JP2014155249A - Ac adaptor and power supply determination method for ac adaptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that since when an incompatible AC adaptor is used, abnormal load currents do not necessarily flow, there is possibility that an AC adaptor side overcurrent protection circuit or an electronic equipment side fuse or the like do not operate, and that there is a risk that the AC adaptor is put in an overload state or a risk that the electronic equipment does not normally operate in this case.SOLUTION: An AC adaptor which supplies a power to electronic equipment includes: a transformer; current detection means arranged at the secondary side of the transformer; time measurement means; and determination means for controlling the time measurement means on the basis of currents detected by the current detection means, and for determining the propriety of power supply to the electronic equipment on the basis of the time measured by the time measurement means.

Description

  The present invention relates to an AC adapter and an AC adapter power supply determination method.

  In general, electronic devices such as notebook personal computers, liquid crystal displays, and game machines are configured to operate with power supplied from an AC (Alternating Current) adapter.

  The AC adapter and the electronic device are connected by a detachable connector. The connector on the AC adapter side is called a plug, and the connector on the electronic device side is called a jack. Electric power is supplied by connecting the plug on the AC adapter side to the jack on the electronic device side.

  In a EIAJ (Japan Electronics and Information Technology Association) polarity unified plug, the shape of the connector and the pin arrangement are unified by voltage. However, there are also examples that employ manufacturer-specific connectors.

  Each electronic device employs an AC adapter that conforms to the specifications depending on the power consumption on the electronic device side. Therefore, when the voltage is the same but the rated current is different, the user may use an incompatible AC adapter that is not specified by the manufacturer.

  Patent Document 1 (Japanese Patent Laid-Open No. 2012-055085) is disclosed as a technique for suppressing the use of an incompatible AC adapter that is not specified by a manufacturer.

  This technique detects the signal level including the inherent noise of the AC adapter, and determines whether the AC adapter connected to the electronic device is compatible or not.

  In addition, Patent Document 2 (Japanese Patent Application Laid-Open No. 2012-022533) is disclosed as a technique for stopping power supply immediately after power is turned on.

  This technology provides a power-on control circuit that can stop power supply immediately after power-on and protect and protect the device when a failure occurs in a circuit of an electronic device.

  Here, the configuration and operation of a general AC adapter will be described.

  FIG. 2 is a block diagram showing an example of a detailed configuration of a general separately excited flyback converter type AC adapter.

  As shown in FIG. 2, the configuration of the AC adapter 201 includes a transformer 208 that converts a voltage.

  First, the configuration and operation of the transformer 208 on the primary circuit side will be described. On the primary circuit side, a plug 202 connected to the commercial power source 221, a rectifier circuit 203, a smoothing circuit 204, a switching element 205, a resistor 206, a control circuit 207, a transformer 208, and a photocoupler 211 are provided. I have.

  The commercial power source 221 supplies an AC voltage of AC 100 V (volt) to the AC adapter. The rectifier circuit 203 performs full-wave rectification on the supplied AC voltage and converts it into a pulsating flow. The smoothing circuit 204 smoothes the converted pulsating current into a DC voltage. The switching element 205 converts the smoothed DC voltage into a high-frequency pulse voltage and inputs it to the transformer 208. The transformer 208 steps down the high-frequency pulse voltage input from the primary circuit side to a predetermined voltage and outputs it to the secondary circuit side. The control circuit 207 on the primary circuit side receives the signal from the photocoupler 211 and is connected to the on / off control terminal of the primary circuit through the resistor 206.

  Next, the configuration and operation of the transformer 208 on the secondary circuit side will be described. On the secondary circuit side, a diode 209, an electrolytic capacitor 210, a feedback circuit 212, a plug 213, a transformer 208, and a photocoupler 211 are provided.

  The diode 209 and the electrolytic capacitor 210 smooth the pulse voltage stepped down to a predetermined voltage into a DC voltage. The plug 213 is connected to an electronic device (not shown) and supplies a DC voltage. The feedback circuit 212 is connected to the secondary circuit in order to control the supplied DC voltage to be stable, and transmits a signal via the photocoupler 211 to the control circuit 207 on the primary circuit side.

  As described above, the AC adapter 201 operates when the AC voltage of the commercial power source 202 is supplied.

JP2012-055085A JP 2012-022533 A

  When an incompatible AC adapter is used, an abnormal load current does not always flow, so there is a possibility that the overcurrent protection circuit on the AC adapter side, the fuse on the electronic device side, etc. will not operate. In such a case, there was a risk that the AC adapter would be overloaded. Or there was a risk that the electronic device would not operate normally.

  An object of the present invention is to provide an AC adapter and an AC adapter power supply determination method that solves this problem.

  The present invention relates to an AC adapter for supplying electric power to an electronic device, based on a transformer, current detection means disposed on the secondary side of the transformer, time measurement means, and current detected by the current detection means. The apparatus includes a determination unit that controls the time measurement unit and determines whether or not power can be supplied to the electronic device based on the time measured by the time measurement unit.

  The present invention is a method for determining power supply to an electronic device, wherein an inrush current flowing in the electronic device is detected after power is supplied to the electronic device by an AC adapter, and a predetermined load current is detected from the time of the inrush current detection. The time until detection is measured, and the time is compared with a predetermined time to determine whether power can be supplied to the electronic device.

  The AC adapter and the power supply determination method for the AC adapter according to the present invention can determine whether the AC adapter is compatible or not.

It is a block diagram which shows the structure of the AC adapter in the 1st Embodiment of this invention. It is a block diagram which shows an example of a detailed structure of the general separately excited flyback converter type AC adapter. It is a block diagram which shows an example of the detailed structure of the AC adapter in the 1st Embodiment of this invention. It is a block diagram which shows an example of a structure of the power input part of a general electronic device. It is a time chart of the operation example of the AC adapter in the 1st Embodiment of this invention. It is a flowchart of the operation example of the AC adapter in the 1st Embodiment of this invention. In the first embodiment of the present invention, when an AC adapter compatible with an electronic device is determined, it is an example of time defined in advance for each product during product development. It is a block diagram which shows an example of the detailed structure of the AC adapter in the 2nd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a block diagram showing a configuration of an AC adapter according to the first embodiment of the present invention.

  As shown in FIG. 1, the configuration of the AC adapter 101 in the first embodiment includes a transformation means 102, a current detection means 103, a determination means 104, and a time measurement means 105. The AC adapter 101 is connected to the commercial power supply 121 and the electronic device 141. The transformer means 102 includes a transformer for converting a voltage. The current detection unit 103 is a current detection unit that detects a current that flows when electric power is supplied to the electronic device 141. The determining unit 104 controls the driving and stopping of the time measuring unit 105 based on the current detected by the current detecting unit 103, and determines whether to continue or stop the power supply of the AC adapter based on this measurement time. The time measuring means 105 is a timer unit that measures time.

  FIG. 3 is a block diagram illustrating an example of a detailed configuration of the AC adapter according to the first embodiment of the present invention.

  As shown in FIG. 3, the configuration of the AC adapter 301 includes a transformer 308 that converts a voltage.

  First, the configuration and operation of the transformer 308 on the primary circuit side will be described. On the primary circuit side, a plug 302 connected to a commercial power source 321, a rectifier circuit 303, a smoothing circuit 304, a switching element 305, a first resistor 306, a control circuit 307, a transformer 308, a first photo A coupler 311 and a second photocoupler 317 are provided.

  The commercial power source 321 supplies an AC voltage of AC 100 V (volt) to the AC adapter. The rectifier circuit 303 performs full-wave rectification on the supplied AC voltage and converts it into a pulsating flow. The smoothing circuit 304 smoothes the converted pulsating current into a DC voltage. The switching element 305 converts the smoothed DC voltage into a high-frequency pulse voltage and inputs it to the transformer 308. The transformer 308 steps down the high-frequency pulse voltage input from the primary circuit side to a predetermined voltage and outputs it to the secondary circuit side. The control circuit 307 on the primary circuit side receives the signal from the first photocoupler 311 and is connected to the on / off control terminal of the primary circuit through the first resistor 306. Further, the control circuit 307 also receives a signal for stopping the power supply of the AC adapter from the second photocoupler 317.

  Next, the configuration and operation of the transformer 308 on the secondary circuit side will be described. On the secondary circuit side, a diode 309, an electrolytic capacitor 310, a feedback circuit 312, a plug 313, a transformer 308, a first photocoupler 311, a second resistor 313, a current detection unit 314, and a determination unit 315, a timer unit 316, a first photocoupler 311 and a second photocoupler 317.

  The diode 309 and the electrolytic capacitor 310 smooth the pulse voltage stepped down to a predetermined voltage into a DC voltage. The plug 313 is connected to an electronic device (not shown) and supplies a DC voltage. The feedback circuit 312 is connected to the secondary circuit in order to control the supplied DC voltage so as to be stable, and transmits a signal via the first photocoupler 311 to the control circuit 307 on the primary circuit side.

  The second resistor 313 is arranged in series with the secondary circuit of the transformer 308 in order to detect current. The current detector 314 is arranged in parallel with the second resistor 313 and detects the current of the secondary circuit. The determination unit 315 starts the time measurement of the timer unit 316 simultaneously with detecting the inrush current, and stops the time measurement of the timer unit 316 simultaneously with detecting the normal load current. The timer unit 316 measures the time from when the inrush current is detected to when the normal load current is detected.

  The inrush current is a large current that flows when electric power is supplied from the AC adapter to the electronic device. By detecting the inrush current, it can be seen that the power supply of the electronic device has been started.

  Then, the determination unit 315 receives the time measured by the timer unit 316 and compares the time defined for each product in advance during product development to determine whether the AC adapter power supply is continued or stopped. Here, when it is determined that the power supply of the AC adapter is stopped, the determination unit 315 transmits a signal to stop the power supply of the AC adapter to the control circuit on the primary circuit side through the second photocoupler 317. The determination unit 315 may be provided in a control circuit on the primary circuit side.

  As described above, the AC adapter 301 operates when the AC voltage of the commercial power source 321 is supplied.

  The time defined in advance for each product at the time of product development is the time defined by the manufacturer when determining the AC adapter that is compatible with the electronic device, from when the inrush current is detected until the normal load current is detected Is the inherent time of The manufacturer presets the defined time in the AC adapter and the electronic device.

  FIG. 4 is a block diagram illustrating an example of a configuration of a power input unit of a general electronic device.

  As shown in FIG. 4, the configuration of the power input unit 401 of the electronic device includes a jack 402 for connecting to an AC adapter, a power control IC 403, and a capacitor 404. The power supply control IC 403 converts the DC voltage input from the jack 402 into an arbitrary voltage, outputs it to the outside of the power supply input unit, and further has a soft start function. The soft start function is a function that can change the time during which the output voltage increases. The capacitor 404 is connected to the soft start function of the power supply control IC 403. When the product is developed, the manufacturer can change the time until the voltage is output depending on the capacitance value of the capacitor.

  Next, the operation of the present embodiment will be described in detail using a time chart.

  FIG. 5 is a time chart of an operation example of the AC adapter according to the first embodiment of the present invention.

  FIG. 5 shows the timing when the AC adapter is connected to the commercial power supply, the timing when the AC adapter is connected to the electronic device, and the time when power is supplied from the AC adapter to the electronic device 1, the electronic device 2, and the electronic device 3. Inrush current and load current measured on the secondary side of the AC adapter are represented on the same time axis.

  The timing for connecting the AC adapter and the commercial power supply is point P1 in the time chart of FIG. After the point P1, a voltage of AC 100V is supplied to the AC adapter.

  The timing for connecting the AC adapter and the electronic device is point P2 in the time chart of FIG. After the point P2, a voltage is supplied from the AC adapter to the electronic device.

  In the time chart of FIG. 5, the AC adapter and the commercial power source are first connected, and then the AC adapter and the electronic device are connected. However, the order may be reversed depending on the user's operation.

  A large inrush current 501 flows through the electronic device 1, the electronic device 2, and the electronic device 3 first, and then when the electronic device starts operating, a normal load current 502 flows.

  As described above, at the time of product development, the manufacturer predefines the time for the determination unit to compare based on the capacitance value of the capacitor in the power input unit. The electronic device 1, the electronic device 2, and the electronic device 3 are defined with different times (n1, n2, and n3).

  Next, the operation of the present embodiment will be described in detail using a flowchart.

  FIG. 6 is a flowchart of an operation example of the AC adapter according to the first embodiment of the present invention.

  As shown in FIG. 6, first, the AC adapter and the commercial power source are connected (step S601). Power is supplied to the AC adapter, and at this time, the time of the timer unit can be set (or reset) to 0 seconds.

  Next, the AC adapter and the electronic device are connected (step S602). However, depending on the user's operation, step S602 may be before S601.

  When the AC adapter is connected to the electronic device, the current detection unit detects an inrush current, and using the inrush current as a trigger, the timer unit starts measuring time (step S603). Alternatively, the determination unit starts the timer unit with the inrush current as a trigger.

  Next, the current detection unit detects the load current, and at the same time, the timer unit stops time measurement (step S604). Alternatively, the determination unit stops the timer unit.

  Next, the determination unit compares whether or not the measured time matches the defined time, and determines whether to continue or stop the power supply of the AC adapter (step S605).

  When the measured time matches the defined time (Yes in the figure), the determination unit does not transmit a power supply stop signal to the control circuit (step S606). Then, the power supply of the AC adapter continues, and the operation of the electronic device continues.

  On the other hand, when the measured time does not match the defined time (No in the figure), the determination unit transmits a power supply stop signal to the control circuit (step S607). Since the control circuit is connected to the power supply on / off control terminal, the power supply of the AC adapter is stopped and the operation of the electronic device is stopped.

  Next, an example of time defined by the manufacturer at the time of product development will be described using a table.

  FIG. 7 shows an example of the time defined for each product in advance when the product is developed when the AC adapter compatible with the electronic device is determined in the first embodiment of the present invention.

  In the case of the electronic device 1 and the AC adapter 1, the time (n1) is 0.5 to 1.0 seconds. In the case of the electronic device 2 and the AC adapter 2, the time (n2) is 1.0 to 1.5 seconds. 3 and AC adapter 3 are examples in which time (n3) is defined in advance as 1.0 to 1.5 seconds.

As described above, in the AC adapter that supplies power to the electronic device, the present invention can determine whether the AC adapter is compatible or non-compliant.
(Second Embodiment)
FIG. 8 is a block diagram illustrating an example of a detailed configuration of the AC adapter according to the second embodiment of the present invention.

  As shown in FIG. 8, the detailed configuration of the AC adapter 801 is connected to a feedback winding in which a switching element 205 is wound around a transformer 208.

  In the second embodiment, the switching element 205 has the same configuration as that of the first embodiment except that the switching element itself performs a self-excited transmission by a feedback winding wound around the transformer 208. Have. Therefore, the same components as those in the second embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  Since the current detection unit, timer unit, determination unit, feedback circuit, and control circuit of the second embodiment are controlled with the same configuration as that of the first embodiment, they have the same effects as those of the first embodiment. .

  In addition, this invention is not limited to the above-mentioned embodiment, It can implement in various changes and deformation | transformation in the range which does not deviate from the summary of this invention.

101, 201, 301, 801 AC adapter 102 Transform means 103 Current detection means 104 Judgment means 105 Time measurement means 121, 221, 321 Commercial power supply 141 Electronic equipment 202, 302 Plug 203, 303 Rectifier circuit 204, 304 Smoothing circuit 205, 305 Switching element 206 Resistance 207, 307 Control circuit 208, 308 Transformer 209, 309 Diode 210, 310 Electrolytic capacitor 211 Photocoupler 212, 312 Feedback circuit 213, 313 Plug 306 First resistance 311 First photocoupler 313 Second resistance 314 Current Detection unit 315 Determination unit 316 Timer unit 317 Second photocoupler 401 Power input unit 402 Jack 403 Power control IC
404 Capacitor 501 Inrush current 502 Load current

Claims (9)

  In an AC adapter for supplying electric power to an electronic device, a transformer, current detection means disposed on the secondary side of the transformer, time measurement means, and the time measurement means based on the current detected by the current detection means An AC adapter comprising: determination means for controlling whether or not to supply power to the electronic device based on the time measured by the time measurement means.   Power supply control means for controlling power supply to the electronic device, wherein the determination means sends a signal for stopping the power supply when the measured time is different from a predetermined time by a predetermined time or more. The AC adapter according to claim 1, wherein the AC adapter is transmitted to the computer.   The determination means controls the time measurement means to determine whether or not to supply power to the electronic device based on a time from when an inrush current flowing in the electronic device is detected until a predetermined load current is detected. The AC adapter according to claim 1 or 2.   The AC adapter according to claim 2 or 3, wherein the predetermined time is held in the AC adapter.   The AC adapter according to claim 2, 3, or 4, wherein the predetermined time is a value unique to an electronic device corresponding to the AC adapter.   The AC adapter according to claim 2, wherein the power supply control unit includes a function of the determination unit.   A method for determining power supply to an electronic device, the method comprising: detecting an inrush current flowing in the electronic device after supplying power to the electronic device by an AC adapter, and detecting a predetermined load current from the time of the inrush current detection And determining whether or not power can be supplied to the electronic device by comparing the time with a predetermined time.   The power supply determination method according to claim 7, wherein the predetermined time is held in the AC adapter.   The power supply determination method according to claim 7 or 8, wherein the predetermined time is a value unique to an electronic device corresponding to the AC adapter.

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