JP2015180159A - Voltage supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply device for supplying voltage needed for operation of a product while detecting a frequency of input AV voltage.SOLUTION: There is provided a voltage supply circuit configured so as to be capable of converting AC voltage input from an input terminal (10, 11) to predetermined DC voltage and outputting the converted voltage from an output terminal (20, 21) to a functional circuit. The voltage supply circuit comprises: a frequency detection unit (frequency detection circuit 410) configured so as to be capable of detecting a frequency of the AC voltage on the basis of a ripple generated based on the AC voltage; a dummy resistor (dummy resistor 70) configured so as to be capable of increasing load resistance of the functional circuit connected to the output terminal; and a control unit (control circuit 60) capable of controlling the dummy resistor so as to make the dummy resistor be in a conduction state when the frequency detection unit executes frequency detection (refer to S820) and be in a non-conduction state when the functional circuit performs normal operation (refer to S860).

Description

  One embodiment of the present invention relates to a voltage supply device that supplies a voltage necessary for the operation of a product while detecting the frequency of an AC voltage input as a power supply voltage.

  Conventionally, in order to appropriately control a triac used in an electric circuit, it is identified whether the frequency of an AC voltage that is a power supply voltage input to the power supply circuit is 50 Hz or 60 Hz. In order to detect the frequency of such a power supply voltage, a method using a commercial ripple has been conventionally used. For example, Patent Literature 1 and Patent Literature 2 disclose devices for detecting a power supply frequency.

JP 2003-66071 A Japanese Utility Model Publication No. 2000-54

  As described above, in the power supply circuit, the commercial ripple is used to detect the frequency. However, in order to detect the frequency appropriately, it is necessary to generate a ripple having a certain size. However, if the capacity of the electrolytic capacitor connected to the primary side of the power supply circuit is increased in order to increase the ripple, there is a problem that the voltage supplied from the power supply circuit becomes unstable when the power supply voltage is momentarily interrupted. On the other hand, if the output current on the secondary side of the power supply circuit is increased in order to increase the ripple, there is a problem that the power consumption increases.

  The present invention has been made to solve the above-described problems, and provides a voltage supply device capable of detecting the frequency of a power supply voltage while simultaneously achieving stable supply voltage and suppressing power consumption. It is aimed.

  The present invention adopts the following means in order to solve the above problems. In the following description, in order to facilitate understanding of the invention, reference numerals and the like in the drawings are appended in parentheses, but each component of the present invention is not limited to these appendices. It should be construed broadly to the extent that contractors can technically understand.

Means 1 of the present invention include
A voltage supply device configured to convert an AC voltage input from an input terminal (10, 11) into a predetermined DC voltage and output the voltage from the output terminal (20, 21) to a functional circuit,
A frequency detection unit (frequency detection circuit 410) configured to be able to detect the frequency of the AC voltage based on the ripple generated based on the AC voltage;
A dummy resistor (dummy resistor 70) configured to increase the load resistance of the functional circuit connected to the output terminal;
The dummy resistor can be controlled to be in a conductive state when the frequency detection unit executes frequency detection (see S820) and to be in a non-conductive state when the functional circuit performs a normal operation (see S860). And a control unit (control circuit 60).

Means 2 of the present invention
A primary circuit (30) connected to the input terminal;
A secondary circuit (40) connected to the output terminal and electrically connected to the primary circuit via a transformer (50),
The frequency detection unit is a voltage supply device of the means 1, which is arranged in the secondary side circuit.

  According to the voltage supply device having the above configuration, the dummy resistor can be turned on only during the period when the frequency of the AC voltage (power supply voltage) is detected, and the dummy resistor can be turned off during other periods. Become. As a result, the ripple is increased during the period of detecting the frequency of the AC voltage, facilitating the detection of the frequency, and the power consumption increases when the functional circuit that supplies the voltage operates normally. Can be suppressed. Further, since the dummy resistor becomes non-conductive when the functional circuit operates normally, an increase in power consumption can be suppressed.

Means 3 of the present invention
The control unit (control circuit 60) is configured to be controllable so that the functional circuit becomes a maximum load when the frequency detection unit executes frequency detection. This is a power supply device.

  According to the voltage supply device having the above-described configuration, the ripple can be further increased during the period in which the frequency of the AC voltage is detected, so that the frequency detection can be further facilitated.

The figure which shows the structure of a voltage supply apparatus. FIG. 3 is a flowchart illustrating frequency detection processing according to the first embodiment. FIG. 10 is a diagram illustrating a flowchart of frequency detection processing in the second embodiment. FIG. 10 is a diagram illustrating a flowchart of frequency detection processing according to the third embodiment.

An embodiment according to the present invention will be specifically described according to the following configuration with reference to the drawings. However, the embodiment described below is merely an example of the present invention and does not limit the technical scope of the present invention. In addition, in each drawing, the same code | symbol is attached | subjected to the same component and the description may be abbreviate | omitted.
1. Embodiment 1
(1) Configuration example of voltage supply device (2) Specific example of frequency detection processing (3) Features of voltage supply device Embodiment 2
3. Embodiment 3
4). Supplementary matter

<1. Embodiment 1>
First, Embodiment 1 of the present invention will be described with reference to FIGS.

<(1) Configuration Example of Voltage Supply Device>
FIG. 1 is a diagram illustrating a configuration of a voltage supply apparatus according to the present embodiment. As shown in FIG. 1, the voltage supply apparatus according to the present embodiment is configured to be able to output a commercial AC voltage as a power supply voltage input from input terminals 10 and 11 from output terminals 20 and 21. The output terminals 20 and 21 are connected to a functional circuit for realizing the function of the electronic device configured to include the power supply voltage device. The functional circuit refers to an entire circuit to which a power supply device supplies voltage, such as an electronic circuit for realizing the function of a television and a display control circuit. In the power supply device, a primary side circuit 30, a secondary side circuit 40, a transformer 50, a control circuit 60, a switch 610, and a dummy resistor 70 are connected between the input terminals 10 and 10 and the output terminals 20 and 21. Configured.

<Primary circuit 30>
The primary side circuit 30 is a circuit in which an AC voltage is input from the input terminals 10 and 11 and before the transformer 50. The primary side circuit 30 includes an electrolytic capacitor connected between the input terminals 10 and 11.

<Secondary side circuit 40>
The secondary side circuit 40 generates a predetermined DC voltage by rectifying and stepping down the AC voltage that has been stepped down and transmitted to the primary side circuit 30 via the transformer 50, and generates a predetermined DC voltage from the output terminals 20 and 21. It is configured to allow output. One of the output terminals 20 and 21 of the secondary circuit 40 is a predetermined potential (for example, 24 V), and the other is a ground potential (GND). In the present embodiment, the output voltage from the secondary circuit 40 is described as being supplied with a pair of voltages from the output terminals 20 and 21, but includes an output voltage supplied with a plurality of voltages. The secondary side circuit 40 includes a frequency detection circuit 410.

<Frequency detection circuit 410>
The frequency detection circuit 410 is configured to detect a ripple voltage based on the voltage rectified with respect to the AC voltage transmitted to the secondary side circuit 40, and to detect the frequency of the input voltage based on the ripple voltage. The

<Transformer 50>
The transformer 50 is disposed between the primary side circuit 30 and the secondary side circuit 40 to electrically connect these circuits, and appears on the output side (transformer side) of the primary side circuit 30. The voltage is transmitted to the input side (transformer side) of the secondary circuit 40 while being stepped down.

<Control circuit 60>
The control circuit 60 is configured to be able to control the triac arranged in the apparatus based on the frequency detected by the frequency detection circuit 410. The control circuit 60 is configured to be able to control the conduction and non-conduction states of the switch 610. At this time, the control circuit 60 starts supplying the input voltage to the input terminals 10 and 11, turns on the switch 610 when performing the frequency detection in the frequency detection circuit 410, and sets the frequency in the frequency detection circuit 410. It is configured to be able to execute control to turn off the switch 610 when detection is completed. The operation in the control circuit 60 will be specifically described in the frequency detection process described later.

<Switch 610>
The switch 610 is formed of a transistor element, and is configured to be able to be turned on and off by a voltage supplied from the control circuit 60. The switch 610 is configured to be conductive at both ends in the on state and non-conductive at both ends in the off state. In particular, in this embodiment, as shown in FIG. 1, a dummy resistor 70 is connected in series with the dummy resistor 70 between the output terminals 20 and 21, and in the ON state, the dummy resistor 70 disposed between the output terminals 20 and 21 is connected. The dummy resistors 70 are arranged so as to be in a conductive state and in a non-conductive state in the off state. Note that the switch 610 is not necessarily a transistor element, and may be replaced as long as it can be turned on and off.

<Dummy resistor 70>
As shown in FIG. 1, the dummy resistor 70 is connected in series with the switch 610 between the output terminals 20 and 21, and is configured to increase the load resistance of the functional circuit in a conductive state. As described above, the switch 610 is placed in a conducting state while the switch 610 is in an off state, and is placed in a non-conducting state. The dummy resistor 70 is a resistance element having an arbitrary resistance value until the overcurrent protection is activated.

<(2) Specific example of frequency detection processing>
Next, a specific example of frequency detection processing in the voltage supply apparatus of the present embodiment will be described with reference to FIG.

<S800 to S810>
FIG. 2 is a flowchart showing a specific example of frequency detection processing in the power supply apparatus. In the frequency detection process (S800), first, when the power of the electronic device including the power supply device is turned on, the control circuit 60 detects the power-on (S810). At this time, no voltage is supplied to the functional circuit connected to the output terminals 20 and 21 of the power supply device.

<S820>
Next, before detecting the frequency of the AC voltage of the power supply voltage, the control circuit 60 turns on the switch 610 and changes the dummy resistor 70 from the non-conductive state to the conductive state (S820).

<S830>
Then, the control circuit 60 observes whether the frequency detection circuit 410 has appropriately detected the frequency of the power supply voltage applied to the input terminals 10 and 11 (S830). Whether or not the frequency detection circuit 410 by the control circuit 60 has properly detected the frequency of the power supply voltage, that is, whether or not the detection has been completed, determines that the detected frequency is either 50 Hz or 60 Hz. To condition. For example, when the detected frequency is 55 Hz or a completely different frequency, the control circuit 60 determines that the frequency detection circuit 410 has not detected the frequency appropriately.

<S830 to S840>
When the frequency detection circuit 410 cannot properly detect the frequency of the power supply voltage (N in S830), the control circuit 60 sets the frequency for a predetermined number of times (for example, 10 times every 0.5 seconds). Observation of the frequency detection state in the detection circuit 410 is repeated (retry). If the frequency detection state in the frequency detection circuit 410 by the control circuit 60 has not been observed a predetermined number of times (10 times) (N in S840), the frequency detection is repeated (return to S830). .

<S850>
When observation of the frequency detection state in the frequency detection circuit 410 by the control circuit 60 has been executed a predetermined number of times (10 times) (Y in S840), the frequency of the power supply voltage is fixed to 50 Hz or 60 Hz. It is regarded as a frequency (S850). The fixed frequency here is set in advance for each shipping destination of the electronic device (product) including the voltage supply device. For example, if this electronic device is shipped to North America, the frequency of the power supply voltage is regarded as 60 Hz, and if it is shipped to China, the frequency of the power supply voltage is regarded as 50 Hz. After the processing here, the frequency detection processing moves to processing of S860.

<S860 to S870>
When the frequency detection circuit 410 can appropriately detect the frequency of the power supply voltage (Y in S830), or when the frequency of the power supply voltage is regarded as a fixed frequency (S850), in both cases, the frequency detection of the power supply voltage is completed. The control circuit 60 turns off the switch 610 and switches the dummy resistor 70 from the conductive state to the non-conductive state (S860). In this way, the frequency detection process ends (S870). After this frequency detection process, the control circuit 60 controls the triac and the like so as to operate appropriately at the frequency detected here.

<(3) Features of power supply device>
As described above, the frequency of the power supply voltage connected to the input terminals 10 and 11 is detected by the power supply apparatus having the configuration as described above. That is, the power supply device of this embodiment has the following characteristics.

  The power supply device according to the present embodiment converts the AC voltage input from the input terminals (10, 11) into a predetermined DC voltage, and supplies the voltage from the output terminals (20, 21) to the functional circuit. A frequency detection unit (frequency detection circuit 410) configured to be able to detect the frequency of the AC voltage based on a ripple generated based on the AC voltage (power supply voltage) and an output terminal The dummy resistor (70) configured to increase the load resistance of the functional circuit and the dummy resistor are brought into a conductive state when the frequency detection unit executes frequency detection (see S820), and the functional circuit operates normally. And a control unit (control circuit 60) that can be controlled to be in a non-conductive state (see S860).

  The voltage supply device having the above configuration includes a primary circuit (30) connected to the input terminals (10, 11) and a primary circuit and a transformer (50) connected to the output terminals (20, 21). And a secondary circuit (40) electrically connected to each other, and the frequency detector (410) is arranged in the secondary circuit (40).

  According to the voltage supply device having the above configuration, the dummy resistor can be turned on only during the period when the frequency of the AC voltage (power supply voltage) is detected, and the dummy resistor can be turned off during other periods. Become. As a result, the ripple is increased during the period of detecting the frequency of the AC voltage, facilitating the detection of the frequency, and the power consumption increases when the functional circuit that supplies the voltage operates normally. Can be suppressed. Further, since the dummy resistor becomes non-conductive when the functional circuit operates normally, an increase in power consumption can be suppressed.

<2. Second Embodiment>
Next, Embodiment 2 of the present invention will be described with reference to FIG. The present embodiment is different from the first embodiment in that the processes of S820 and S860 are replaced with the processes of S821 and S861, respectively. Specifically, the control circuit 50 is different in that the function circuit is set to a maximum load state instead of turning on the dummy resistor 70 when detecting the frequency. In the following description, only differences from the first embodiment will be specifically described, and descriptions of functions and processes similar to those of the first embodiment will be omitted.

<S821>
As shown in FIG. 3, after the process of S810, the control circuit 60 controls the load of the functional circuit connected to the output terminals 20 and 21 of the power supply device to be in a maximum state (S821). Specifically, each unit is controlled so that the power consumption in the electronic device including the power supply device is maximized. For example, control is performed such that the television is displayed in the brightest state of white on the entire surface and all the LEDs that can be lit are turned on.

<S861>
When the frequency detection circuit 410 can appropriately detect the frequency of the power supply voltage (Y in S830), or when the frequency of the power supply voltage is regarded as a fixed frequency (S850), the control circuit 60 sets the load of the functional circuit in the normal state. (S861). In this way, the frequency detection process ends (S870).

  As described above, the frequency of the power supply voltage connected to the input terminals 10 and 11 is detected by the power supply apparatus having the configuration as described above. That is, the power supply device of this embodiment has the following characteristics.

  According to the power supply device having the above configuration, the ripple of the voltage used in the frequency detection circuit 410 can be increased without adding a special configuration including the dummy resistor 70 described in the first embodiment. As a result, it is possible to appropriately detect the frequency of the power supply voltage.

<3. Embodiment 3>
Next, Embodiment 3 of the present invention will be described with reference to FIG. In the present embodiment, the processing of S840 and S850 is replaced with the processing of S820, S830A, and S840 to S860, as compared with the second embodiment. The present embodiment is a form in which the first embodiment and the second embodiment are combined. In the following description, only differences from the second embodiment will be specifically described, and descriptions of functions and processes similar to those of the second embodiment will be omitted.

<S820>
When the frequency detection circuit 410 cannot properly detect the frequency of the power supply voltage (N in S830), the control circuit 60 turns on the switch 610 and changes the dummy resistor 70 from the non-conductive state to the conductive state (S820).

<S830A to S840>
After S820, the control circuit 60 observes whether the frequency detection circuit 410 has properly detected the frequency of the power supply voltage applied to the input terminals 10 and 11 (S830A). When the frequency detection circuit 410 cannot properly detect the frequency of the power supply voltage (N in S830A), the control circuit 60 sets the frequency a predetermined number of times (for example, 10 times every 0.5 seconds). Observation of the frequency detection state in the detection circuit 410 is repeated (retry). If the frequency detection state of the frequency detection circuit 410 by the control circuit 60 has not been observed a predetermined number of times (10 times) (N in S840), the frequency detection is repeated (return to S830A). .

<S850>
When observation of the frequency detection state in the frequency detection circuit 410 by the control circuit 60 has been executed a predetermined number of times (10 times) (Y in S840), the frequency of the power supply voltage is set to a predetermined fixed frequency. Deemed (S850). This process is the same as the process of S850 of the first embodiment.

<S860>
When the frequency detection circuit 410 can appropriately detect the frequency of the power supply voltage (Y in S830A) or when the frequency of the power supply voltage is regarded as a fixed frequency (S850), the control circuit 60 turns off the switch 610 and sets the dummy The resistor 70 is switched from the conductive state to the non-conductive state (S860).

<S861>
After detecting the frequency of the power supply voltage in the process of S830, S830A, or S850 or considering it as a specific frequency, the control circuit 60 returns the load of the functional circuit to the normal state (S861). In this way, the frequency detection process ends (S870).

  As described above, the frequency of the power supply voltage connected to the input terminals 10 and 11 is detected by the power supply apparatus having the configuration as described above. That is, the power supply device of this embodiment has the following characteristics.

  In the power supply device having the above-described configuration, the control unit (control circuit 60) is configured to be controllable so that the functional circuit has a maximum load when the frequency detection unit (410) performs frequency detection. It is characterized by.

  According to the voltage supply device having the above configuration, the load can be further increased during the period in which the frequency of the AC voltage is detected, thereby further increasing the voltage ripple observed by the frequency detection circuit 410. Therefore, frequency detection can be further facilitated.

<5. Supplementary items>
The specific description of each embodiment of the present invention has been given above. The above description is merely an embodiment, and the scope of the present invention is not limited to this embodiment, but should be broadly interpreted to the extent that a person skilled in the art can grasp.

  In the above embodiment, the fixed frequency in S850 may be set in advance by the user, or the frequency detected last time may be used.

  Further, the frequency detected by the frequency detection process is not necessarily 50 Hz or 60 Hz but may be another frequency.

  Further, the dummy resistor 70 may be configured not only by a resistance element but also by a combination with another element.

  The present invention is suitably applied as a power supply device in an electronic device to which power supply voltages having a plurality of types of frequencies are input.

DESCRIPTION OF SYMBOLS 10 ... Input terminal 20 ... Output terminal 30 ... Next side circuit 40 ... Next side circuit 50 ... Transformer 60 ... Control circuit 70 ... Dummy resistor 410 ... Frequency detection circuit 610 ... Switch

Claims (3)

A voltage supply device configured to convert an AC voltage input from an input terminal into a predetermined DC voltage and output from the output terminal to a functional circuit,
A frequency detector configured to detect the frequency of the AC voltage based on the ripple of the AC voltage;
A dummy resistor configured to increase a load resistance of the functional circuit connected to the output terminal;
A control unit capable of controlling the dummy resistor to be in a conductive state when the frequency detection unit performs frequency detection and to be in a non-conductive state when the functional circuit performs a normal operation. A voltage supply device. A primary circuit connected to the input terminal;
A secondary side circuit connected to the output terminal and electrically connected to the primary side circuit via a transformer,
The voltage supply device according to claim 1, wherein the frequency detection unit is arranged in the secondary side circuit. The said control part is comprised so that control is possible so that the said functional circuit may become a maximum load, when performing the detection of a frequency in the said frequency detection part. The Claim 1 or Claim 2 characterized by the above-mentioned. Voltage supply device.

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