JP4125686B2 - Power consumption reduction circuit and power consumption reduction method - Google Patents

Description

  The present invention relates to a power consumption reduction circuit and a power consumption reduction method, and more particularly to a power consumption reduction circuit configured in an AC adapter and a power consumption reduction method using the circuit.

  As a power supply device that supplies DC power to devices such as various home appliances and OA devices used at home, DC current is generated by rectifying and smoothing commercial AC current, and this current is adapted to the load side device by switching control. AC adapters that convert voltage are widely used.

  In this AC adapter, from the viewpoint of power saving, it is possible to reduce power consumption at low load and no load, such as when the load side device is in standby mode or when the load side device is disconnected from the AC adapter. Very important. In particular, when the load side device and the AC adapter are disconnected, the power consumed by the AC adapter is completely wasted power. In order to reduce such wasteful power, conventionally, a power consumption reduction circuit that reduces the power consumption by changing the switching oscillation period of the AC adapter to an intermittent oscillation state has been used (for example, JP 2000-69747 A).

  In the above publication, the voltage on the load side, which is the secondary output terminal of the AC adapter, is monitored, and when the device load shifts to a light load and the output voltage increases, an excitation current flows through the relay coil and the primary side switch The relay contact of the circuit is turned off, the primary circuit is cut off, and the operation stops. When the voltage on the load side decreases due to the interruption of the primary circuit, the exciting current of the relay coil is interrupted, the relay contact on the primary side is turned on, and the primary circuit returns to the operating state. By intermittently repeating the ON / OFF operation of the above relay contacts, the AC adapter will not always operate when the device load is light or no load, and power consumption will be consumed only during the period when the operation is intermittently stopped. It becomes possible to reduce.

JP 2000-69747 (page 2-3, FIG. 1)

  However, since the power consumption reduction circuit for the AC adapter described in the above publication continues the switching operation intermittently even when the AC adapter and the load side device are disconnected, there is a limit to reducing the power consumption. There was a problem that further power saving could not be achieved.

  The present invention has been made in view of the above problems, and a first object thereof is a power consumption reduction circuit capable of reducing power consumption when the output side of the AC adapter is in a no-load state, and power consumption. It is to provide a reduction method.

  In addition, a second object of the present invention is to provide a power consumption reduction circuit and a power consumption reduction method capable of realizing the process of returning the switching operation when an apparatus is connected to the AC adapter inside the AC adapter. It is in.

In order to achieve the above object, a power consumption reduction circuit according to the present invention is a power consumption reduction circuit configured in an AC adapter including a transformer that supplies power to a device, and includes a resistor connected to a secondary side of the transformer. Detecting means for receiving the voltage across the resistor, first transmission means controlled by the output of the detecting means, a capacitor connected to the secondary side of the transformer, and charging the capacitor Second transmission means controlled by the charged electric charge, first switch means connected to the primary side of the transformer and controlled to be switched by the first transmission means and the second transmission means, at least a switching control circuit for controlling the switching operation of the transformer in accordance with the state of the first switch means, said detecting means, output when no current flows in the resistor The first transmission means operates to turn off the first switch means when the output of the detection means is HIGH, and the second transmission means When the device is connected to the AC adapter and a charge charged in the capacitor is supplied through a path provided in advance in the device, the device operates to turn on the first switch means. The switching control circuit operates to stop the switching operation of the transformer when the first switch means is OFF, and to restore the switching operation of the transformer when the first switch means is ON. it is shall be operating.

Further, in the present invention, a second switch unit controlled by an output of the detection unit is further provided between the capacitor and the second transmission unit, and the second switch unit includes the device. And the AC adapter are connected, and when the output of the detection means is HIGH, the capacitor and the second transmission means can be connected.

Further, the current consumption reduction method of the present invention is a method for reducing power consumption of an AC adapter including a transformer for supplying power to the device, the resistor connected to the secondary side of the transformer, and both ends of the resistor. The control means is controlled by the detection means that receives the voltage of the first input, the first transmission means controlled by the output of the detection means, the capacitor connected to the secondary side of the transformer, and the charge charged in the capacitor. A second transmission means, a first switch means connected to a primary side of the transformer and controlled to be switched by the first transmission means and the second transmission means; and a first switch means At least a switching control circuit for controlling the switching operation of the transformer according to the state, and the output of the detection means is high when no current flows through the resistor And operating the first transmission means to turn off the first switch means when the output of the detection means is HIGH, and the second transmission means is connected to the device and the AC adapter. Is connected, and when the electric charge charged in the capacitor is supplied via a path provided in advance in the device, the first switch means is operated to be turned on, and the switching control circuit is operated. Operating the transformer so that the switching operation of the transformer is stopped when the first switch means is OFF, and returning the switching operation of the transformer when the first switch means is ON, When the AC adapter is not connected to the AC adapter, the switching operation of the transformer is stopped. Ru Monodea to reduce the consumption.

Further, in the present invention, a second switch means controlled by an output of the detection means is further provided between the capacitor and the second transmission means, and the second switch means is connected to the device. And the AC adapter are connected, and the capacitor and the second transmission means can be connected to each other when the output of the detection means is HIGH.

  Thus, the power consumption reduction circuit according to the present invention detects the charging current flowing to the output side using the resistor and the detecting means, and uses the first transmission means controlled by the output of the detecting means to use the charging current. The power consumption of the AC adapter in the no-load state is reduced by controlling the AC adapter to switch when the battery is flowing, and to stop the switching operation of the ACAC adapter when the charging current is not flowing Can do. In addition, the capacitor is provided in the AC adapter, and the device is connected to the AC adapter by providing a path for connecting the capacitor and the second transmission means controlled by the electric charge charged in the capacitor. In this case, the switching operation can be recovered from the stopped state using the electric charge charged in the capacitor.

  According to the power consumption reduction circuit and the power consumption reduction method using the circuit of the present invention, the following effects can be obtained.

  The first effect of the present invention is that power consumption when the output side of the AC adapter is in a no-load state can be reduced.

  The reason is that a current detection resistor and detection means are provided on the output side of the AC adapter to detect the charging current flowing on the output side, and a first transmission means controlled by the output of the detection means is provided to allow the charging current to flow. This is because the AC adapter is switched to supply power to the output while the charging current is not flowing, and the AC adapter is controlled to stop the switching operation.

  The second effect of the present invention is that the processing for returning the switching operation from the stopped state can be realized inside the AC adapter.

  The reason is that a starting capacitor is provided in the AC adapter, and a path for connecting the starting capacitor and the second transmission means controlled by the electric charge charged in the starting capacitor is formed in the apparatus. Thus, when the device is connected to the AC adapter, the switching operation can be restored using the charge charged in the starting capacitor.

  In a preferred embodiment of the power consumption reduction circuit of the present invention, a current detection resistor and detection means provided on the output side of the transformer in the AC adapter, and a first transmission means controlled by the output of the detection means, A starting capacitor provided on the output side of the transformer, a second transmission means controlled by the electric charge charged in the starting capacitor, and a switch means that switches according to the state of the first transmission means and the second transmission means A switching control circuit for controlling a switching operation according to the state of the switching means, and a switching means for detecting a charging current according to the presence or absence of connection between the AC adapter and the device and supplying power to the switching control circuit. By switching, the switching operation can be stopped in a no-load state to reduce power consumption. Further, when the device is connected to the AC adapter, the charge of the starting capacitor can be supplied to the second transmission means via a path previously provided on the device side to turn on the switch means to return the switching operation. it can.

  In order to describe the above-described embodiment of the present invention in more detail, a power consumption reduction circuit and a power consumption reduction method according to a first example of the present invention will be described with reference to FIG. FIG. 1 is a circuit diagram showing a configuration of a power consumption reduction circuit according to the present embodiment.

  As shown in FIG. 1, the power consumption reduction circuit according to the present embodiment is configured in an AC adapter 1 connected to the device 11, and each of the AC adapter 1 and the device 11 is supplied with a charging current from the AC adapter. A pair of power supply terminals and a pair of connection terminals for forming a path for returning to the switching operation when the AC adapter 1 and the device 11 are connected are provided.

  The AC adapter 1 including the power consumption reduction circuit rectifies and smoothes the input AC current and supplies the current to the primary side of the transformer, and the primary side current is switched and oscillated. Switching control circuit 5 for performing control, switch means 3 for supplying power to switching control circuit 5, current detection resistor 6 and detection means 10 for detecting current flowing on the secondary side of the transformer, and detection means 10 Depending on the output, when the charging current is flowing, it is not transmitted to the switching means 3, and when the charging current is not flowing, the first transmitting means 8 is transmitted to the switching means 3, and the charge is accumulated in the apparatus when the apparatus is connected. The start capacitor 7 for supplying power to the second transmission means 9 by bypassing the second transmission means 9 and the second transmission means 9 for transmitting that the device 11 is connected while the switching operation is stopped are mainly provided. It is a component. The switch means 3 is composed of a thyristor 3a, a transistor 3b, and a capacitor 3c, and the first transmission means 8 and the second transmission means 9 separate the primary power system and the secondary power system of the transformer. In order to achieve this, a photo coupler is used.

  In addition, the device 11 is provided with a charging power supply circuit 12 and a battery 13 at the interface with the AC adapter 1, the pair of power supply terminals are connected to the charging control circuit 12, and the pair of connection terminals are internally provided. They are connected by the formed wiring.

  The operation of the AC adapter 1 having the above configuration will be described. First, when the AC adapter 1 is connected to an outlet, the transistor 3b is turned on until the potential of the capacitor 3c in the switch means 3 rises, and a signal is given to the gate of the thyristor 3a in the switch means 3 to turn on the thyristor 3a. become. When the thyristor 3a is turned on, power is supplied to the switching control circuit 5 and a voltage is generated on the output side of the transformer. As a result, charges are accumulated in the starting capacitor 7.

  At this time, if the device 11 is not connected to the output, no voltage is generated at both ends of the current detection resistor 6, so that the output of the detection means 10 becomes HIGH, and the first transmission means 8 causes the thyristor in the switch means 3. The gate of 3a is connected to GND. Thereby, the thyristor 3a is turned off, the power supply to the switching control circuit 5 is stopped, and the switching operation is stopped. Therefore, power consumption in a no-load state is reduced.

  Further, when the device 11 is connected to the AC adapter 1 while the switching operation is stopped, a path connected from the starting capacitor 7 through the device 11 to the second transmission means 9 is formed and accumulated in the starting capacitor 7. A current flows through the second transmission means 9 due to the generated charge, and the capacitor 3c in the switch means 3 is connected to GND. Then, the transistor 3b in the switch means 3 is turned on, a signal is given to the gate of the thyristor 3a in the switch means 3, and the thyristor 3a is turned on. As a result, power is supplied to the switching control circuit 5, and the AC adapter 1 is restarted to generate a voltage on the output side. Therefore, when the device 11 is connected from the no-load state, the circuit can be returned to the switching operation by the circuit provided in the AC adapter 1.

  Further, there is a charging completion state as a case where the charging current does not flow. When charging is completed, the output of the detection means 10 becomes HIGH, the thyristor 3a of the switch means 3 is turned OFF by the first transmission means 8, and the operation until the switching operation is stopped is the same as described above. In this case, since the AC adapter 1 and the device 11 remain connected, the switch means 3 is turned on again through the second transmission means 9 by the charge of the starting capacitor 7, and the switching operation is resumed. However, since the charging current is not flowing, the switching operation is stopped again when the discharge of the starting capacitor 7 is completed. As described above, when the charging is completed, an intermittent operation in which the switching operation is started and stopped is repeated.

  In this way, the charging current flowing to the device 11 side is detected using the current detection resistor 6 and the detection means 10, and the state of the first transmission means 8 and the first transmission means 8 controlled by the output of the detection means 10 is obtained. Using the switching means 3 and the switching control circuit 5 that switch in response, the AC adapter 1 is switched to supply power to the output when the charging current flows, and the AC adapter 1 when the charging current does not flow. Can be stopped, and the power consumption of the AC adapter 1 in a no-load state can be reduced. Further, a starting capacitor 7 is provided in the AC adapter 1, and a path for connecting the starting capacitor 7 and the second transmission means 9 controlled by the electric charge charged in the starting capacitor 7 is formed in the device 11. Thus, it is possible to return to the switching operation when the device 11 is connected using the charge charged in the starting capacitor 7.

  Next, a power consumption reduction circuit and a power consumption reduction method according to a second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a circuit diagram showing the configuration of the power consumption reduction circuit of this embodiment.

  In the circuit of the first embodiment shown in FIG. 1, when charging is completed with the device 11 connected, the charging current stops flowing, so the switching operation of the AC adapter 1 becomes an intermittent operation, and the switching operation is completely stopped. I can't. Therefore, in this embodiment, the circuit is configured so that the switching operation is stopped when the charging is completed in the device connection state, and the power consumption can be further reduced.

  Specifically, as shown in FIG. 2, the AC adapter 1 of this embodiment includes a rectifying / smoothing circuit 2 that rectifies and smoothes an input AC current and supplies current to the primary side of the transformer, A switching control circuit 5 for controlling the oscillation of the primary side current, switch means 3 for supplying power to the switching control circuit 5, a current detection resistor 6 for detecting a current flowing on the secondary side of the transformer, and According to the output of the detection means 10 and the detection means 10, the first transmission means 8 that does not transmit to the switch means 3 when the charging current flows, and transmits to the switch means 3 when the charging current does not flow, A start-up capacitor 7 that accumulates electric charge and bypasses the inside of the apparatus when the apparatus is connected to supply power to the second transmission means 9, and a second transmission for transmitting that the apparatus 11 is connected while the switching operation is stopped In addition to the stage 9, the charge of the starting capacitor 7 is supplied to the second transmitting means 9 when the charging current is flowing by the output of the detecting means 10, and when the charging current is not flowing, the charge of the starting capacitor 7 is supplied. Second switch means 4 is added to operate so as not to supply charges to the second transmission means 9.

  The operation of the AC adapter 1 having the above configuration will be described. The operation when the device 11 is not connected to the AC adapter 1 and when the device 11 is connected and charging is not completed is the first operation described above. As in the embodiment, when the device 11 is connected to the AC adapter 1 and the charging is completed, the charging current does not flow through the current detection resistor 6, so that the output of the detection means 10 becomes HIGH, and the second switch means 4 is turned OFF, and the signal to the second transmission means 9 is cut off. On the other hand, the gate of the thyristor 3a in the switch means 3 is connected to GND by the first transmission means 8 and is turned OFF, and the power supply to the switching control circuit 5 is stopped. As a result, the switching operation is stopped when the charging is completed, and the power consumption is further reduced as compared with the first embodiment.

  In this way, in addition to the configuration of the first embodiment, the output of the detection means 10 supplies the charge of the starting capacitor 7 to the second transmission means 9 when the charging current is flowing, and the charging current is flowing. By providing the second switch means 4 that operates so as not to supply the charge of the starting capacitor 7 to the second transmission means 9 when there is no charge, the switching operation is stopped even when the charging is completed in the connected state of the device. Reduction can be achieved.

  The above embodiment is an example of the power consumption reduction circuit of the present invention. The switch means 3, the switching control circuit 5, the resistance element and the charge storage element connected to the secondary side, the first transmission means 8, the second transmission. It is only necessary to include the means 9, the detection means 10, and the second switch means 4 as necessary, and the configuration of each means and the arrangement on the circuit can be appropriately set. A circuit element may be included.

1 is a circuit diagram showing a configuration of a power consumption reduction circuit according to a first example of the present invention. FIG. It is a circuit diagram which shows the structure of the power consumption reduction circuit which concerns on the 2nd Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 AC adapter 2 Rectification / smoothing circuit 3 Switch means (1st switch means)
3a Thyristor 3b Transistor 3c Capacitor 4 Second switch means 5 Switching control circuit 6 Current detection resistor 7 Start capacitor 8 First transmission means 9 Second transmission means 10 Detection means 11 Device 12 Charging control circuit 13 Battery

Claims (4)

A power consumption reduction circuit configured in an AC adapter including a transformer for supplying power to the device,
A resistor connected to the secondary side of the transformer, a detection means for inputting a voltage across the resistor, a first transmission means controlled by the output of the detection means, and a secondary side of the transformer A capacitor to be connected, a second transmission means controlled by the charge charged in the capacitor, and a primary side of the transformer, which are switched by the first transmission means and the second transmission means. First switching means to be controlled, and at least a switching control circuit for controlling the switching operation of the transformer according to the state of the first switching means ,
The detection means operates so that the output becomes HIGH when no current flows through the resistor,
The first transmission means operates to turn off the first switch means when the output of the detection means is HIGH;
The second transmission means is connected to the device and the AC adapter, and when the electric charge charged in the capacitor is supplied through a path provided in the device in advance, the first switch Operates to turn the means ON,
The switching control circuit operates to stop the switching operation of the transformer when the first switch means is OFF, and operates to return the switching operation of the transformer when the first switch means is ON. power reduction circuit according to claim to Rukoto. Furthermore, a second switch means controlled by the output of the detection means is provided between the capacitor and the second transmission means,
The second switch means operates to connect the capacitor and the second transmission means when the device and the AC adapter are connected and the output of the detection means is HIGH. The power consumption reduction circuit according to claim 1 . A method for reducing power consumption of an AC adapter comprising a transformer for supplying power to a device, comprising:
A resistor connected to the secondary side of the transformer, a detection means for inputting a voltage across the resistor, a first transmission means controlled by the output of the detection means, and a secondary side of the transformer A capacitor to be connected, a second transmission means controlled by the charge charged in the capacitor, and a primary side of the transformer, which are switched by the first transmission means and the second transmission means. First switching means to be controlled, and at least a switching control circuit for controlling the switching operation of the transformer according to the state of the first switching means,
Operating the detection means so that the output is HIGH when no current flows through the resistor;
Operating the first transmission means to turn off the first switch means when the output of the detection means is HIGH;
When the device and the AC adapter are connected to each other, the second switch is connected to the first switch when a charge charged in the capacitor is supplied through a path provided in the device in advance. Operate to turn the means ON,
The switching control circuit is operated so that the switching operation of the transformer is stopped when the first switch means is OFF, and the switching operation of the transformer is returned when the first switch means is ON. A power consumption reduction method characterized by reducing power consumption of the AC adapter by operating and stopping the switching operation of the transformer when the device and the AC adapter are not connected . Furthermore, a second switch means controlled by the output of the detection means is provided between the capacitor and the second transmission means,
The second switch means is operated to connect the capacitor and the second transmission means when the device and the AC adapter are connected and the output of the detection means is HIGH. The power consumption reduction method according to claim 3 .

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