JP3202044B2 - Power supply - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply for equipment such as a jar, a rice cooker, an iron, and a vacuum cleaner, and to a power supply in which an electronic circuit used in the equipment is not insulated from a commercial power supply. Is the thing

[0002]

2. Description of the Related Art In recent years, electric appliances used in homes have become more common with electronic circuits including active elements. When an electronic circuit is mounted on a device, its configuration generally includes a power supply circuit and other electronic circuits.
Hereinafter, for convenience of description, the commercial power supply will be referred to as a primary circuit. Hereinafter, an example of the power supply of the above-described conventional primary circuit will be described with reference to FIG. 1 is a commercial AC power supply,
Reference numeral 20 denotes an automatic transformer for adjusting the voltage of the commercial AC power supply 1 to an appropriate level. 21 is a rectifier, 22 is a capacitor, and 10 is an electronic circuit serving as a load.

The operation of the conventional power supply circuit thus configured will be described. The AC voltage of the commercial AC power supply 1 is dropped by the auto transformer 20. The dropped AC voltage is rectified by the rectifier 21 and then the capacitor
It is smoothed at 22 and converted to a DC voltage. The DC voltage obtained at this time is determined by the voltage of the terminal output of the auto transformer 20.

[0004]

However, since the power supply circuit having the above configuration uses a transformer,
There are problems such as a large amount of material used, high cost, low cost, heavy, large, inefficient, and large heat generation.

The present invention is intended to solve the problems of the conventional method and to realize a power supply device which can be used more easily. Construct a power supply that charges the capacitor until the voltage reaches a certain value, stops power supply when the voltage exceeds a certain value, and automatically prevents an increase in power consumption when the commercial power supply voltage drops below a certain value. It is an object of the present invention to provide a power supply device capable of performing the following. It is still another object of the present invention to provide a power supply device capable of automatically stopping power supply when the commercial power supply voltage drops by a certain value or more, and preventing an increase in power consumption caused when the commercial power supply voltage drops excessively. Things.

[0006]

[0007]

[MEANS FOR SOLVING THE PROBLEMS] To achieve the above object
The power supply device of the present invention is a rectifier circuit for rectifying commercial AC power.
Path and a first for turning on and off a rectified output by the rectifying circuit.
And the output of the first switch circuit.
And supply DC power to the load by charging.
A rectifier output voltage by the rectifier circuit.
And generates a reference voltage of
A first method for changing an operation state according to a change in a rectified output voltage.
And a first reference voltage generating circuit.
Based on the operation change, the first switch circuit
A first switch control circuit for controlling on / off of the rectified output.
And a regulating circuit proportional to the peak voltage of the commercial AC power supply.
By holding the output voltage for a certain period of time,
A voltage of the commercial AC power supply with respect to a predetermined voltage based on
An AC voltage detection circuit for detecting fluctuations, and the AC voltage detection circuit;
Circuit for detecting voltage fluctuation of the commercial AC power supply.
A third switch control circuit that turns on and off based on the result;
Obtained from the on / off operation of the third switch control circuit.
Of the commercial AC power supply detected by the AC voltage detection circuit.
Operation of the first reference voltage generation circuit according to a voltage change
A second switch circuit for controlling the change.
The voltage detection circuit detects the voltage fluctuation of the commercial AC power supply as
While detecting a drop with respect to a predetermined voltage, the second switch
The circuit sets the first reference voltage to 0, thereby
Irrespective of a change in the rectified output voltage, the first reference voltage
While the live circuit is in operation, the first switch control circuit
Maintain the off state of the first switch circuit by a path
It is configured as follows.

Further, the power supply device of the present invention is a commercial AC power supply.
A rectifier circuit for rectifying a source, and a rectified output by the rectifier circuit
A first switch circuit for turning on and off the first switch.
The output of the switch circuit is charged, and the DC power resulting from the charging is
Capacitor to supply load and rectification output by the rectifier circuit
Generating a first reference voltage for the input voltage;
Operating state in accordance with the change of the rectified output voltage with respect to the reference voltage.
A first reference voltage generating circuit for changing the state,
From the first reference voltage to the rectified output voltage
Generating a second, lower reference voltage, with respect to the second reference voltage;
The operating state changes according to the change in the rectified output voltage.
A second reference voltage generating circuit for generating the first reference voltage;
Change in operation of the raw circuit and the second reference voltage generation circuit.
The rectified output by the first switch circuit based on
A first switch control circuit for controlling on / off of the
The rectified output voltage in proportion to the peak voltage of the commercial AC power supply
By holding for a certain time, based on the voltage,
Detects a voltage fluctuation of the commercial AC power supply with respect to a predetermined voltage
AC voltage detection circuit, and the AC voltage detection circuit
Based on the detection result for the voltage fluctuation of the commercial AC power supply
A third switch control circuit for turning on and off
The AC obtained from the on / off operation of the switch control circuit
Voltage fluctuation of the commercial AC power supply detected by the voltage detection circuit.
Responsively controls a change in operation of the first reference voltage generation circuit.
A second switch circuit for performing the AC voltage detection circuit.
Path to the predetermined voltage as a voltage fluctuation of the commercial AC power supply.
During the detection of the falling, the second switch circuit
Switching the first reference voltage to the second reference voltage;
Corresponds to the operation period of the second reference voltage generation circuit.
Then, the first switch control circuit operates the first switch.
The period of the off state of the switch circuit is set to the AC voltage detection circuit.
Is detecting a rise of the commercial AC power supply with respect to a predetermined voltage.
It is configured to be longer than the case .

Further, the power supply device of the present invention is a commercial AC power supply.
A rectifier circuit for rectifying a source, and a rectified output by the rectifier circuit
A first switch circuit for turning on and off the first switch.
The output of the switch circuit is charged, and the DC power resulting from the charging is
Capacitor to supply load and rectification output by the rectifier circuit
Generating a first reference voltage for the input voltage;
Operating state in accordance with the change of the rectified output voltage with respect to the reference voltage.
A first reference voltage generating circuit for changing the state,
Based on a change in operation of the reference voltage generation circuit, the first switch
A control circuit for controlling on / off of the rectified output by a switch circuit;
1 switch control circuit and the peak power of the commercial AC power supply.
Holding the rectified output voltage proportional to the pressure for a certain period of time.
According to the voltage, based on the predetermined voltage
AC voltage detection circuit that detects voltage fluctuation of commercial AC power supply
And the power supply of the commercial AC power supply by the AC voltage detection circuit.
A third method of turning on / off based on a detection result for pressure fluctuation
A switch control circuit and the third switch control circuit.
The AC voltage detection circuit obtained from the
The first switch according to the voltage fluctuation of the commercial AC power supply.
A control circuit for controlling on / off of the rectified output by a switch circuit;
3. The switch circuit of claim 3, wherein the AC voltage detection circuit is
The voltage fluctuation of the commercial AC power
While the falling is detected, the third switch circuit turns on.
By holding and short-circuiting the first switch circuit.
Therefore, the first switch is independent of the change in the rectified output voltage.
The switch circuit is configured to maintain the off state .

[0010] Further, the power supply device of the present invention comprises a commercial AC power supply.
A rectifier circuit for rectifying a source, and a rectified output by the rectifier circuit
A first switch circuit for turning on and off the rectifier circuit;
Output from the first switch circuit for the rectified output
A first current limiting circuit for limiting a force current, and the rectifier circuit
From the first switch circuit to the rectified output by
The output current is larger than that by the first current limiting circuit.
A second current limiting circuit for limiting current, and the first switch.
The output of the switch circuit is charged, and the DC power resulting from the charging is loaded.
And a rectifier output by the rectifier circuit
Generating a first reference voltage with respect to the voltage;
Operating state according to the change of the rectified output voltage with respect to the voltage
A first reference voltage generating circuit for changing the
Based on a change in operation of the quasi-voltage generating circuit, the first switch
A first circuit for controlling on / off of the rectified output by a switch circuit.
Switch control circuit, and the peak voltage of the commercial AC power supply
To maintain the rectified output voltage in proportion to
And a quotient for a predetermined voltage based on the voltage.
AC voltage detection circuit for detecting voltage fluctuations of the AC power supply for
Voltage change of the commercial AC power supply by the AC voltage detection circuit
A third switch that turns on and off based on the detection result
Switch control circuit and on / off of the third switch control circuit.
Before the AC voltage detection circuit obtained from the
The first current control is performed in accordance with the voltage fluctuation of the commercial AC power supply.
Switching between the current limiting circuit and the second current limiting circuit.
Control the amount of output current from the switch circuit of the third
Switch circuit, wherein the AC voltage detection circuit is
As the voltage fluctuation of the commercial AC power supply,
During the detection of a fall, the third switch circuit keeps the ON operation.
The output from the first switch circuit.
Before the current is limited by the first current limiting circuit,
Switching to the limitation by the second current limiting circuit,
The current limit circuit to maintain the limit state.
Those were.

[0011]

[0012]

With the above arrangement, when the commercial AC voltage is higher than the predetermined voltage detected and set by the AC voltage detection circuit and the voltage rectified by the rectification circuit is equal to or lower than the first reference voltage, the first switch control circuit performs the operation. Short-circuit the first switch circuit,
The capacitor is charged with the current limited by the first current limiting circuit and power is supplied to the load. When the output voltage of the rectifier circuit exceeds the first reference voltage, the first switch control circuit opens the first switch circuit and stops energization. When the commercial AC voltage fluctuates and falls to a predetermined voltage detected and set by the AC voltage detection circuit, the third switch control circuit controls the second switch circuit and stops the operation of the first reference voltage generation circuit. This acts on the first switch control circuit to cut off the first switch circuit and stop supplying power to the capacitor and the load. In this way, a power supply device that can suppress power consumption to a certain value or less when the AC voltage decreases by a certain value or more can be realized.

Further, when the commercial AC voltage is higher than the voltage detected by the AC voltage detection circuit and the voltage rectified by the rectifier circuit is equal to or lower than the first reference voltage, the first switch control circuit controls the first switch. The circuit is short-circuited, the capacitor is charged with the current limited by the first current limiting circuit, and power is supplied to the load. When the output voltage of the rectifier circuit exceeds the first reference voltage, the first switch control circuit opens the first switch circuit and stops energization. When the commercial AC voltage decreases by a certain value and drops to a voltage detected by the AC voltage detection circuit, the third switch control circuit controls the second switch circuit and generates the second reference voltage from the first reference voltage generation circuit. The circuit is switched to a circuit, and power supply or stop by the first reference voltage generation circuit is performed by the second reference voltage generation circuit. In this way, it is possible to realize a power supply device capable of suppressing an increase in power supply to a capacitor and a load due to a decrease in AC voltage and suppressing power consumption to a certain value or less.

Further, when the AC voltage decreases by a certain value and is detected by the AC voltage detection circuit, the third switch control circuit
And cuts off the current flowing through the first current limiting circuit. As a result, when the commercial power supply voltage decreases, power supply to the capacitor and the load is stopped, and a power supply device capable of suppressing an increase in power consumption to a certain value or less can be realized.

Further, when the AC voltage decreases by a certain value and is detected by the AC voltage detection circuit, the third switch control circuit
The first current limiting circuit to the second
To the current limiter circuit. As a result, it is possible to realize a power supply device capable of suppressing an increase in the amount of power supplied to the capacitor and the load by reducing the current value when the commercial power supply voltage is reduced, and suppressing power consumption to a certain value or less.

[0016]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing a power supply circuit according to a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a commercial AC power supply, and 2 denotes a rectifier circuit connected to one terminal A of the commercial AC power supply 1. In this embodiment, the rectifier circuit is a positive half-wave rectifier circuit. Reference numeral 3 denotes a first current limiting circuit for limiting a current value passing through this line to a certain value or less, and includes diodes 3a and 3b and a resistor 3c. Reference numeral 4 denotes a first switch circuit for turning on / off the power supply to the output side. In this embodiment, a transistor is used. The first current limiting circuit 3 operates as follows. When the base current of the transistor 4 flows and the transistor 4 is turned on, a voltage of 0.6 V is generated between the base and the emitter, and a voltage of about 1.8 V is generated in the diodes 3a and 3b. Therefore, a voltage of 1.2 V is applied to the resistor 3c, and the current flowing through the resistor 3c is limited by the value of the resistor 3c.

Reference numeral 5 denotes a capacitor connected to the output terminal E side of the first switch circuit 4, from which a DC output voltage is obtained. Reference numeral 6 denotes a first reference voltage generating circuit for generating a first reference voltage.
Consists of a constant voltage diode 6a and a resistor 6b connected in series from the output terminal C of the rectifier circuit 2 to the other terminal B of the commercial power supply 1, and the voltage at the connection point D between the two is connected to a first reference voltage generating circuit. 6 output voltage. Reference numeral 7 denotes a first switch control circuit that receives the output of the first reference voltage generation circuit 6 and controls the first switch circuit 4. The first switch control circuit 7 includes resistors 7a and 7d and a transistor 7b. , 7
In the connection configuration, the collector of the transistor 7b is connected to the base of the transistor 7c and one end of the resistor 7a, and the other end of the resistor 7a is connected to a point C which is the output terminal of the rectifier circuit 2. , The emitters of the transistors 7b and 7c are connected to the terminal B of the commercial power supply.
It is connected to the. The base of the transistor 7b is connected to a point D which is the output terminal of the first reference voltage generating circuit 6, and the collector of the transistor 7c is connected to the base of the transistor 4 forming the first switch circuit via the resistor 7d. It is connected.

Reference numeral 8 denotes an output voltage detection circuit for detecting the DC voltage across the capacitor 5.
Is composed of a constant voltage diode 8a and a resistor 8b. The constant voltage diode 8a and the resistor 8b are connected in series.
, And the other end of the resistor 8b is connected to a terminal B of the commercial power supply, which is the same point as the negative terminal of the capacitor 5. A connection point F between the constant voltage diode 8a and the resistor 8b is an output terminal of the output voltage detection circuit 8, and is connected to the second switch control circuit 9. In the present embodiment, the second switch control circuit 9 is constituted by a transistor. The base of the second switch control circuit 9 is connected to the output terminal F of the output voltage detection circuit 8, and the collector is the collector of the transistor 7b of the first switch control circuit 7. Connected to
The emitter is connected to the terminal B of the commercial power supply. Reference numeral 10 denotes a load connected to both ends of the capacitor 5, which is usually an input of an electronic circuit or a constant voltage power supply circuit.

Next, the operation of the first embodiment will be described. The output voltage of the rectifier circuit 2 is changed from 0 to the first reference voltage generation circuit 6
, Which is the operating voltage of the constant voltage diode 6a
Until the reference voltage (hereinafter, simply referred to as a first reference voltage) is reached, the first reference voltage generation circuit 6 does not operate, and no voltage is generated between both terminals of the resistor 6b. Therefore, the transistor 7b is off, and the transistor 7c is turned on by supplying a bias current to the base by the resistor 7a. Therefore, a current flows through the base of the transistor constituting the first switch circuit 4 via the resistor 7d. As a result, the first switch circuit 4 is turned on, a current flows from the rectifier circuit 2 to the collector via the emitter of the first switch circuit 4, and the capacitor 5 is charged. The load connected to both ends of the capacitor 5 at the same time
10 is also powered.

In this case, the charging current of the capacitor 5 and the load
The current flowing through 10 becomes equal to or less than the value limited by the first current limiting circuit 3. That is, when the first switch circuit 4 is turned on, a current also flows through the diodes 3a and 3b connected in series at the same time, and a voltage of about 1.8 V is generated during this time. On the other hand, a voltage of about 0.6 V is generated between the base and the emitter of the transistor 4, and the resistor 3c has a diode 3a,
A voltage of about 1.2 V, which is the difference from the sum of 3b and 1.8 V, is applied. Therefore, by appropriately selecting the value of the resistor 3c, the current flowing through the resistor 3c, in other words, the first
The current flowing through the transistor constituting the switch circuit 4 is limited.

The output voltage of the rectifier circuit 2 rises and exceeds the first reference voltage, and the ON voltage between the base and the emitter of the transistor 7b constituting the first switch control circuit 7, approximately 0.
When the voltage exceeds 6 V, the transistor 7b turns on and a current flows to the collector through the resistor 7a. As a result, a voltage is generated in the resistor 7a, and the base-emitter voltage of the transistor 7c becomes almost 0 V,
Is turned off. When the transistor 7c is turned off, the first
The base current is no longer supplied to the transistors constituting the switch circuit 4, and the transistors are turned off. Therefore, no power is supplied to the capacitor 5 and the load 10.

When the output voltage of the rectifier circuit 2 rises and exceeds the peak voltage and falls again below the on-voltage of the transistor 7b constituting the first switch control circuit 7, the transistor 7b turns off and the transistor 7c turns on. . Therefore, the first switch circuit 4 is turned on, and the commercial power is supplied to the capacitor 5 and the load 10 again.

As described above, in this embodiment, the power supply to the capacitor and the load is turned on / off with the commercial power supply voltage at the first reference voltage. From the viewpoint of the AC cycle, The conduction angle is determined by the ratio of the voltage determined by the first reference voltage to the peak voltage of the AC power supply, and power is supplied to the capacitor and the load at this conduction angle. Since the first reference voltage is a constant voltage, the conduction angle increases when the voltage of the commercial AC power supply decreases. That is, the energization time becomes longer, and the power supply to the capacitor and the load increases as the power supply voltage decreases. Therefore, as the power supply voltage decreases, the capacitor 5
The voltage between both ends increases. This increase increases as the amount of decrease in the power supply voltage increases.

On the other hand, the output voltage detection circuit 8
The output voltage between both ends is monitored. While the voltage of the commercial AC power supply is high and the output voltage is lower than the operating voltage of the constant voltage diode 8a, no current flows through the resistor 8b, so that no voltage is generated at both ends. Therefore, the transistor constituting the second switch circuit 9 is off, and the first switch circuit 4 is continuously controlled by the first switch control circuit 7.

Now, when the voltage of the commercial AC power supply drops and the output voltage exceeds the operating voltage of the constant voltage diode 8a, this operating voltage is generated between both terminals of the constant voltage diode 8a, and at the same time, the resistor 8b The remaining voltage is generated between both terminals. If the voltage at both ends of the resistor 8b exceeds the base-emitter on-voltage of the transistor 9 constituting the second switch control circuit 9, the second switch control circuit 9
Are turned on, and the first switch control circuit 7 is operated prior to the first reference voltage generation circuit 6. Thus, the first switch circuit 4 is turned off, and the power supply to the capacitor 5 and the load 10 is stopped. In this way, by preventing the output voltage from rising above a certain level, it is possible to prevent the power supply to the capacitor and the load from increasing above a certain level even if the voltage of the commercial AC power supply drops below a certain level.

FIG. 2 is a circuit diagram showing a power supply circuit according to a second embodiment of the present invention. In FIG. 2, the same elements as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. 11
Is an AC voltage detection circuit for detecting the level of the AC voltage, and the AC voltage detection circuit 11 includes a constant voltage diode 11a, a resistor 11b, and a capacitor 11c. The constant voltage diode 11a and the resistor 11b are connected in series. The anode at the other end of the constant voltage diode 11a is connected to the terminal B of the commercial power supply at the same point as the negative terminal of the capacitor 5, and the other end of the resistor 11b is connected to the output terminal C of the rectifier circuit 2.
The resistor 11b and the capacitor 11c are connected in parallel.
The capacitor 11c can store a voltage proportional to the peak voltage of the commercial power supply for a certain period of time by its function.

A connection point G between the constant voltage diode 11a, the resistor 11b and the capacitor 11c is an output terminal of the AC voltage detection circuit 11, and is connected to the third switch control circuit 12. The third switch control circuit 12 includes a transistor 12a and a resistor 12b. The base of the transistor 12a is connected to the output terminal G of the AC voltage detection circuit 11, and the collector is connected to one end of the resistor 12b. Is connected as an output to the second switch circuit 13, the emitter is connected to the output terminal C of the rectifier circuit 2, and the other end of the resistor 6b is connected to the terminal B of the commercial power supply. Second switch circuit 13
Is constituted by a transistor in this embodiment, the base of which is connected to the output terminal H of the third switch control circuit 12, and the collector is connected to the constant voltage diode 6a of the first reference voltage generation circuit 6 and the resistor 6b. Connected to connection point D,
The emitter is connected to the output terminal C of the rectifier circuit 2.

Next, the operation of the second embodiment will be described. The output peak voltage of the rectifier circuit 2 is equal to the operating voltage of the constant voltage diode 11 a of the AC voltage detection circuit 11 and the third switch control circuit 12.
When the ON voltage of the transistor 12a is equal to or higher than the sum of about 0.6 V, the transistor 12a is turned on, a current flows through the resistor 12b, and the emitter-collector voltage of the transistor 12a becomes almost 0V. At this time, the second switch circuit 13 is turned off, and the first reference voltage generation circuit 6 creates the first reference voltage by the constant voltage diode 6a. Until the output voltage of the rectifier circuit 2 reaches from 0 to the first reference voltage which is the operating voltage of the constant voltage diode 6a constituting the first reference voltage generation circuit 6, the first reference voltage generation circuit 6 Does not work. That is, no voltage is generated between both terminals of the resistor 6b. Therefore, the transistor 7b is off, and the transistor 7c is turned on by supplying a bias current to the base by the resistor 7a. Therefore, a current flows through the transistor constituting the first switch circuit 4 to the base via the resistor 7d. As a result, the first switch circuit 4 is turned on, a current flows from the rectifier circuit 2 to the collector via the emitter of the first switch circuit 4, and the capacitor 5 is charged. At the same time, power is also supplied to the load 10 connected to both ends of the capacitor 5.

In this case, the charging current of the capacitor 5 and the load
The current flowing through 10 becomes equal to or less than the value limited by the first current limiting circuit 3. That is, when the first switch circuit 4 is turned on, a current also flows through the diodes 3a and 3b connected in series at the same time, and a voltage of about 1.8 V is generated during this time. On the other hand, a voltage of about 0.6 V is generated between the base and the emitter of the transistor 4, and the resistors 3c are connected to the diodes 3a and 3b.
A voltage of about 1.2 V, which is a difference from the voltage of 1.8 V of b, is applied.
Therefore, by appropriately selecting the value of the resistor 3c, the current flowing through the resistor 3c, in other words, the current flowing through the transistor forming the first switch circuit 4 is limited.

The output voltage of the rectifier circuit 2 rises and exceeds the first reference voltage, and the ON voltage between the base and the emitter of the transistor 7b constituting the first switch control circuit 7 is approximately 0.1.
When the voltage exceeds 6 V, the transistor 7b turns on and a current flows to the collector through the resistor 7a. As a result, a voltage is generated in the resistor 7a, and the base-emitter voltage of the transistor 7c becomes almost 0 V,
Is turned off. When the transistor 7c is turned off, the first
The base current is not supplied to the transistors constituting the switch circuit 4 of FIG. Therefore, no power is supplied to the capacitor 5 and the load 10.

When the output voltage of the rectifier circuit 2 rises and exceeds the peak voltage and falls again below the on-voltage of the transistor 7b constituting the first switch control circuit 7, the transistor 7b turns off and the transistor 7c turns on. . Therefore, the first switch circuit 4 is turned on, and the commercial power is supplied to the capacitor 5 and the load 10 again.

Next, the output peak voltage of the rectifier circuit 2 drops by a fixed value, and the operating voltage of the constant voltage diode 11a of the AC voltage detection circuit 11 and the transistor 12 of the second switch control circuit 12
When the ON voltage of a becomes equal to or less than the sum of about 0.6 V, the transistor 12a is turned off and no current flows through the resistor 12b. At this time, the resistor 12b turns on the transistor 13 as a bias resistor of the transistor of the second switch circuit 13, and the voltage between the emitter and the collector becomes almost 0V,
The current flows through the resistor 6b, and simultaneously turns on the transistor 7b of the first switch control circuit 7. As a result, the first switch circuit 4 is turned off. That is, when the commercial power supply voltage falls below the voltage detected by the AC voltage detection circuit 11, the first switch circuit 4 continues to be in the off state, and power supply to the capacitor 5 and the load 10 is stopped.

As described above, the power supply to the capacitor 5 and the load 10 is supplied to a certain voltage of the commercial power supply, that is, the first reference voltage when the commercial power supply voltage is high, and is supplied when the commercial power supply drops by a certain value or more. Perform the operation of stopping.
From the viewpoint of the conduction angle of the commercial AC frequency in the same manner as in the first embodiment, the operation of supplying power from 0 V of the commercial power supply to a constant voltage is performed when the commercial power supply voltage is high. The angle is short, and when the commercial power is low, the conduction angle is long. Therefore, when power is supplied to the capacitor 5 and the load 10 with a constant current, the amount of power supplied to the capacitor 5 and the load 10 increases as the commercial power supply voltage decreases. However, according to the present embodiment, when the AC voltage drops by a certain amount or more, it becomes possible to cut off the power supply to protect the power supply device.

FIG. 3 is a circuit diagram showing a power supply circuit according to a third embodiment of the present invention. In FIG. 3, the same elements as those in the first and second embodiments are denoted by the same reference numerals, and description thereof will be omitted. Reference numeral 14 denotes a second reference voltage generating circuit, which includes a constant voltage diode 14a and a resistor 6 of the first reference voltage generating circuit 6.
b, the anode of the constant voltage diode 14a is connected to the resistor 6b, and the cathode is a second switch circuit.
Connected to 13 collectors. Second switch circuit 13
In this case, the first reference voltage generator 6 and the second reference voltage generator 14 receive the output of the third switch control circuit 12 and
It works to switch between. The second reference voltage, which is the operating voltage of the constant voltage diode 14a constituting the second reference voltage generation circuit 14, is set to a value lower than the first reference voltage of the first reference voltage generation circuit 6. And

Next, the operation of the third embodiment will be described. The output peak voltage of the rectifier circuit 2 is equal to the operating voltage of the constant voltage diode 11 a of the AC voltage detection circuit 11 and the third switch control circuit 12.
When the ON voltage of the transistor 12a is equal to or higher than the sum of about 0.6 V, the transistor 12a is turned on, a current flows through the resistor 12b, and the emitter-collector voltage of the transistor 12a becomes almost 0V. At this time, the second switch circuit 13 is turned off, and the first reference voltage generating circuit 6 generates the first reference voltage by the sum of the respective operating voltages of the constant voltage diode 6a and the resistor 6b. Hereinafter, the operation of this embodiment is as described in the second embodiment.

Next, the output peak voltage of the rectifier circuit 2 is equal to the operating voltage of the constant voltage diode 11a of the AC voltage detection circuit 11 and the third peak voltage.
ON voltage of the transistor 12a of the switch control circuit 12 of FIG.
When the voltage drops below the sum of 0.6V, the transistor 1
2a turns off, and the transistor of the third switch circuit 13 turns on using the resistor 12b as a bias resistor. As a result, a current flows from the emitter / collector of the transistor 13 to the path of the constant voltage diode 14a and the resistor 6b, and the voltage between the emitter and collector of the transistor 13 becomes almost 0V. As a result, the constant voltage diode 14a and the resistor 6b are equivalently connected between the output terminal C of the rectifier circuit 2 and the terminal B of the commercial power supply, forming the second reference voltage generating circuit 14. Power is supplied to the capacitor 5 and the load 10 by the reference voltage of the second reference voltage generation circuit 14. As described above, since the operating voltage of the constant voltage diode 14a is lower than the operating voltage of the constant voltage diode 6a forming the first reference voltage, the conduction angle at the time of energization becomes small, and power supply to the capacitor 5 and the load 10 is performed. In addition, the power consumption of the power supply device itself is reduced.

FIG. 4 is a circuit diagram showing a power supply circuit according to a fourth embodiment of the present invention. In FIG. 4, the same elements as those in the first and second embodiments are denoted by the same reference numerals, and description thereof will be omitted. Reference numeral 15 denotes a third switch circuit. In this embodiment, a transistor is used, the base of which is connected to the output terminal H of the third switch control circuit 12, the emitter is connected to the output terminal C of the rectifier circuit 2, and the collector is the transistor of the first switch circuit 4. Connected to the base.

Next, the operation of the fourth embodiment will be described. When the output peak voltage of the rectifier circuit 2 is equal to or higher than the sum of the operating voltage of the constant voltage diode 11a of the AC voltage detection circuit and the ON voltage of the transistor 12a of the third switch control circuit 12, about 0.6 V, the transistor 12a is turned on. A current flows through the resistor 12b, and the voltage between the emitter and the collector of the transistor 12a becomes almost 0V. At this time, the third switch circuit 15 is turned off, and the power supply apparatus operates by the first current limiting circuit 3.

Next, the output peak voltage of the rectifier circuit 2 is approximately equal to the operating voltage of the constant voltage diode 11a of the AC voltage detection circuit and the ON voltage of the transistor 12a of the third switch control circuit 12.
When the voltage drops below the sum of 6 V, the transistor 12
a turns off, and the transistor of the third switch circuit 15 turns on using the resistor 12b as a bias resistor. As a result, the emitter and collector of the transistor of the third switch circuit 15 are connected to the collector and collector of the resistor 7d and the transistor 7c.
A current flows through the emitter, and the voltage between the emitter and the collector of the third switch circuit 15 becomes almost 0V. Thereby, the emitter of the transistor of the first switch circuit 4
The voltage between the collectors becomes 0 V, the first switch circuit 4 is cut off, and the power supply to the capacitor 5 and the load 10 is stopped.

FIG. 5 is a circuit diagram showing a power supply circuit according to a fifth embodiment of the present invention. In FIG. 5, the same elements as those of the first, second, third, and fourth embodiments are denoted by the same reference numerals,
Description is omitted. Reference numeral 16 denotes a second power supply limiting circuit, which is composed of a diode 3a and a resistor 3c.
In this case, the collector 15 is connected to the connection point between the diode 3b and the diode 3a.

Next, the operation of the fifth embodiment will be described. The output peak voltage of the rectifier circuit 2 is equal to the operating voltage of the constant voltage diode 11a of the AC voltage detection circuit 11 and the third switch control circuit.
When the ON voltage of the twelve transistors 12a is equal to or higher than the sum of about 0.6 V, the transistor 12a is turned on, a current flows through the resistor 12b, and the emitter-collector voltage of the transistor 12a becomes almost 0V. At this time, the third switch circuit 15
Is turned off, and the present power supply device is operated by the first current limiting circuit 3. At this time, the voltage applied to the resistor 3c is
A voltage of about 1.2 V, which is obtained by subtracting the base-emitter voltage of the first switch circuit 4 from the sum voltage of the diodes 3a and 3b, is applied. That is, in this case, the current flowing through the first switch circuit 4 is limited by the resistance value of the resistor 3c.
With this current value, power is supplied to the capacitor 5 and the load 10.

Next, the output peak voltage of the rectifier circuit 2 is equal to the operating voltage of the constant voltage diode 11a of the AC voltage detection circuit 11 and the third peak voltage.
ON voltage of the transistor 12a of the switch control circuit 12 of FIG.
When the voltage drops below the sum of 0.6V, the transistor 1
2a turns off, and the transistor of the third switch circuit 15 turns on using the resistor 12b as a bias resistor. As a result, a current flows from the emitter / collector of the transistor of the third switch circuit 15 through the diode 3a, the resistor 7d and the collector / emitter of the transistor 7c, and the voltage between the emitter and collector of the third switch circuit 15 becomes almost 0V. Become. Thus, a second current limiting circuit 16 is formed. At this time, the voltage applied to the resistor 3c is about 0.6 V obtained by subtracting the base-emitter ON voltage of the transistor constituting the first switch circuit 4 from the voltage of the diode 3a. Therefore, the current determined by the value of the resistor 3c, that is, the current determined by the second current limiting circuit 16 flows through the first switch circuit 4.

In the present embodiment, the voltage applied to the resistance value of the resistor 3c is equivalent to two diodes when the first current limiting circuit is used, and when the second current limiting circuit 16 is used. The second current limiting circuit
When 16 is used, the current passing through the first switch circuit 4 is half that when the first current limiting circuit 3 is used. As a matter of course, by changing the number of diodes 3a or 3b, a desired limiting current can be adjusted stepwise. As a result, it is possible to freely reduce power with respect to an increase in power when the commercial AC power supply voltage is reduced.

[0044]

As described above, according to the present invention, an easy-to-use power supply device can be realized without using a transformer. That is, as a first effect , by detecting the output voltage and controlling the energizing switch, a stable voltage can be supplied to the load even when the power supply voltage fluctuates, and the load is not destroyed. Further, a power supply device in which an element such as a transistor used is not broken can be realized.

As a second effect , by detecting a drop in the commercial AC power supply voltage, the action of the voltage serving as a reference for power supply to the capacitor and the load is stopped, and thereby the power supply is cut off and the first power supply is stopped. it is possible to obtain the same effect as the effect. As a third effect , a decrease in the commercial AC voltage is detected, and when the commercial AC voltage decreases by a certain value, the conduction angle of the power supply is reduced by changing the reference voltage of the switch control circuit. the increase in power consumption suppressed, it is possible to obtain the same effect as in the first effect.

[0046] As a fourth effect, to detect the decrease of the commercial AC voltage, by blocking the direct power supply switch when the commercial AC voltage drops a predetermined value, it is possible to obtain the same effect as in the first effect, As a fifth effect , the second effect can be realized by setting the value of the energizing current to zero.

[0047] Further, as a fifth effect of detecting a drop of the commercial AC voltage, the commercial AC voltage drops a predetermined value by reducing the current during power supply, to obtain the same effect as the first effect Can be.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a power supply device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a power supply device according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a power supply device according to a third embodiment of the present invention.

FIG. 4 is a block diagram showing a power supply device according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram showing a power supply device according to a fifth embodiment of the present invention.

FIG. 6 is a block diagram showing a conventional power supply device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Commercial AC power supply 2 Rectifier circuit 3 First current limiting circuit 4 First switch circuit 5 Capacitor 6 First reference voltage generation circuit 7 First switch control circuit 8 Output voltage detection circuit 9 Second switch control circuit 11 AC voltage detection circuit 12 Third switch control circuit 13 Second switch circuit 14 Second reference voltage generation circuit 15 Third switch circuit 16 Second current limiting circuit

Claims (4)

(57) [Claims] A rectifier circuit for rectifying a commercial AC power supply, and a first switch for turning on and off a rectified output by the rectifier circuit.
Charging a latch circuit, an output of said first switch circuit, to the charge
And a first reference voltage for a rectified output voltage of the rectifier circuit.
A rectified output with respect to its first reference voltage.
A first reference voltage for changing an operation state according to a voltage change;
A pressure generating circuit, based on an operation change of the first reference voltage generating circuit, before
Turning on and off the rectified output by the first switch circuit;
A first switch control circuit for controlling, and the rectified output proportional to a peak voltage of the commercial AC power supply
By holding the voltage for a certain period of time,
A voltage fluctuation of the commercial AC power supply with respect to a predetermined voltage.
An AC voltage detection circuit for detecting, and a voltage change of the commercial AC power supply by the AC voltage detection circuit.
A third switch that turns on and off based on the detection result
A pitch controller, obtained from on-off operation of the third switch control circuit
Of the commercial AC power supply detected by the AC voltage detection circuit.
Operation of the first reference voltage generation circuit according to a voltage change
A second switch circuit for controlling the change, and wherein the AC voltage detection circuit detects a voltage change of the commercial AC power supply.
While detecting a drop with respect to the predetermined voltage,
The switch circuit sets the first reference voltage to 0.
Thus, regardless of the change in the rectified output voltage, the first base
While the quasi-voltage generating circuit is in operation, the first switch
Switch control circuit to turn off the first switch circuit.
A power supply characterized by being configured to last . 2. A rectifier circuit for rectifying a commercial AC power supply, and a first switch for turning on and off a rectified output of the rectifier circuit.
Charging a latch circuit, an output of said first switch circuit, to the charge
And a first reference voltage for a rectified output voltage of the rectifier circuit.
A rectified output with respect to its first reference voltage.
A first reference voltage for changing an operation state according to a voltage change;
A pressure generating circuit; and a first base for a rectified output voltage of the rectifier circuit.
Generating a second reference voltage lower than the reference voltage;
Operating state in accordance with the change of the rectified output voltage with respect to the reference voltage.
A second reference voltage generating circuit for changing the state, the first reference voltage generating circuit and the second reference voltage
The first switch operation is performed based on a change in the operation of the generation circuit.
A first switch for controlling on / off of the rectified output by a path.
Switch control circuit, and the rectified output proportional to the peak voltage of the commercial AC power supply.
By holding the voltage for a certain period of time,
A voltage fluctuation of the commercial AC power supply with respect to a predetermined voltage.
An AC voltage detection circuit for detecting, and a voltage change of the commercial AC power supply by the AC voltage detection circuit.
A third switch that turns on and off based on the detection result
A pitch controller, obtained from on-off operation of the third switch control circuit
Of the commercial AC power supply detected by the AC voltage detection circuit.
Operation of the first reference voltage generation circuit according to a voltage change
A second switch circuit for controlling the change, and wherein the AC voltage detection circuit detects a voltage change of the commercial AC power supply.
While detecting a drop with respect to the predetermined voltage,
A switch circuit for connecting the first reference voltage to the second reference voltage;
By switching to the voltage, the second reference voltage generation
A first switch control circuit corresponding to an operation period of a road;
The period of the off state of the first switch circuit by
The AC voltage detection circuit detects a predetermined voltage of the commercial AC power supply.
Is configured to be longer than when detecting
And a power supply device. 3. A rectifier circuit for rectifying a commercial AC power supply, and a first switch for turning on and off a rectified output of the rectifier circuit.
Charging a latch circuit, an output of said first switch circuit, to the charge
And a first reference voltage for a rectified output voltage of the rectifier circuit.
A rectified output with respect to its first reference voltage.
A first reference voltage for changing an operation state according to a voltage change;
A pressure generating circuit, based on an operation change of the first reference voltage generating circuit, before
Turning on and off the rectified output by the first switch circuit;
A first switch control circuit for controlling, and the rectified output proportional to a peak voltage of the commercial AC power supply
By holding the voltage for a certain period of time,
A voltage fluctuation of the commercial AC power supply with respect to a predetermined voltage.
An AC voltage detection circuit for detecting, and a voltage change of the commercial AC power supply by the AC voltage detection circuit.
A third switch that turns on and off based on the detection result
A pitch controller, obtained from on-off operation of the third switch control circuit
Of the commercial AC power supply detected by the AC voltage detection circuit.
According to the voltage fluctuation, the first switch circuit
And a third switch circuit for controlling on / off of the rectified output.
The AC voltage detection circuit is provided with a voltage fluctuation of the commercial AC power supply.
While detecting a drop with respect to the predetermined voltage, the third
A switch circuit for holding the first switch;
By short-circuiting the circuit, the rectified output voltage changes
Regardless, the off state of the first switch circuit is maintained.
A power supply device characterized by being configured as described above . 4. A rectifier circuit for rectifying a commercial AC power supply, and a first switch for turning on and off a rectified output of the rectifier circuit.
Switch circuit and the first switch for the rectified output by the rectifier circuit.
Current limiting circuit for limiting the output current from the switch circuit
And the first switch for the rectified output by the rectifier circuit.
Output current from the first current limiting circuit.
And a second current limiting circuit for limiting the current more greatly than in the case where the output of the first switch circuit is charged.
And a first reference voltage for a rectified output voltage of the rectifier circuit.
A rectified output with respect to its first reference voltage.
First reference potential for changing the operating state in accordance with the change in the voltage
A pressure generating circuit, based on an operation change of the first reference voltage generating circuit, before
Turning on and off the rectified output by the first switch circuit;
A first switch control circuit for controlling, and the rectified output proportional to a peak voltage of the commercial AC power supply
By holding the voltage for a certain period of time,
A voltage fluctuation of the commercial AC power supply with respect to a predetermined voltage.
An AC voltage detection circuit for detecting, and a voltage change of the commercial AC power supply by the AC voltage detection circuit.
A third switch that turns on and off based on the detection result
A pitch controller, obtained from on-off operation of the third switch control circuit
Of the commercial AC power supply detected by the AC voltage detection circuit.
The first current limiting circuit and the second current limiting circuit respond to a voltage change.
And the current limiting circuit is switched to the first switch circuit.
A third switch circuit for controlling a limit amount of the output current;
Wherein the AC voltage detection circuit and the voltage variation of the commercial AC power source
While detecting a drop with respect to the predetermined voltage, the third
The switch circuit holds the ON operation, whereby the second
1 for the output current from the first switch circuit.
The limitation by the current limiting circuit is performed by the second current limiting circuit.
Limit by the second current limiting circuit
A power supply device configured to maintain a state .