JP2012161121A - Power supply device and heat source machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multiple output power supply device that can execute a power saving mode using a minimum possible power consumption within an allowable range of output voltage without requiring an additional constant voltage control circuit.SOLUTION: The power supply device having an output terminal 5 with a constant voltage control circuit 18 on an output side of a power transformer 2 and an output terminal 4 without any constant voltage control circuit includes a normal operation mode and a power saving mode in which output voltages at the output terminals 4 and 5 are reduced, and in the power saving mode, monitors the output voltage at the output terminal 4 without the constant voltage control circuit 18 by means of a microcomputer 1 and controls an input side of the power transformer 2 on condition that the output voltage does not fall below an allowable voltage.

Description

  The present invention relates to a power supply device and a heat source device. More specifically, the present invention relates to a multi-output power supply device used in a heat source device with a hot water heating function for supplying hot water to a hot water heating terminal, and only one output is controlled at a constant voltage. The present invention relates to a power supply device.

  Conventionally, a multi-output switching power supply device is generally used as a power supply device mounted on a heat source device such as a hot water supply device.

  FIG. 4 shows an example of a circuit configuration of a power supply device used for a power supply of a hot water supply device having a bath reheating function. As is well known, the power supply device shown in the figure has DC power obtained by rectifying AC power supplied from a commercial power source a by a diode bridge circuit b and smoothing by a smoothing capacitor c in series with a power transformer d. By switching (ON / OFF) the switching element at high speed, AC power generated on the output side (secondary side) of the power transformer d is rectified by a diode f and output as DC power.

  In the power supply device shown in FIG. 4, the DC power generated on the output side of the power transformer d in this way is supplied with a plurality of output terminals (in the illustrated example, A constant voltage control circuit (for example, a shunt) is designed to obtain a constant voltage of 15V output on a power supply line (15V line) provided with an output terminal of 15V output. Regulator) g. In the figure, symbol h indicates a switching IC that switches the switching element e, and symbol i indicates a photocoupler that cuts off a feedback signal applied to the switching ICh.

  By the way, in a hot water supply apparatus using such a power supply device, for example, a standby state in which combustion is stopped due to the hot water tap being closed while the operation switch of the remote controller is on is fixed for a certain time (for example, 15 In order to reduce the power consumption in the hot water supply device when certain conditions such as continuing) are satisfied, a device with a power saving mode that performs control to lower the output voltage of the power supply device has been proposed. (For example, refer to Patent Document 1).

  In the power supply device shown in FIG. 4, in the power saving mode, the voltage of the reference terminal of the shunt regulator g is varied while the voltage of the 15V output is monitored by the microcomputer j to lower the voltage of the 15V line.

JP 2002-101463 A

  However, such a conventional power supply apparatus has the following problems, and improvements have been desired.

  That is, some hot water supply devices using this type of power supply device use a 25 V output as a power supply for a communication circuit with a hot water heating terminal, and therefore, in a hot water supply device equipped with such a communication circuit, the power saving mode is set. Although it is desired to provide a power supply device equipped with the power supply device, since the constant voltage control circuit is not provided on the 25V output side of the power supply device shown in FIG. 4, if the output voltage on the 15V output side is too low in the power saving mode, 25V The output voltage on the output side may fall below the allowable voltage.

  In this regard, it is conceivable to provide a constant voltage control circuit on the 25V output side as well, but with such a configuration, the number of parts increases, which increases the board size and hinders downsizing of the power supply device. In addition, there is a problem in that the manufacturing cost increases.

  The present invention has been made in view of such a problem, and an object of the present invention is to allow an output voltage range that is allowed without adding a constant voltage control circuit in a multi-output power supply device. It is a main object of the present invention to provide a power supply apparatus that can execute a power saving mode that consumes as little power as possible. It is another object of the present invention to provide a heat source device that can appropriately communicate with a hot water heating terminal even in the power saving mode by using such a power supply device.

  In order to achieve the above object, a power supply apparatus according to claim 1 of the present invention includes a plurality of output terminals on the output side of the power transformer, and a constant voltage control circuit is included in one of the output terminals. In the power supply device, a normal operation mode and a power saving mode for dropping the output voltage of each output terminal are provided, and an output terminal that does not include the constant voltage control circuit in the power saving mode is provided. Control means configured to be able to monitor the output voltage, and in the power saving mode, the control means monitors the output voltage of the output terminal not provided with the constant voltage control circuit. The input side of the power transformer is controlled within a range that does not fall below the allowable voltage.

  That is, in the invention according to claim 1, in the power saving mode, the control means monitors the output voltage of the output terminal not provided with the constant voltage control circuit, and the output voltage does not fall below the allowable voltage. Since the input side of the power transformer is controlled, the output voltage of the output terminal not provided with the constant voltage control circuit can be lowered to the allowable voltage. For this reason, an output terminal without a constant voltage control circuit can execute a power saving mode without causing an output voltage shortage, and an output terminal without a constant voltage control circuit is effectively used in the power saving mode. However, a high power saving effect can be obtained.

  A power supply device according to claim 2 of the present invention is the power supply device according to claim 1, wherein a smoothing capacitor is provided at an output terminal provided with the constant voltage control circuit, and the control means includes: In the power saving mode, the control target voltage of the constant voltage control circuit is set to a first control target voltage set for the normal mode and a second control target voltage set for the power saving mode. The output obtained by alternately switching is smoothed by the smoothing capacitor and output as an output voltage.

  That is, in the invention according to claim 2, in the power saving mode, the first control target voltage set for the normal mode and the power saving mode are set as the control target voltage of the constant voltage control circuit. Since the pulse waveform voltage obtained by alternately switching the two control target voltages of the second control target voltage is smoothed to obtain the output voltage of the output terminal provided with the constant voltage control circuit, the first control By adjusting the timing for switching between the target voltage and the second control target voltage by the control means, the voltage output from the output terminal provided with the constant voltage control circuit in the power saving mode can be arbitrarily set.

  According to a third aspect of the present invention, there is provided the power supply device according to the first or second aspect, wherein an output terminal not provided with the constant voltage control circuit is an output of the power transformer via a three-terminal regulator. And switching means for short-circuiting the input / output terminals of the three-terminal regulator in the power saving mode.

  That is, in the invention according to claim 3, since the input / output terminals of the three-terminal regulator are short-circuited by the switch means in the power saving mode, it is avoided that power is consumed by the three-terminal regulator in the power saving mode. In addition, since the voltage on the output side of the power transformer can be lowered, the power consumption can be further reduced.

  The power supply apparatus according to claim 4 of the present invention is configured such that the control means can monitor the output voltage of the output terminal provided with the constant voltage control circuit in the power saving mode. It is characterized by.

  That is, in the invention according to claim 4, since the control means can also monitor the output voltage of the output terminal provided with the constant voltage control circuit in the power saving mode, the output voltage of the output terminal is It is possible to monitor whether the voltage falls below the allowable voltage.

  A heat source machine according to claim 5 of the present invention is a heat source machine with a hot water heating function provided with the power supply device according to any one of claims 1 to 4, and includes the constant voltage control circuit. The output terminal is a power supply terminal for the control circuit of the heat source machine, and the output terminal not equipped with the constant voltage control circuit is used as a power supply terminal for a communication circuit with the hot water heating terminal of the heat source machine. And

  That is, in the invention according to claim 5 of the present invention, the power supply device of the present invention is used for the power supply device of the heat source unit with the hot water heating function, and the output terminal not provided with the constant voltage control circuit in the power supply device is the hot water heating device. Since it is used as a power supply terminal for the communication circuit with the terminal, the communication circuit with the hot water heating terminal can be normally operated even in the power saving mode, and the communication between the heat source device and the hot water heating terminal can be appropriately performed. .

  According to the present invention, in the power saving mode, the output voltage of the output terminal not provided with the constant voltage control circuit can be lowered to the lower limit within a range not lower than the allowable voltage. An output terminal not provided with a constant voltage control circuit can be used effectively, and a high power saving effect can be obtained.

  Thus, it is possible to provide a heat source device that can normally operate the communication circuit with the hot water heating terminal even in the power saving mode and can appropriately communicate with the hot water heating terminal.

It is a circuit block diagram which shows an example of the power supply device which concerns on this invention. It is explanatory drawing which shows the power saving effect of the power supply device. It is a circuit block diagram which shows an example of other embodiment of the power supply device. It is a schematic block diagram which shows an example of the conventional power supply device.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Embodiment 1
A power supply device according to the present invention is a switching power supply device used for the power supply of a heat source device such as a hot water supply device having a hot water heating function, and is configured to be compatible with a normal operation mode and a power saving mode of the hot water supply device. By the control according to 1, the normal operation mode in which the voltage is output from the output terminal in the normal operation and the power saving mode in which the output voltage of the output terminal is lowered and output from the normal operation can be switched and used. Yes.

  FIG. 1 illustrates the output side (secondary side) of the power transformer 2 of the switching power supply having such a configuration.

  Here, since the configuration on the input side (primary side) of the power transformer 2 in the switching power supply device is well known, detailed description thereof will be omitted, but the input side of the power transformer 2 has AC power supplied from a commercial power source. A rectifying circuit for smoothing the rectified power, a smoothing circuit for smoothing the rectified power, a coil on the input side of the power transformer 2 to which the smoothed DC power is input, and a coil connected to the coil in series with the coil on the input side A switching element that switches electric power at high speed and a switching control circuit that controls switching by the switching element are provided as main parts.

  The switching control circuit is a control circuit that performs PWM control (Pulse Width Modulation) on switching elements such as transistors and FETs. The switching control circuit turns on / off the switching elements so that a desired voltage is obtained in the coil on the output side of the power transformer 2. The duty ratio of the control pulse to be turned off is set. The switching control circuit performs feedback control based on a feedback voltage given from the output side of the power transformer 2 so that the voltage on the output side of the power transformer 2 becomes a desired voltage. The feedback voltage for feedback is insulated from the output side of the power transformer 2 via the photocoupler 3, and a photodiode of the photocoupler 3 is shown in FIG. 1.

  Next, the output side of the power transformer 2 will be described. As shown in FIG. 1, this switching power supply device has an output terminal 4 (hereinafter referred to as “25V output terminal”) 4 having a nominal output of 25 V DC and an output having a nominal output of 15 V DC on the output side of the power transformer 2. A multi-output power supply device having two output terminals 5 (hereinafter referred to as “15V output terminal”) 5 is configured.

  The 25V output terminal 4 is provided in an output circuit having a diode 6, electrolytic capacitors 7 and 8 and a three-terminal regulator 9 as main parts, and the power generated in the coil on the output side of the power transformer 2 passes through this output circuit. Can be output from the 25 V output terminal 4. Here, although the nominal output of the 25V output terminal 4 is set to 25V DC, the actual output voltage in the normal operation mode (non-power-saving mode) due to variations in parts such as the power transformer 2. (Actual output voltage) is set to be slightly higher than the nominal output, for example, DC 29V (see the actual output voltage in the non-power-saving mode in FIG. 2).

  And in this embodiment, this 25V output terminal 4 is the said hot water supply apparatus in the hot water supply apparatus (heat source machine with a hot water heating function) provided with the function which supplies warm water to a hot water heating terminal like a hot water heating apparatus, for example. Is used as a power supply terminal for a communication circuit provided for communication with the hot water heating terminal.

  On the other hand, the 15V output terminal 5 is provided in an output circuit including the diode 10 and the electrolytic capacitors 11 and 12 as main parts. It can output from the terminal 5. The 15V output terminal 5 is provided with a constant voltage control circuit 18 that performs constant voltage control. Therefore, for this 15V output terminal 5, the actual output voltage in the normal operation mode (non-power saving mode) is set to the same DC 15V as the nominal output (the actual output voltage in the non-power saving mode in FIG. reference).

  The constant voltage control circuit 18 includes a shunt regulator 13 and voltage dividing resistors 14 to 17 for setting a voltage input to the reference terminal of the shunt regulator 13 as main parts. The voltage dividing resistors 14 to 17 are arranged in series between the power line of the 15V output terminal 5 and the ground, and the voltage divided by the resistors 14 and 15 and the resistors 16 and 17 is the shunt regulator 13. Input to the reference terminal.

  In this embodiment, the FET 20 is connected to both ends of the ground-side resistor 17, and the resistor 17 can be short-circuited by turning on the FET 20. That is, the voltage dividing ratio of the voltage dividing resistor of the shunt regulator 13 can be changed by short-circuiting the resistor 17, thereby switching the control target voltage of the shunt regulator 13 (in other words, the first control target voltage). And the second control target voltage can be switched). A transistor 21 controlled by the microcomputer 1 is connected to the control terminal of the FET 20, and the FET 20 is turned on by turning off the transistor 21.

  In this embodiment, the control target voltage when the resistor 17 is short-circuited is set to be the same as the nominal output of the 15V output terminal 5 (that is, the output voltage in the normal operation mode), while the resistor The control target voltage when 17 is not short-circuited is set to a lower limit value (or a nearby value not lower than the lower limit value) of the voltage allowed as the output voltage of the 15V output terminal 5 in the power saving mode. Specifically, the lower limit value of this voltage is set to DC 9.3 V, for example, according to a specific example shown in FIG. 2 described later, and each resistance value of the voltage dividing resistors 14 to 17 satisfies this condition. To be determined. Note that the control target voltage set in conjunction with this lower limit value is used in the power saving mode, as will be described later.

  In addition, the photodiode of the above-described photocoupler 3 is connected to the power line of the 15V output terminal 5 so that the voltage of the power line is fed back to the switching control circuit.

  The 15V output terminal 5 is a power source for a hot water supply device control circuit (for example, a power source for driving a relay), a power source to be supplied to a remote controller for remote control of the hot water supply device connected to the hot water supply device, and Is used as a power supply terminal of a power supply for a circuit that generates a power supply for a microcomputer mounted on the hot water supply apparatus.

  The microcomputer 1 is a control means for switching the output voltages of the output terminals 4 and 5 corresponding to the operation mode (normal operation mode and power saving mode) of the hot water supply apparatus. As shown in FIG. 1, it is connected to the 15V output terminal 4 and the 25V output terminal 5 so that the output voltage of each of the output terminals 4 and 5 can be monitored.

  The microcomputer 1 is also connected to the base terminal of the transistor 21 and is configured to control on / off of the transistor 21. Specifically, the microcomputer 1 can supply a pulse signal to the transistor 21, and is configured to control the transistor 21 by this pulse signal.

Next, the operation of the power supply apparatus configured as described above will be described with reference to FIG.
FIG. 2 is an explanatory diagram showing a specific example of the power saving effect of the power supply device according to the present invention. In FIG. 2, in the power saving mode, the voltage (allowable voltage) allowed as the output voltage of the 15V output terminal 5 is in the range of DC 9.3V to 15.7V, and the output voltage of the 25V output terminal 4 Is assumed to be in the range of DC 20V to 35V. The load current is 70 mA for the 15 V output terminal 5 and 40 mA for the 25 V output terminal 4.

  Under such conditions, when the microcomputer 1 selects the normal operation mode, the actual output voltage of the 15V output terminal 5 is 15V and the actual output voltage of the 25V output terminal 4 is 29V as described above. Therefore, the power consumption at this time is 2.21 W. In this normal operation mode, the microcomputer 1 does not supply a pulse signal to be described later to the transistor 21, turns off the transistor 21, and sets the control target voltage of the shunt regulator 13 to DC 15V. Yes.

  In the conventional power saving mode, since the microcomputer 1 cannot control the output voltage of the 25V output terminal 4, the 15V output terminal 5 prevents the output voltage of the 25V output terminal 4 from falling below the lower limit value (DC20V) of the allowable voltage. Since the actual output voltage is set to 13 V with a margin, for example, as shown in FIG. 2B, the power consumption is 1.87 W. That is, the power consumption is only reduced by 15% compared to the normal operation mode.

  On the other hand, in the power supply device shown in the present embodiment, the microcomputer 1 is connected to the 25V output terminal 4 and can monitor the output voltage of the output terminal 4 in the power saving mode. While the output voltage is monitored by the microcomputer 1, the power supply transformer 2 is within a range in which the output voltage does not fall below the lower limit value (DC20V) of the allowable voltage of the 25V output terminal 4 (preferably, the lower limit value is DC20V). Control the input side of.

  Specifically, this control is performed by alternately switching the control target voltage (DC 15 V and DC 9.3 V) of the shunt regulator 13. More specifically, the microcomputer 1 gives a pulse signal to the transistor 21 and turns on / off the transistor 21 and the FET 20 according to the pulse signal. As a result, a voltage between DC 15V and 9.3V is smoothed by the electrolytic capacitors 11 and 12 and output from the 15V output terminal 5 to the power line of the 15V output terminal 5. Therefore, by varying the duty ratio of the pulse signal applied to the transistor 21 at this time, the output voltage of the 15V output terminal 5 provided with the constant voltage control circuit 18 can be controlled, and the output of the 15V output terminal 5 can be controlled. With this change, the output voltage of the 25V output terminal 4 also decreases.

  In this way, when the output voltage of the output terminal 4 is lowered to the lower limit value (DC 20 V) of the allowable voltage while the output voltage of the 25 V output terminal 4 is monitored by the microcomputer 1, the voltage of the 15V output terminal 5 at that time Therefore, the power consumption is 1.605 W, and the power consumption can be reduced by 27% compared to the normal operation mode (see FIG. 2C).

  Thus, according to the present invention, in the power saving mode, the output voltage of the 25V output terminal 4 that is not provided with the constant voltage control circuit can be lowered to the lower limit value within a range that does not fall below the allowable voltage. Even in the power saving mode, the 25V output terminal 4 can be used effectively, and a high power saving effect can be obtained. Therefore, even in the power saving mode, the communication circuit with the heating terminal connected to the output terminal 4 can be operated normally, and communication between the heat source unit and the hot water heating terminal can be appropriately performed.

Embodiment 2
Next, a second embodiment of the present invention will be described with reference to FIG.
The power supply device shown in FIG. 3 shows a modified example of the power supply device shown in the first embodiment. Specifically, the power supply device shown in the first embodiment has an input / output terminal of a three-terminal regulator 9. The switch means 25 which can short-circuit between is added. Since other configurations are the same as those in the first embodiment, the same reference numerals are given to portions having the same configurations, and the description thereof is omitted.

  The switch means 25 is connected to the microcomputer 1 and is configured to short-circuit the input / output terminals of the three-terminal regulator 9 under the control of the microcomputer 1 in the power saving mode. Specifically, as the switch means 25, for example, a transistor controlled by the microcomputer 1 or a relay contact is used.

  Here, such a switch means 25 is provided in the power supply device shown in the first embodiment described above in which the output voltage of the 25V output terminal 4 is set to the lower limit value of the allowable voltage (or its neighborhood value) in the power saving mode. ), The voltage at the input terminal of the three-terminal regulator 9 is lowered, and the three-terminal regulator 9 may not be able to output the target voltage. In that case, since there is a voltage drop of the input / output voltage difference in the three-terminal regulator 9, the voltage on the output side of the power transformer 2 must be set higher, and as a result, the 15V output terminal side This is because there is a risk that the power saving effect will be impaired.

  FIG. 2D shows a specific example of power consumption when the second embodiment is applied to the power supply device shown in the first embodiment. In this case, the actual output voltage of the 15 V output terminal 5 is set to, for example, 0. It can be lowered by 5V, and the power consumption is 1.57W. That is, the power consumption can be reduced by 2% compared to the power supply device of the first embodiment and 29% compared to the normal operation mode, and the power saving effect can be further enhanced.

  The above-described embodiments show preferred embodiments of the present invention, and the present invention is not limited to these, and various design changes can be made within the scope of the invention.

  For example, in the above-described embodiment, the output terminal provided on the output side of the power transformer 2 has two outputs of DC25V and DC15V. However, two or more output terminals are provided on the output side of the power transformer 2. It may be.

  In the above-described embodiment, the configuration in which the microcomputer 1 and the 15V output terminal 5 are connected so that the microcomputer 1 can also monitor the output voltage of the 15V output terminal 5 has been described. Since the microcomputer 1 does not have to monitor the output voltage of the 15V output terminal 5 in the power mode, the microcomputer 1 and the 15V output terminal 5 may not be connected.

  In the above-described embodiment, although not particularly shown, when the hot water supply device shifts from the normal operation mode to the power saving mode, for example, the hot water tap is closed while the operation switch of the remote control is on. For example, the standby state in which combustion is stopped continues for a certain period of time, but the conditions for shifting from the normal operation mode to the power saving mode can be set as appropriate.

  In the above-described embodiment, the case where the power supply device is used in a heat source device such as a hot water supply device has been described. However, the power supply device according to the present invention can be used as a power supply for devices other than the hot water supply device. It is.

1 Microcomputer (control means)
2 Power transformer 3 Photocoupler 25 25V output terminal (output terminal without constant voltage control circuit)
5 15V output terminal (output terminal equipped with constant voltage control circuit)
9 Three-terminal regulator 11, 12 Electrolytic capacitor (smoothing capacitor)
13 shunt regulator 14-17 voltage dividing resistor 18 constant voltage control circuit 25 switch means

Claims (5)

In the power supply apparatus having a plurality of output terminals on the output side of the power transformer and having a constant voltage control circuit on one of the output terminals,
A normal operation mode and a power saving mode for dropping the output voltage of each output terminal are provided, and the output voltage of the output terminal not equipped with the constant voltage control circuit can be monitored in the power saving mode Controlled control means,
In the power saving mode, the control means controls the input side of the power transformer in a range in which the output voltage does not fall below an allowable voltage while monitoring the output voltage of an output terminal not provided with the constant voltage control circuit. A power supply device characterized by that. A smoothing capacitor is provided at an output terminal provided with the constant voltage control circuit,
The control means uses a first control target voltage set for the normal mode and a second control set for the power saving mode as the control target voltage of the constant voltage control circuit in the power saving mode. 2. The power supply device according to claim 1, wherein an output obtained by alternately switching the target voltage is smoothed by the smoothing capacitor and output as an output voltage. An output terminal not equipped with the constant voltage control circuit is connected to the output side of the power transformer via a three-terminal regulator,
3. The power supply device according to claim 1, further comprising switch means for short-circuiting the input / output terminals of the three-terminal regulator in the power saving mode.   The said control means is comprised so that the output voltage of the output terminal with which the said constant voltage control circuit was provided can also be monitored at the time of the said power saving mode. Power supply. A heat source machine with a hot water heating function provided with the power supply device according to any one of claims 1 to 4,
The output terminal provided with the constant voltage control circuit is a power supply terminal for the control circuit of the heat source machine, and the output terminal not provided with the constant voltage control circuit is a power supply for a communication circuit with the hot water heating terminal of the heat source machine A heat source machine that is used as a terminal.

Images