switches to a display mode with an enhanced viewability relative to a power-saving display state in accordance with a content of the designated image processing.

Abstract: The present invention is directed to an image forming apparatus which can reduce power supply to a first control unit when the image forming apparatus operates in a power saving mode and cause an image forming unit to perform a specific operation without using the first control unit, and a control method thereof.

Abstract: Provided is a power supply apparatus with low power in a standby mode. The apparatus includes a voltage multiplier configured to multiply an input voltage and including a first terminal through which the multiplied voltage is output and a second terminal through which a voltage lower than a voltage of the first terminal is output; a main switch-mode power supply (SMPS) configured to receive the voltage of the first terminal of the voltage multiplier; and a standby SMPS configured to receive a voltage of the second terminal of the voltage multiplier.

Abstract: The power supply includes a transformer, a first switching element for performing a switching operation of turning on and off a voltage input to a primary side of the transformer, a second switching element to be connected to a secondary side of the transformer so as to be turned on and off in accordance with a voltage generated in the secondary side of the transformer, and a control unit for controlling an operation of the first switching element so that an output voltage of the secondary side of the transformer becomes a predetermined voltage. A conductive state period of the second switching element is adjusted to be longer as a frequency of the switching operation of the first switching element is higher.

Abstract: An image processing device includes a detecting unit, a processing unit, a plurality of controllers, a command determination unit, and a load determination unit. The detecting unit is for detecting a command. The processing unit executes a process for the command. The plurality of controllers controls the processing unit and includes a first controller. The command determination unit determines whether or not the command indicates that the process is to be executed by the processing unit under the control of the first controller. The load determination unit determines whether or not a load required for the process is larger than a prescribed threshold value. While the first controller is in a halted state, if the command determination unit makes a negative determination and if the load determination unit makes a positive determination, the first controller is activated and controls the processing unit to execute the process.

Abstract: When an image forming apparatus shifts to a power saving mode, a controller unit further reduces power consumption by switching AC current on/off every predetermined amount of time. When AC current input from a commercial AC power supply is turned off, a DC voltage generating circuit normally can no longer supply a DC voltage, rendering the controller unit unable to operate. Accordingly, the controller unit operates using a charge accumulated in a smoothing capacitor while the AC current is not being supplied. An AC cutting circuit is switched on before a both-end voltage at the smoothing capacitor drops below a lower limit of operation voltage of the DC voltage generating circuit, and the smoothing capacitor is recharged.

Abstract: In a switching power source, an OFF-period of switching is set according to a resonance cycle when a transformer is driven.

Abstract: An image forming apparatus is provided. The image forming apparatus includes an image forming section, an intermediate transfer section, a secondary transfer section, a fixing section, a power source, a voltage detection section, a temperature detection section, and a fixing section control circuit. The fixing section control circuit includes a switching control section, a voltage judgment section, a temperature judgment section, and a preparation control section. When the switching control section switches the current conduction state to the heat source and the driving section from an off conduction state to an on conduction state and the voltage judgment section judges to be less than a threshold voltage, the preparation control section controls the preparation operation of the heating section such that the switching control section continues the on conduction state over a given idle time after the temperature judgment section has judged to be a preset temperature or higher.

Abstract: A rotary developing device that rotates about a rotational axis includes plural developing units, an energized member, a hollow cylindrical unit, a first energizing member, a rotatable unit, a second energizing member, a first conductive member, and a second conductive member. Each developing unit develops a latent image formed on an image holding member into a visible image, and is rotatable about the rotational axis so as to be sequentially movable to a developing position facing the image holding member. The hollow cylindrical unit is arranged along the rotational axis. The rotatable unit is supported rotatably with respect to the hollow cylindrical unit. One end of the first conductive member is connected to the first energizing member supported on an outer periphery of the hollow cylindrical unit. The second conductive member connects the second energizing member supported by the rotatable unit to the energized member supported in a developing unit.

Abstract: An image forming apparatus includes a latent image forming unit that forms a latent image on an image bearing member, a developing unit that develops the latent image to obtain a developer image, and a transfer unit that transfers the developer image to a recording medium. A first supply unit supplies a voltage to a charging unit and the transfer unit, with the first supply unit including a transformer, and a second supply unit supplies a voltage to the transfer unit, with the second supply unit including a transformer and supplying a voltage supplied opposite in polarity to the voltage supplied from the first supply unit. In addition, a detection unit detects current flowing through the transfer unit, and a control unit is configured to control power supply.

Abstract: There is disclosed a power supply control device including a load that executes a predetermined process and operates when power is supplied; a power supply state transition controlling unit that allows at least the load to be transitioned to a power supply state, or a power interruption state; plural detection units that can operate within respective power-consumption ranges, and detects information related to the execution of the load; a power supply control unit for detection unit, which supplies power continuously to a minimum power-consumption type detection unit, and which supplies power to a detection unit having a relatively large power-consumption based on a detection result of a detection unit having a relatively small power-consumption; and a transition time determining unit that is executed when power is supplied with respect to a maximum power-consumption type detection unit, and that determines a transition time by the power supply state transition controlling unit.

Abstract: A power supply system includes: a switching power supply configured to rectify and smooth an AC voltage of an AC power supply to generate a predetermined DC voltage; a low-capacity power supply circuit that generates a zero-cross detection signal corresponding to zero-cross points of the AC power supply based on a rectified current flowing in a smoothing capacitor; and a controller configured to receive the zero-cross detection signal from the signal generating circuit and perform a determining process of determining whether it is possible to perform detection process of the zero-cross points based on a voltage value of the zero-cross detection signal. If the control unit determines that it is possible to perform the detection process of the zero-cross points, the control unit performs a zero-cross point detecting process of detecting the zero-cross points based on the zero-cross detection signal.

Abstract: A switching power source includes: a transformer; a semiconductor switching element that is provided at a primary side of the transformer; a rectifying-and-smoothing circuit that is provided at a secondary side of the transformer; a switching controller configured to perform a switching control to turn on-and-off the semiconductor switching element, wherein the switching controller comprises: a stoppage circuit configured to perform a stoppage process to stop the switching control when a first-level control signal is input, a restart circuit configured to restart the switching control when a second-level control signal different in its level from the first-level control signal, and a limiting circuit configured to limit, at the time of a start-up of the switching power source, a performance of the stoppage process performed by the stoppage circuit until an output voltage of the switching power source increases to a target voltage.

Abstract: A power supply device includes a first switch section that can disconnect a 24-V power supply from a commercial alternating-current (AC) power supply and that operates with the voltage of 3.3 V, and a second switch section that can disconnect a voltage detection circuit from the commercial AC power supply and that operates with the voltage of 3.3 V. When a power saving mode is on, the 24-V power supply and the voltage detection circuit are disconnected from the commercial AC power supply by using the first and second switch sections, whereby the power supply device can be used in areas where different supply voltages are used, and at the same time reduction in power consumption in the power saving mode is achieved.