JP2004104850A - Power unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform power saving control, based on a control signal transmitted from an electronic apparatus, concerning a power unit. <P>SOLUTION: The power unit 1 is equipped with a primary circuit 12 which forms a DC power source from an AC power source and switches and outputs it, a secondary circuit 13 which forms a desired DC power source from the output of the primary circuit 12 and outputs it to power lines 2 and 3, a power control means 11 which extracts a specified control signal being superposed on the potential of a power potential line 2 and sent from an electronic apparatus 4 and controls the power consumption in the primary circuit 12, based on it, and a superposed signal cut filter 14 which is provided between the power source lines 2 and 3 and the secondary circuit 13 and cuts the control signal. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a power supply device, and more particularly to a power supply device that converts an AC power supply such as a commercial power supply into a DC power supply and supplies the DC power supply to an electronic device.
[0002]
[Prior art]
Electronic devices such as personal computers (PCs), printers, and scanners generally operate on DC power obtained by converting commercial power to DC or operate on batteries charged with the DC power. For this purpose, a power supply device (for example, an AC adapter) that converts an AC power supply such as a commercial power supply into a DC power supply and supplies the DC power to the electronic apparatus is used. For example, a personal computer is used while supplying DC power while a commercial power supply is connected to the personal computer via an AC adapter. At this time, the AC adapter supplies the power consumed by the electronic device, and at the same time, consumes power to convert AC to DC.
[0003]
FIG. 13 shows a conventional power supply device (AC adapter). The power supply device 6 converts an AC power supply into a DC power supply in the primary side circuit 62, performs switching and outputs the output, converts the output into a desired DC power supply in the secondary side circuit 63, and outputs it to two power supply lines. . The primary circuit 62 includes a line filter 621, a primary rectifier circuit 622, an input smoothing circuit 623, and a switching circuit 624. The secondary circuit 63 includes a secondary rectifier circuit 631 and an output smoothing circuit 632. The power supply line connects the electronic device and the power supply device 6 and includes a power supply potential line 2 to which a power supply potential is applied and a ground potential (GND) line 3 to which a ground potential is connected.
[0004]
The power supply device 6 itself monitors the output of the power supply device 6 and performs power saving control. That is, the output (for example, voltage) of the secondary circuit 63 detected by the detection circuit 67 is fed back to the switching control circuit 68, whereby the primary circuit 62 is feedback-controlled. For example, when the voltage value of the secondary circuit 63 detected by the detection circuit 67 is small (that is, the power consumption in the electronic device is small), the switching control circuit 68 reduces the duty ratio of the PWM control with respect to the switching circuit 624. Alternatively, the output is reduced by performing control such as lowering the switching frequency.
[0005]
On the other hand, in order to reduce the number of signal lines for power supply and control signals and to save power, there has been proposed a technique of superimposing a serial signal for performing power supply and communication / control on the same line ( For example, see Patent Document 1).
[0006]
[Patent Document 1]
JP-A-7-140060 (paragraphs 0026 to 0047, FIGS. 3, 8 and 9)
[0007]
[Problems to be solved by the invention]
The problem of energy consumption has been pointed out as one of the environmental problems, and various measures for energy saving have been established as measures against this problem. Electronic devices such as personal computers tend to limit power consumption in a sleep (or standby or suspend) state to 1 W (watt) or less.
[0008]
However, in practice, it is not easy to reduce the power consumption including the power supply 6 to 1 W or less in an electronic device in which a commercial power supply is connected via the power supply 6. That is, as described above, the power supply device 6 independently performs power saving control, but does not suppress power consumption in the power supply device 6 itself. The power supply device 6 normally consumes power by itself even when an electronic device such as a personal computer is not operating (light load). For this reason, when the power consumption in the power supply device 6 is considered to be power loss, the power consumption efficiency at the time of light load becomes extremely poor.
[0009]
On the other hand, there is no means for notifying the power supply device 6 of the power saving control from an electronic device such as a personal computer. For example, the power supply device 6 is connected to the electronic device only with the power supply potential line 2 and the GND line 3 and has no signal line. Therefore, conventionally, it has not been possible to perform power saving control of the power supply device 6 in accordance with the power saving mode (for example, sleep, standby, or suspend state) of an electronic device such as a personal computer. Further, the power supply device 6 does not itself have a switch (hereinafter, an AC switch) for manually shutting off the AC power supply from the outside. Therefore, it has been extremely difficult to realize ultra-low power consumption comparable to that when the power supply is completely shut down in the electronic device.
[0010]
An object of the present invention is to provide a power supply device capable of performing power saving control based on a control signal transmitted from an electronic device.
[0011]
[Means for Solving the Problems]
A power supply device of the present invention is a power supply device for supplying a DC power supply formed from an AC power supply (for example, a commercial power supply) to an electronic device via a power supply line including a power supply potential line and a reference potential line. A primary side circuit that forms a DC power supply from the switching circuit and outputs the same, a secondary circuit that forms a desired DC power supply from the output of the primary side circuit and outputs the power supply line, and a power supply potential line from the electronic device. A power control means for extracting a predetermined control signal superimposed on a potential (for example, 5 V) and suppressing power consumption in the primary circuit based on the extracted control signal; A superposed signal cut filter for cutting a control signal superimposed on the potential of the power supply potential line.
[0012]
According to the power supply device of the present invention, the control signal is transmitted by superimposing it on the potential of the power supply potential line, thereby transmitting the control signal from the electronic device such as a personal computer to the power supply device without providing a signal line. It can be notified that the apparatus is in a power saving mode (for example, a standby, sleep, or suspend state). Therefore, the power consumption of the power supply device itself can be suppressed without providing an AC switch in the power supply device, and, for example, ultra-low power consumption equivalent to the case where the AC power supply is cut off can be realized. As a result, in an electronic device in which a commercial power supply is connected via a power supply device, power consumption including the power supply device when the electronic device is lightly loaded (for example, in a standby, sleep, suspend, or the like state) is extremely suppressed. As a result, the power consumption efficiency can be improved, and the energy consumption problem as an environmental problem can be addressed.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a configuration diagram of a power supply system, and shows a configuration of a power supply system to which the power supply device of the present invention is applied.
[0014]
The power supply system includes a power supply device 1, a power supply potential line 2, a GND (ground potential) line 3, and an electronic device 4. The power supply device 1 is connected to an AC power supply such as a commercial power supply (not shown) of a general home, and outputs a DC power supply (5 V, 16 V, etc.) formed from the AC power supply to two power supply lines 2 and 3. The DC power supply is supplied to the electronic device 4 via this. The power supply lines 2 and 3 connect the electronic device 4 and the power supply device 1 and include a power supply potential line 2 to which a power supply potential is applied and a GND line 3 to which a ground potential is connected.
[0015]
Examples of the electronic device 4 include a personal computer, a laser printer, a scanner, a router, and a DSU. When the electronic device 4 is a personal computer, the power supply device 1 is a so-called AC adapter, and is used with a commercial power supply connected thereto. When the electronic device 4 is a laser printer or a scanner, the power supply device 1 includes an AC adapter or is built in the electronic device 4.
[0016]
The power supply device 1 includes a power control unit 11, a primary circuit 12, a secondary circuit 13, and a superimposed signal cut filter 14. The primary circuit 12 forms a DC power supply from an AC power supply. The secondary side circuit 13 forms a desired DC power supply from the DC power supply formed by the primary side circuit 12 and outputs it to the power supply lines 2 and 3. The power control unit 11 extracts a control signal transmitted from the electronic device 4 while being superimposed on the potential of the power supply potential line 2, and suppresses power consumption in the primary circuit 12 based on the control signal. The superimposed signal cut filter 14 is provided between the power supply lines 2 and 3 and the secondary circuit 13 and cuts a control signal superimposed on the potential of the power supply potential line 2 (for example, 5 V, 16 V, etc., the same hereinafter). I do.
[0017]
The electronic device 4 includes a control signal forming circuit 41, a load 42, and a superimposed signal cut filter 43. The control signal forming circuit 41 forms a control signal for controlling the power supply device 1 and superimposes the control signal on the potential of the power supply potential line 2 to send out. The load 42 consumes power supplied from the power supply device 1 via the power supply lines 2 and 3. The superposition signal cut filter 43 is provided between the power supply lines 2 and 3 and the load 42, and cuts a control signal superimposed on the potential of the power supply potential line 2.
[0018]
FIG. 2 is a configuration diagram of the power supply device, and shows a configuration of the power supply device 1 of the present invention in the power supply system of FIG.
[0019]
The power control means 11 includes an extraction / control circuit 111 and an input cutoff control circuit 116. The extraction / control circuit 111 extracts a control signal transmitted from the electronic device 4 while being superimposed on the potential of the power supply potential line 2, forms an internal control signal based on the extracted control signal, and sends it to the input cutoff control circuit 116. . The input cutoff control circuit 116 forms an input cutoff control signal for controlling the primary circuit 12 based on the internal control signal, and sends the signal to the primary circuit 12.
[0020]
The primary circuit 12 includes a line filter 121, a primary rectifier circuit 122, an input smoothing circuit 123, and a switching circuit 124. The primary circuit 12 forms a DC power supply from an AC power supply, and switches and outputs the DC power supply. The line filter 121 cuts noise of the AC power supply from the outlet. The primary rectifier circuit 122 rectifies the AC power input through the line filter 121. The input smoothing circuit 123 smoothes the (DC) power rectified by the primary rectifier circuit 122. The switching circuit 124 outputs a rectangular wave obtained by switching the DC power supply under PWM control to the secondary circuit 13 via the transformer T.
[0021]
The secondary circuit 13 includes a secondary rectifier circuit 131 and an output smoothing circuit 132. The secondary circuit 13 forms a desired DC power supply from the output of the primary circuit 12, and supplies two power lines via a superposed signal cut filter 14. Output to 2 and 3. The secondary rectifier circuit 131 rectifies the switching output (PWM output) of the primary circuit 12 input via the transformer T. The output smoothing circuit 132 smoothes the power rectified by the secondary rectifier circuit 131 and outputs the power.
[0022]
Although not particularly shown, the power supply device 1 actually includes the same detection circuit and switching control circuit as shown in FIG. That is, the detection circuit detects the output of the output smoothing circuit 132 between the output smoothing circuit 132 and the superimposed signal cut filter 14. The switching control circuit performs, for example, PWM control of the switching circuit 124 based on the detection result of the detection circuit.
[0023]
1 and 2, the load 42 of the electronic device 4 transmits a state signal indicating its own power consumption state to the control signal forming circuit 41. For example, the electronic device 4 often includes a CPU (Central Processing Unit) as its load 42. Therefore, the CPU transmits a state signal indicating its operation mode, that is, the depth of the sleep mode. Alternatively, the CPU transmits a state signal indicating hardware operation such as a switch operation or a keyboard operation on the electronic device 4 from the outside when the operation is not performed for a predetermined time or more, or when a predetermined command is not executed for a predetermined time or more. I do. When the load 42 does not include a CPU, a state signal is formed by dedicated hardware in the electronic device 4.
[0024]
The control signal forming circuit 41 forms a control signal based on the state signal received from the load 42, superimposes the control signal on the potential of the power supply potential line 2, and transmits the control signal to the power supply device 1. Therefore, the control signal is transmitted in the electronic device 4 based on, for example, a case where a predetermined hardware operation is performed or a case where the program enters a predetermined execution state. The control signal basically consists of a pulse train as shown in FIG. That is, the pulse train superimposed on the potential of the power supply potential line 2 is, for example, a pulse having a peak (amplitude) of +1.0 V with respect to the potential of the power supply potential line 2 (in this example, +5.0 V as an example). Consists of signals. When this is extracted in the extraction / control circuit 111, a pulse signal having an amplitude of +1.0 V is obtained. The frequency is determined in advance and is, for example, several tens KHz to several hundred KHz.
[0025]
Actually, the pulse train of the control signal is, for example, a pulse train as shown in FIG. That is, the transmission of the control signal is notified by the continuation of four (4 bits) pulses (period A), the period corresponding to the next four pulses is set as the control signal transmission period (period B), and the next The transmission end of the control signal is notified by the continuation of four pulses (period C). In the period B, regarding the four pulse positions, assuming that there are pulses at the first and third positions as shown by solid lines and that there are no pulses at the second and fourth positions as shown by dotted lines, 4 The bit control signal “1010” is extracted. Therefore, 2 ⁴ = 16 control signals can be formed. Thus, for example, each of the 16 control signals can be made to correspond to a power consumption state of the load 42 (a state signal indicating), for example, a state signal indicating the depth of the sleep mode of the CPU. The control signal to be superimposed may be transmitted by, for example, pulse code modulation, pulse width modulation, pulse frequency modulation, or pulse phase modulation.
[0026]
The control signal composed of such a pulse train is cut by the superposed signal cut filters 14 and 43 composed of a circuit (LC filter) as shown in FIG. Thus, the power output characteristics of the power supply device 1 are not affected, and the fluctuation of the power supply level supplied to the electronic device 4 can be prevented.
[0027]
The extraction / control circuit 111 extracts a control signal (the lower signal in FIG. 3) from the electronic device 4 superimposed on the power supply potential line 2 and decodes the control signal, thereby generating an internal control signal based on the extracted control signal. And sends it to the input cutoff control circuit 116. In this example, for example, when the power consumption of the load 42 is the lowest power consumption, an internal control signal indicating this is output.
[0028]
The input cutoff control circuit 116 controls the line filter 121 or the primary rectifier circuit 122 based on the received internal control signal. That is, to control the line filter 121 or the primary rectifier circuit 122, a first or second input cutoff control signal is formed.
[0029]
For example, a first input cutoff control signal is formed and input to the line filter 121. In response, in the line filter 121 shown in FIG. 6, the switch SW1 inserted in series (according to the present invention) with the resistor R (having a high resistance value) connected in parallel with the capacitor C for removing noise is turned off. And Thereby, the leak current in the resistor R of the line filter 121 can be cut off, and the power consumption can be reduced to achieve a state of ultra-low power consumption. Note that the resistor R is for discharging the charge remaining in the capacitor C when the outlet is disconnected.
[0030]
Also, a second input cutoff control signal is formed and input to the primary rectifier circuit 122. In response, as shown in FIG. 7, the power supply line (one or both) of the input side (between the line filter 121 and the primary rectifier circuit 122) of the primary rectifier circuit 122 is inserted in series (according to the present invention). The switch SW2 is turned off. Thereby, the connection between the commercial power supply and the primary rectifier circuit 122 is cut off, the power consumption after the primary rectifier circuit 122 is eliminated, and the power consumption can be reduced to achieve a state of ultra-low power consumption.
[0031]
As described above, the input cutoff control circuit 116 may alternatively control the line filter 121 or the primary rectifier circuit 122 by the first or second input cutoff control signal, and may be controlled by the first and second input cutoff control signals. The line filter 121 and the primary rectifier circuit 122 may be controlled. For example, when the power consumption of the load 42 is the least, the first and second input cutoff control signals are formed, and when the power consumption of the load 42 is the second smallest, the first or second input cutoff control signal is formed. You may make it. When the power consumption of the load 42 is the least, the first and second input cutoff control signals are formed. When the power consumption of the load 42 is the second smallest, only the second input cutoff control signal is formed. When the power consumption of the load 42 is the third lowest, only the first input cutoff control signal may be formed. When the first and second input cutoff control signals are formed to control the line filter 121 and the primary rectifier circuit 122, the power consumption of the power supply device 1 can be substantially the same as when the power supply device is unplugged. .
[0032]
FIG. 8 is a power consumption control processing flow in which the power supply device 1 in FIGS. 1 and 2 is the AC adapter 1 and the electronic device 4 is the laser printer 4, and the control signal has a predetermined program. 7 shows a power consumption control process when transmission is performed based on the execution state.
[0033]
When the power switch is turned on, the laser printer 4 is in a state of waiting for a print command (print signal) (step S1). In this state, the roller of the laser printer 4 is preheating the roller by the heater, and the power consumption is considerably increased. Therefore, in this case, the laser printer 4 does not transmit a control signal, and the AC adapter 1 does not perform low power consumption control based on the control signal. However, the AC adapter 1 performs PWM control of the switching circuit 124 by the detection circuit and the switching control circuit.
[0034]
Next, the laser printer 4 determines whether or not a print command has not been input from a personal computer (not shown) even after a predetermined time has elapsed (step S2). If no input is made after a lapse of a predetermined time, that is, if the control program (OS) of the laser printer 4 is in a waiting state for a predetermined time or more, the laser printer 4 turns off the residual heat of the rollers, and outputs a signal other than a print command receiving circuit. Is also turned off, and a control signal indicating a standby state (a state in which power consumption is the lowest) is transmitted to the AC adapter 1, and thereafter, the apparatus enters a print command waiting state (step S3). According to this control signal, the AC adapter 1 performs ultra-low power consumption control. That is, for example, the first and second input cutoff control signals are formed to cut off the leak current in the resistor R of the line filter 121, cut off the connection between the commercial power supply and the primary rectifier circuit 122, and turn on the primary rectifier circuit 122 and thereafter ( The power consumption of the switching circuit 124 (including the switching circuit 124) is eliminated, and an ultra-low power consumption state is achieved.
[0035]
Thereafter, when the laser printer 4 receives the print command, the laser printer 4 transmits a control signal indicating the release of the standby state (that is, indicates the normal state) to the AC adapter 1, and thereafter, a circuit other than the circuit for receiving the print command is transmitted. The circuit operation is restored, the rollers are warmed up, and printing is started when the temperature reaches or exceeds a predetermined temperature (step S4). In response to this control signal, AC adapter 1 returns to the normal state. That is, for example, the formation of the first and second input cutoff control signals is stopped, and the switch SW1 of the line filter 121 and the switch SW2 of the primary rectifier circuit 122 are turned on, so that a normal power consumption state is set. In addition, since the operation of the primary rectifier circuit 122 and thereafter is performed, the PWM control of the switching circuit 124 by the detection circuit and the switching control circuit is restarted.
[0036]
In step S2, if the print command has not been input even after the predetermined time has elapsed (that is, the predetermined time has not elapsed), the laser printer 4 immediately starts printing upon receiving the print command (step S5). ).
[0037]
The power consumption of the laser printer 4 is maximized by the printing process in step S4 or S5 (step S6). At this time, the AC adapter 1 supplies power according to the power consumption under the PWM control of the switching circuit 124 described above. Thereafter, when printing is completed (Step S7), the laser printer 4 repeats Step S1 and subsequent steps.
[0038]
The control signal from the electronic device 4 is transmitted in step S3 (or step S13 in FIG. 9). The control signal is transmitted immediately after the power-on of the electronic device 4 as a trigger. Is also good. Alternatively, it may be transmitted after a predetermined time has elapsed after the power is turned on. Further, it may be possible to select whether to send the data in step S3 or the like or to use the power supply as a trigger.
[0039]
In this case, a personal computer that sends a print command to the laser printer 4 is also one of the electronic devices 4. The personal computer 4 includes a power supply device (AC adapter) 1 for the personal computer 4. The power consumption of the AC adapter 1 is also controlled according to the present invention.
[0040]
FIG. 9 is a power consumption control processing flow in which the power supply device 1 in FIGS. 1 and 2 is the AC adapter 1 and the electronic device 4 is the laser printer 4, and the control signal is a predetermined hardware. The power consumption control process in the laser printer 4 when sending out based on the operation (in this example, pressing down a key on the keyboard) is shown.
[0041]
As in step S1, the laser printer 4 is in a state of waiting for a print command when the power switch is turned on (step S11). As described above, the laser printer 4 is preheating the roller by the heater, the laser printer 4 does not send out the control signal, the AC adapter 1 does not perform the low power consumption control based on the control signal, and the switching circuit 124 PWM control is performed.
[0042]
Next, the laser printer 4 determines whether a predetermined key (for example, F1 key) of a keyboard (not shown) of the personal computer has been pressed (step S12). When the predetermined key is depressed, the personal computer enters an interrupt processing mode for forcibly controlling the low power consumption of the laser printer 4, and notifies the laser printer 4 of the forced start of the low power consumption control. . Thereby, when a predetermined key is pressed down, that is, when a predetermined hardware operation is performed, the laser printer 4 receives the notification and turns off the residual heat of the roller as in step S3. Circuits other than the print command receiving circuit are also turned off, and a control signal indicating a standby state is transmitted to the AC adapter 1, and thereafter, the printer enters a print command waiting state (step S13). In response to this control signal, the AC adapter 1 forms the first and second input cutoff control signals and performs ultra-low power consumption control as described above.
[0043]
Thereafter, similarly to step S4, when receiving the print command, the laser printer 4 transmits a control signal indicating the release of the standby state to the AC adapter 1, and returns the circuit operation of the circuits other than the print command receiving circuit. Then, the rollers are warmed up and printing is started when the temperature reaches or exceeds a predetermined temperature (step S14). In response to this control signal, the AC adapter 1 stops forming the first and second input cutoff control signals, returns to the normal state, and resumes the PWM control of the switching circuit 124, as described above.
[0044]
If the predetermined key of the keyboard is not depressed in step S12 (that is, the predetermined hardware operation is not performed), the laser printer 4 starts printing immediately upon receiving the print command as in step S5. (Step S15).
[0045]
As in step S6, the power consumption of the laser printer 4 is maximized by the printing process in step S14 or S15 (step S16). At this time, the AC adapter 1 supplies power according to the power consumption by the PWM control of the switching circuit 124 as described above. Thereafter, as in step S7, when printing is completed (step S17), the laser printer 4 repeats step S11 and subsequent steps.
[0046]
FIG. 10 is a configuration diagram of a power supply device, and shows a configuration of another power supply device 1 of the present invention in the power supply system of FIG.
[0047]
The power supply device 1 of this example is obtained by adding a control circuit 115, a detection circuit 117, and a switching control circuit 118 to the configuration of the power supply device 1 of FIG. The detection circuit 117 and the switching control circuit 118 correspond to the detection circuit 67 and the switching control circuit 68 in FIG. 13, respectively. Therefore, the output (for example, voltage or current) of the secondary circuit 13 detected by the detection circuit 117 is feedback-input to the switching control circuit 124, whereby the primary circuit 12 is feedback-controlled. For example, when the voltage value (or current value) of the secondary circuit 13 detected by the detection circuit 117 is small, the switching control circuit 118 reduces the duty ratio of the PWM control to the switching circuit 124 or reduces the switching frequency. Control such as lowering the output is performed to reduce the output.
[0048]
However, in this example, the output of the detection circuit 117 is input to the control circuit 115. The control signal extracted by the extraction / control circuit 111 is also input to the control circuit 115 (without being decoded). The control circuit 115 generates an internal control signal based on these inputs and transmits the signal to the switching control circuit 118 and the input cutoff control circuit 116.
[0049]
That is, in the range of power consumption that can be handled by increasing or decreasing the duty ratio of the PWM control in the switching circuit 124, the control circuit 115 ignores the control signal from the extraction / control circuit 111 and controls the input cutoff control circuit 116 to perform internal control. A signal is not transmitted, and the output from the detection circuit 117 is directly input to the switching control circuit 118 as an internal control signal. In a range of low power consumption such that the duty ratio cannot be further reduced, the control circuit 115 forms a control signal to the switching circuit 124 based on the control signal from the extraction / control circuit 111, and generates a pulse output from the control signal. Thin out. For example, the number of times of thinning out the pulse is increased in accordance with the degree to which the power consumption of the load 42 indicated by the control signal is small. Further, in a range of ultra-low power consumption in which the number of times of decimating the pulse is equal to or more than a predetermined number, the control circuit 115 determines the first and / or second signals based on the control signal from the extraction / control circuit 111. An input cutoff control signal is formed and input to the input cutoff control circuit. At this time, the switching circuit 124 is not operated (switched), for example.
[0050]
Thus, for example, when the electronic device 4 is in the low power consumption mode, the switching circuit 124 is controlled using the switching control circuit 118, and when the electronic device 4 is in the ultra-low power consumption mode, the input cutoff control circuit 116 is used. The line filter 121 and the primary rectifier circuit 122 can be controlled. Thereby, power saving control in the power supply device 1 according to each stage of the power saving mode of the electronic device 4 can be performed.
[0051]
FIG. 11 is a configuration diagram of a power supply device, and shows a configuration of another power supply device 1 of the present invention in the power supply system of FIG.
[0052]
The power supply device 1 of this example is obtained by providing a 4-bit CPU 111C in the configuration of the power supply device 1 of FIG. That is, the extraction / control means 111A includes an extraction / superposition circuit 111B and a power consumption control processing means 111C. The extraction / superposition circuit 111B extracts a predetermined control signal. The power consumption control processing unit 111C processes the extracted predetermined control signal. That is, processing for suppressing power consumption in the primary circuit 12 is performed based on a predetermined control signal. The power consumption control processing means 111C includes the above-described CPU 111C and a power consumption control processing program (not shown) executed thereon. The power consumption control processing program is stored in, for example, a memory (not shown) included in the CPU 111C.
[0053]
The extraction / superposition circuit 111B extracts a control signal and inputs this to the power consumption control processing means 111C. The power consumption control processing means 111C forms an internal control signal based on the control signal and sends it to the control circuit 115, similarly to the extraction / control circuit 111. The power consumption control processing unit 111C that has received the control signal outputs an instruction signal to the extraction / superposition circuit 111B, and notifies the electronic device 4 of the control state information in the power supply device 1, that is, the fact that the power supply device 1 has shifted to the ultra-low power consumption mode. Let me reply. That is, the extraction / superposition circuit 111B forms a response signal indicating the transition based on the instruction signal, and superimposes the response signal on the power supply potential line 2 in the same manner as the control signal formation circuit 41 of the electronic device 4. Send out. The control signal forming circuit 41 extracts the response signal transmitted in a manner superimposed on the potential of the power supply potential line 2 in the same manner as the extraction / control circuit 111. Therefore, bidirectional communication can be performed between the power supply device 1 and the electronic device 4. For example, the response signal is an inverted signal of the control signal. Thus, in the case of the example of FIG. 4, eight control signals and eight corresponding response signals can be superimposed on the power supply potential line 2.
[0054]
FIG. 12 is a flowchart of the power consumption control processing, and shows the power consumption control processing in the power supply system including the power supply device 1 of FIG. The power supply 1 is an AC adapter 1 and the electronic device 4 is a laser printer 4.
[0055]
The laser printer 4 turns off the residual heat of the roller, turns off the circuit operation of the circuits other than the interface circuit by executing step S3 in FIG. 8 or step S13 in FIG. It transmits (step S21). The power supply device 1 that has received the control signal forms the first and / or second input cutoff control signal based on the control signal and controls the line filter 121 and / or the primary rectifier circuit 122, as described above. As a result, the mode shifts to the ultra-low power consumption control mode, and if there is no problem in the shift in the power supply device 1 (if the shift can be performed without failure), the laser printer 4 sends a response signal indicating that the mode has shifted to the ultra-low power consumption control mode. A reply is sent (step S22). The laser printer 4 having received the response signal transmits that the power consumption is 1 W or less to a personal computer (not shown) based on the response signal received from the power supply device 1 (step S23). The personal computer that has received this displays an icon indicating that the laser printer 4 is in a standby state of 1 W or less (step S24).
[0056]
【The invention's effect】
As described above, according to the present invention, in the power supply device, the control signal is transmitted from the electronic device to the power supply device without providing the signal line by transmitting the control signal superimposed on the potential of the power supply potential line. To notify that the mode is the power saving mode, the power consumption of the power supply device itself is suppressed without providing an AC switch in the power supply device, for example, the same level as when the AC power supply is shut off. Very low power consumption can be realized. Thus, in an electronic device in which a commercial power supply is connected via the power supply device, power consumption including the power supply device when the electronic device has a light load can be reduced to 1 W or less.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a power supply system, showing a configuration of a power supply system to which a power supply device of the present invention is applied.
FIG. 2 is a configuration diagram of a power supply device, showing a configuration of the power supply device of the present invention in the power supply system of FIG. 1;
FIG. 3 is an explanatory diagram of a control signal.
FIG. 4 is an explanatory diagram of a control signal.
FIG. 5 is a configuration diagram of a superposition signal cut filter.
FIG. 6 is a configuration diagram of a line filter.
FIG. 7 is an explanatory diagram of a primary rectifier circuit.
FIG. 8 is a power consumption control processing flow, showing the power consumption control processing when the power supply device is an AC adapter and the electronic device is a laser printer.
FIG. 9 is a power consumption control processing flow, showing the power consumption control processing when the power supply device is an AC adapter and the electronic device is a laser printer.
10 is a configuration diagram of a power supply device, and shows a configuration of another power supply device 1 of the present invention in the power supply system of FIG.
11 is a configuration diagram of a power supply device, and shows a configuration of another power supply device 1 of the present invention in the power supply system of FIG. 1;
FIG. 12 is a power consumption control processing flow, showing power consumption control processing in a power supply system including the power supply device of FIG. 11;
FIG. 13 is a configuration diagram of a conventional power supply device.
[Explanation of symbols]
1 power supply
2 Power supply potential line
3 GND line
4 Electronic equipment
11 Power control means
12 Primary circuit
13 Secondary circuit
14 Superimposed signal cut filter
41 Control Signal Forming Circuit
42 load
43 Superimposed signal cut filter

Claims (6)

A power supply device that supplies a DC power supply formed from an AC power supply to an electronic device via a power supply line including a power supply potential line and a reference potential line,
A primary side circuit that forms a DC power supply from the AC power supply, and switches and outputs the DC power supply;
A secondary circuit that forms a desired DC power supply from the output of the primary circuit and outputs the power to the power supply line,
A power control unit that extracts a predetermined control signal transmitted from the electronic device while being superimposed on the potential of the power supply potential line, and that controls power consumption in the primary-side circuit based on the extracted control signal.
A power supply device, comprising: a superimposition signal cut filter provided between the power supply line and the secondary circuit, for cutting a control signal superimposed on a potential of the power supply potential line. The primary side circuit includes a capacitor connected between the power supply potential line and the reference potential line, and a filter including a resistor connected in parallel with the capacitor,
Providing a switch in series with the resistor,
The power supply device according to claim 1, wherein the power control unit turns off the switch based on the predetermined control signal. The primary-side circuit includes a primary rectifier circuit that forms the DC power supply by rectifying the AC power supply,
A switch is provided between the AC power supply and the primary rectifier circuit,
The power supply device according to claim 1, wherein the power control unit turns off the switch based on the predetermined control signal. The predetermined control signal is a signal transmitted based on a case where a predetermined hardware operation is performed in the electronic device or a case where a program enters a predetermined execution state. The power supply device according to claim 1. 2. The power supply device according to claim 1, wherein the predetermined control signal is transmitted immediately after power-on of the electronic device. The power supply further includes:
A CPU,
A power consumption control processing program that suppresses power consumption in the primary circuit based on the predetermined control signal,
The power control means includes an extraction circuit for extracting the predetermined control signal, the CPU, and a power consumption control processing program, and includes a power consumption control processing means for processing the extracted predetermined control signal. The power supply device according to claim 1, wherein:

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