JPH077926A - Power supply apparatus - Google Patents

Abstract

PURPOSE:To convert the voltage of an AC power supply into a DC voltage by a simple constitution which does not use a transformer. CONSTITUTION:A circuit constitution is composed of a rectifying circuit 2 connected to an AC power supply 1, of a switching circuit 3 and a capacitor 4, of an output-voltage limiting circuit 5, of a switching control circuit 7 controlling the switching circuit 3 and of a phase-angle-proportional-voltage generation circuit 6. Then, the switching circuit 3 is turned on until the output terminal voltage of the rectifying circuit 2 reaches the sum voltage of an output voltage and of a phase-angle-proportional voltage which is generated by the phase-angle- proportional-voltage generation circuit 6. When the switching circuit 3 is turned on, electric power is supplied to the capacitor 4 and a load 8. When the switching circuit 3 is turned off, electric power is supplied to the load 8 from the capacitor 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device for an electronic circuit in which an electronic circuit of a device is used without being insulated from a commercial power supply.

[0002]

2. Description of the Related Art In recent years, home electric appliances equipped with an electronic circuit including an active element have become common. Most wireless-related electronic circuits form a secondary circuit that is insulated from a commercial power source, but many home electric appliances have an electronic circuit that is not insulated from a commercial power source. When an electronic circuit is mounted on a device, its configuration is generally composed of a power supply circuit and other electronic circuits.
For convenience of description below, the commercial power supply will be referred to as a primary circuit.

An example of the power supply for the above-mentioned conventional primary circuit will be described below with reference to FIG. Reference numeral 1 is an AC power supply, 4 is a capacitor, 8 is an electronic circuit that serves as a load of the power supply device, 18 is a transformer, and 19 is a rectifier.

The operation of the conventional power supply device configured as described above will be described. The AC voltage of AC power supply 1 is
The voltage is dropped by the transformer 18. The AC signal whose voltage has dropped is rectified by the rectifier 19, then smoothed by the capacitor 4, converted into a DC voltage, and supplied to the load 8. The DC voltage obtained at the output at this time is determined by the voltage of the terminal output of the transformer 18.

[0005]

However, in the above structure, since the transformer is used, the amount of material used is large, the cost is high, and the cost is hard to be lowered.
There are problems such as heavy, large, inefficient, and much heat generation.

The present invention is intended to solve the problems of the conventional method, and a first object of the present invention is to provide a power supply device using an electronic circuit that does not use a transformer. The second to eleventh objectives are to provide second to eleventh means for achieving the first objective.

[0007]

The first means for achieving the first object of the present invention is to provide a rectifier circuit connected to an AC power supply, a switch circuit, a capacitor, and an output voltage of a certain value or more. An output voltage limiting circuit for limiting the voltage so as not to rise, a phase angle proportional voltage generating circuit for generating a phase angle proportional voltage proportional to the phase angle of the output of the rectifying circuit, and a switch with the sum voltage of the output voltage and the phase angle proportional voltage. And a switch control circuit for controlling the power supply.

The second means of the present invention for achieving the second object is to limit the rectifier circuit connected to the AC power source, the switch circuit, the capacitor, and the output voltage so as not to rise above a certain value. An output voltage limiting circuit, a phase angle proportional voltage generating circuit for generating a phase angle proportional voltage proportional to the phase angle of the output of the rectifying circuit, a load current detecting circuit for detecting a current flowing through a load, an output voltage and a phase angle. A power supply device comprising a switch control circuit for controlling a switch with a sum voltage of a proportional voltage and a voltage corresponding to a load current generated by a load current detection circuit.

The third means of the present invention for attaining the third object is, in addition to the configuration of the second means of the present invention, detects when the output current increases to a constant value and detects the phase angle proportional voltage. The power supply device is provided with a phase angle limiting circuit that limits the proportional voltage of the generating circuit.

According to a fourth aspect of the present invention for achieving the fourth object, in addition to the configuration of the second means of the present invention, when the output current increases to a constant value, it is detected and a load current detection circuit is provided. The power supply device is provided with a corresponding voltage limiting circuit that limits the corresponding voltage.

The fifth means of the present invention for attaining the fifth object is, in addition to the configuration of the second means of the present invention, detects when the output current increases to a constant value and switches circuit 3
The power supply device is provided with a switch voltage limiting circuit that limits the switch voltage.

According to a sixth aspect of the present invention for achieving the sixth object, in addition to the configuration of the second means of the present invention, when the output voltage decreases to a constant value, it is detected and the phase angle proportional voltage is detected. The power supply device includes a second phase angle limiting circuit that limits the proportional voltage of the generating circuit.

According to a seventh means of the present invention for achieving the seventh object, in addition to the configuration of the second means of the present invention, when the output voltage decreases to a constant value, it is detected, and a load current detection circuit is provided. The power supply device is provided with a second corresponding voltage limiting circuit that limits the corresponding voltage.

In addition to the configuration of the second means of the present invention, the eighth means of the present invention for achieving the eighth object detects the output voltage decreasing to a constant value and detects the switch of the switch circuit. The power supply device includes a second switch voltage limiting circuit that limits the voltage.

A ninth means of the present invention for achieving the ninth object is to add the phase angle proportional voltage to the first aspect in addition to the configuration of any one of the first means to the eighth means of the present invention. The power supply device is provided with a first voltage generation circuit that does not exceed the voltage.

The tenth means of the present invention for achieving the tenth object limits the current passing through the switch circuit in addition to the configuration of any one of the first means to the ninth means of the present invention. The power supply device is provided with a current limiting circuit.

The eleventh means of the present invention for achieving the eleventh object is to prevent the rectifier circuit connected to the AC power source, the switch circuit, the capacitor, and the output voltage from rising above a certain value. An output voltage limiting circuit for limiting, a phase angle proportional voltage generating circuit for generating a phase angle proportional voltage proportional to the phase angle of the rectifier circuit output, and a switch control circuit for controlling the switch with a mixed voltage of the output voltage and the phase angle proportional voltage. And the power supply device.

[0018]

The first means of the present invention operates so as to convert an AC voltage into a DC voltage without using a transformer. That is, when the output voltage of the rectifier circuit reaches the sum voltage of the output voltage of the power supply and the voltage proportional to the phase angle of the AC voltage at the output of the rectifier circuit, the switch control circuit is turned on and off. Send a signal to. When the output terminal voltage of the rectifier circuit exceeds the peak and approaches 0 again to reach the above sum voltage, the switch control circuit turns the switch circuit from OFF to ON again. When the switch circuit is on, power is supplied to the load and the capacitor, and when the switch circuit is off, power is supplied from the capacitor to the load.

When the load current is small and the output voltage is limited by the output voltage limiting circuit, the switch voltage is the sum of the voltage determined by the output voltage limiting circuit and the phase angle proportional voltage, and the load current is large. When the voltage is not limited by the output voltage limiting circuit, the sum voltage of the output voltage and the phase angle proportional voltage at that time becomes the switch voltage.

In the second means of the present invention, the following operation is added to the above first means. The current flowing in the load is detected by the load current detection circuit, and the switch control circuit can be controlled by the voltage obtained by adding this voltage to the above sum voltage, so that electric power according to the load current can be supplied.

In the third means to the eighth means of the present invention, the following actions are added to the second means of the present invention.

That is, in the third means of the present invention,
The current flowing through the load is detected by the load current detection circuit, and when the load current increases to a certain value, this is detected and the phase angle proportional voltage is forcibly reduced.

Further, the fourth means of the present invention is such that when the output current detection circuit detects an increase in the output current to a constant value, it acts so as to decrease the added amount that has been added according to the output current. is there. Of course, the case where the added amount is 0 is included.

According to a fifth aspect of the present invention, when the load current detection circuit detects an increase in the current flowing through the load to a constant value,
It acts to reduce the switch voltage.

The sixth means of the present invention is such that when the output voltage detection circuit detects a decrease in the output voltage to a constant value, the phase angle proportional voltage is forcibly decreased.

The seventh means of the present invention is such that, when the output voltage detection circuit detects a drop in the output voltage to a constant value, it acts so as to reduce the added amount that has been added according to the output current. . Of course, the case where the added amount is 0 is included.

The eighth means of the present invention is to act so as to decrease the switch voltage when the output voltage detection circuit detects a decrease in the output voltage to a constant value.

The ninth means of the present invention is such that, in addition to the operation of the first means of the present invention, the first voltage generating circuit functions so as to limit the increase in the phase angle proportional voltage.

The tenth means of the present invention, in addition to the operation of the first means of the present invention, acts so as to limit the current supplied to the switch circuit, load and capacitor by the current limiting circuit.

The eleventh means of the present invention further divides the phase angle proportional voltage of the first means of the present invention into a constant ratio to obtain a change amount added to the output voltage with respect to the change of the AC voltage. Acts to reduce.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A power supply device according to an embodiment of the first means of the present invention will be described below with reference to FIG. Reference numeral 1 is an AC power supply, which has output terminals A and B. A rectifier circuit 2 has an anode connected to the output terminal A of the AC power supply 1.
In this embodiment, the rectifier circuit 2 is composed of one diode, and half-wave rectification is performed. Of course, there is no problem in the configuration of full-wave rectification. Reference numeral 3 is a switch circuit for supplying or stopping the supply of the AC power rectified by the rectifier circuit 2 to the output side, and a transistor is used in this embodiment. The emitter of this transistor is connected to the input side of the switch circuit 3, that is, the cathode of the rectifier circuit 2, and the collector is connected to the output side of the switch circuit 3. By controlling the base of this transistor,
Controls conduction between collectors. 4 is a switch circuit 3
Is a capacitor for accumulating the electric charge that has passed through, one end of which is connected to the collector which is the output side terminal of the switch circuit 3, and the other end of which is connected to the B side terminal of the AC power supply.

Reference numeral 5 is an output voltage limiting circuit that detects when the output voltage of the capacitor 4 rises to a certain value and acts on the switch circuit 3 to limit the output voltage from rising any further. The output voltage limiting circuit 5 is
The constant voltage diode 5a, the resistors 5b and 5e, and the transistors 5c and 5d are connected as follows. The cathode of the constant voltage diode 5a is connected to the output terminal E of the switch circuit 3, and the resistor 5b and the base of the transistor 5c are connected to the anode. The collector of the transistor 5c has a resistor 5e and a transistor 5e.
The base of d is connected, and the other end of the resistor 5e is connected to the output terminal C of the rectifier circuit. The other end of the resistor 5b and the emitters of the transistors 5c and 5d are connected to B of the AC power supply 1.
It is connected to the side terminal. The collector of the transistor 5d that is the output of the output voltage limiting circuit 5 is connected to the base of the transistor that is the control terminal of the switch circuit 3.

Reference numeral 6 is a phase angle proportional voltage generating circuit for generating a voltage proportional to the phase angle of the AC rectified voltage appearing in the rectifying circuit 2. The phase angle proportional voltage generation circuit 6 includes a resistor 6a
The same 6b and a capacitor are connected as follows. The resistors 6a and 6b are connected in series between the output terminal C of the rectifier circuit and the B-side terminal of the AC power source 1, and the resistor 6b is connected.
A capacitor 6c is connected in parallel with. The phase angle proportional voltage output from the phase angle proportional voltage generation circuit is output from the connection point of the resistors 6a and 6b, and the capacitor 4
Is connected to a sum voltage generation circuit 7a which generates a sum voltage of the output voltage of the above and the phase angle proportional voltage. That is, the output terminal E of the switch circuit 3 and the output of the phase angle proportional voltage generation circuit 6 are connected to the input terminal of the sum voltage generation circuit 7a, and the sum voltage of these two is output to the output of the sum voltage generation circuit 7a. Is generated.

Reference numeral 7 is a switch control circuit, and in this embodiment, a sum voltage generation circuit 7a, a comparator 7b,
It is composed of a transistor 7c, a resistor 5e forming the output voltage limiting circuit 5, and a transistor 5d. The output of the sum voltage generation circuit 7a and the output terminal C of the rectifier circuit are connected to the input of the comparator 7b, and the output of the comparator 7b is connected to the base of the transistor 7c. The collector of the transistor 7c is connected to the base of the transistor 5d, and the emitter is connected to the B side terminal of the AC power supply. Reference numeral 8 is a load composed of an electronic circuit, and is connected to both ends of the capacitor 4.

The operation of this embodiment will be described below. The polarity of the voltage of the AC power supply 1 is 0 in the direction in which the rectifier circuit 2 is conductive
Suppose that it went above V. At this time, the resistor 5e of the switch control circuit 7 acts as a bias resistor, and the transistor 5d is turned on. As a result, a current flows through the base of the transistor that constitutes the switch circuit 3. This causes a current to flow from the emitter to the collector, turning on the switch circuit 3 and supplying power to the capacitor 4 and the load 8. And the voltage of the output terminal E of the switch circuit 3 is
When the operating voltage of the constant voltage diode 5a forming the output voltage limiting circuit 5 is reached, the transistor 5c is turned on and a current flows through the resistor 5e. However, for simplicity of explanation, the on-voltage of the transistor of about 0.6 V is ignored. As a result, the transistor 5d tries to turn off because the base voltage becomes almost the same potential as the emitter. However, since the load 8 is consuming power at this time, the voltage across the terminals of the capacitor 4 has dropped. Therefore, the transistor 5c tries to turn on again. After all, the transistor 5c operates so that a current such that the voltage of the output terminal E of the switch circuit 3 becomes stable at the operating voltage of the constant voltage diode 5a flows in the switch circuit 3. In this case, the output voltage limiting circuit 5 does not operate when the load current is large and the terminal voltage of the capacitor 4, which is the output voltage, does not reach the operating voltage of the constant voltage diode 5a. When the voltage of the output terminal C of the rectifier circuit 2 continues to rise and exceeds the sum voltage of the voltage constantly generated by the phase angle proportional voltage generation circuit 6 and the voltage between the terminals of the capacitor 4, the output of the comparator 7b becomes high, The transistor 7c turns on. As a result, the transistor 5d turns off the switch circuit 3. When the switch circuit 3 is turned off, the load 8 is supplied with power from the capacitor 4.

When the voltage of the output terminal C of the rectifier circuit 2 further rises and reaches a peak, and then starts to drop and drops to the output voltage of the sum voltage generation circuit 7a, the comparator 7b
Goes low, turning off the transistor 7c.
When the transistor 7c turns off, the transistor 5d turns on the switch circuit 3 again using the resistor 5e as a bias resistor.

When the output terminal voltage of the rectifier circuit 2 further drops and becomes equal to or lower than the voltage of the output terminal E of the switch circuit 3, the transistor 5d is turned off.

When the AC power supply voltage becomes 0 V and starts to rise again, the above-described operation is repeated and the power supply device supplies power to the load 8. Since the phase angle proportional voltage generation circuit 6 generates a voltage proportional to the phase angle of the AC power supply, it increases when the AC power supply voltage rises and decreases when the AC power supply voltage falls. That is, the characteristic of the phase angle proportional voltage generation circuit 6 is that the switch circuit 3 operates after a constant time from 0 V of the AC voltage having a constant frequency.

Next, an embodiment of the second means of the present invention will be described with reference to FIG. The same elements as those in the embodiment of the first means are designated by the same reference numerals, and the following description will be omitted. Reference numeral 9 is a load current detection circuit that detects a load current flowing through the load 8. The load current detection circuit 9 includes a resistor 9
a. 9b. 9c and the transistor 9d are connected as follows. That is, capacitor 4 and load 8
A resistor 9a is connected between the resistor 9a, a resistor 9c on the output side of the resistor 9a, and a resistor 9b on the input side, and resistors 9d, 9c, 9e are respectively connected to the base, emitter and collector of the transistor 9d. Connected. The other end of the resistor 9e is connected to the B-side terminal of the AC power supply.

The output terminal of the load current detection circuit 9 is a resistor 9
At both ends of e, the resistor 9e generates a voltage proportional to the load current. The output of the resistor 9e is connected to the sum voltage generation circuit 7a.

The operation of this embodiment will be described below centering on the operation of the load current detection circuit 9. When a current flows through the load 8, a voltage corresponding to the current flowing through the load 8 is generated in the resistor 9a. When a current flows through the resistor 9a, the bias resistor 9b turns on the transistor 9d. At this time, the collector current of the transistor 9d is determined by the emitter resistor 9c. Therefore resistor 9e
A voltage corresponding to the load current is also generated at both ends of the. The voltage of the resistor 9e is the sum voltage generation circuit 7a of the switch control circuit 7.
The voltage at which the switch circuit 3 is turned off increases when the load current is large and decreases when the load current is small. That is, this means that when the load current is large, the power that can be supplied to the load can be increased, and when the load current is small, the power that can be supplied to the load can be reduced. That is, the present embodiment has a configuration in which the supplied power can be changed according to the load current.

Next, an embodiment of the third means of the present invention will be described with reference to FIG. The same elements as those in the above-mentioned respective embodiments are given the same numbers and their explanations are omitted. Reference numeral 10 is a phase angle limiting circuit that detects when the output current increases to a certain value and limits the phase angle. The phase angle limiting circuit 10 has the following circuit configuration. The emitter of the transistor 10b is connected to the input side of the resistor 9a,
A resistor 10a is connected to the base of b. The other end of the resistor 10a is connected to the output side of the resistor 9a. A resistor 1 is connected to the collector of the transistor 10b.
One end of 0c and the base of the transistor 10e are connected. The other end of the resistor 10c and the emitter of the transistor 10e are connected to the B-side terminal of the AC power supply. A resistor 10d is connected to the collector of the transistor 10e, and the other end of the resistor 10d is connected to the output terminal of the phase angle proportional voltage generating circuit 6. A resistor 10f is connected between the base and emitter of the transistor 10b.

The operation of this embodiment will be described below. The voltage between the terminals of the resistor 9a is divided by the resistors 10a and 10f and applied between the emitter and base of the transistor 10f. Therefore, when the load current increases and the voltage applied to the resistor 10f reaches the operating voltage of the transistor 10b, the transistor 10b turns on. Transistor 10
When b turns on, the transistor 10e also turns on, the collector-emitter voltage of the transistor 10d becomes almost 0, and the resistor 10d is equivalently connected in parallel with the resistor 6b. Therefore, the phase angle proportional voltage decreases. As a result, the switch voltage of the switch circuit 3 drops.
That is, when the load current increases to a certain value, the switch voltage decreases and the power supply to the load 8 decreases.

As a result, it is possible to prevent the destruction of circuit parts due to overload or load short-circuit, or to use parts with small ratings.

Next, an embodiment of the fourth means of the present invention will be described with reference to FIG. The resistor 7d that constitutes the switch control circuit 7 is connected to the output of the load current detection circuit 9, and the other end is connected to the sum voltage generation circuit 7a of the switch control circuit 7. Reference numeral 11 is a corresponding voltage limiting circuit that detects when the output current increases to a certain value and limits the voltage corresponding to the output of the load current detection circuit 9. The corresponding voltage limiting circuit 11 has the following circuit configuration. The emitter of the transistor 11b is connected to the input side of the resistor 9a that constitutes the load current detection circuit 9, and the resistor 11a is connected to the base. The other end of the resistor 11a is connected to the output side of the resistor 9a. Transistor 11
One end of the resistor 11c and the base of the transistor 11e are connected to the collector of b. The other end of the resistor 11c and the emitter of the transistor 11e are connected to the AC power source B
It is connected to the side terminal. A resistor 11d is connected to the collector of the transistor 11e, and the other end of the resistor 11d is connected to a connection point between the resistor 7d forming the switch control circuit 7 and the sum voltage generation circuit 7a. A resistor 11f is connected between the base and emitter of the transistor 11b.

The operation of this embodiment will be described below. Resistor 9
The voltage across the terminal a is divided by the resistors 11a and 11f and applied between the emitter and base of the transistor 11b. Therefore, when the load current increases and the voltage applied to the resistor 11f reaches the operating voltage of the transistor 11b, the transistor 11b turns on. Transistor 11
When b turns on, the transistor 11e also turns on, and the collector-emitter voltage of the transistor 11d becomes almost 0. When the collector-emitter voltage of the transistor 11d becomes 0, the added voltage from the load current detection circuit 9 becomes equivalent to , The divided voltage by the resistors 7d and 10d is added. Therefore, the corresponding voltage by the load current detection circuit 9 decreases. As a result, the switch voltage of the switch circuit 3 decreases.

That is, in this embodiment, when the load current increases to a certain value, the switch voltage is lowered and the power supply to the load is lowered. This makes it possible to prevent the destruction of circuit components when an abnormality occurs due to overload or load short-circuit, and to reduce the rating of the components used.

Next, an embodiment of the fifth means of the present invention will be described with reference to FIG. The resistor 7e forming the switch control circuit 7 has one end connected to the output of the sum voltage generation circuit 7a and the other end connected to the inverting input of the comparator 7b. A switch voltage limiting circuit 12 limits the switch voltage of the switch circuit 3 by detecting when the output current increases to a certain value and lowering the output voltage of the sum voltage generating circuit 7a. The switch voltage limiting circuit 12 is
It has the following circuit configuration. The emitter of the transistor 12b is connected to the input side of the resistor 9a that constitutes the load current detection circuit 9, and the resistor 12a is connected to this base. The output side of the resistor 9a is connected to the other end of the resistor 12a. The collector of the transistor 12b is connected to one end of the resistor 12c and the base of the transistor 12e. The other end of the resistor 12c and the emitter of the transistor 12e are connected to the B side terminal of the AC power supply. A resistor 12d is connected to the collector of the transistor 12e, and the connection point between the resistor 7d and the sum voltage generation circuit 7a is connected to the other end of the resistor 12d. The resistor 12f is connected between the base and emitter of the transistor 12b.

The operation of this embodiment will be described below. This embodiment operates in substantially the same manner as the embodiment of the third means of the present invention. That is, when the transistor 12e operates, its collector and emitter have almost the same potential,
The reference voltage of the comparator is divided by the resistors 7e and 12d. Therefore, the switch voltage of the switch circuit 3 is lowered.

Next, an embodiment of the sixth means of the present invention will be described with reference to FIG. 13 is a second phase angle limiting circuit, which detects when the load voltage decreases to a certain value,
It acts to limit the proportional voltage of the phase angle proportional voltage generating circuit. That is, the second phase angle limiting circuit 13 has the following circuit configuration. A resistor 13g is connected between the resistor 9a constituting the load current detection circuit 9 and the load 8, and a constant voltage diode 13a and a resistor 13b are connected in series between the positive and negative terminals of the load 8. The base of the transistor 13c is connected to the connection point between them. A resistor 13d is provided at the collector of the transistor 13c.
And the base of the transistor 13e are connected, and the other end of the resistor 13d is connected to the connection point of the resistor 9a and the resistor 13g. The emitters of the transistors 13c and 13f are connected to the negative terminal of the load 8. Further, one end of the resistor 13e is connected to the collector of the transistor 13f, and the other end of the resistor 13e is connected to the output of the phase angle proportional voltage generating circuit 6.

The operation of this embodiment will be described below. When the load voltage drops to the operating voltage of the constant voltage diode 13a, the transistor 13c turns off, which causes the transistor 13f to turn on the resistor 13d as a bias resistor. When the transistor 13f is turned on, the resistor 6b and the resistor 13e forming the phase angle proportional voltage generating circuit 6 are equivalently connected in parallel. That is, the phase angle proportional voltage is forcibly reduced. As a result, the off-voltage of the switch circuit 3 is reduced, and the power supply to the load 8 is reduced. That is, when the load 8 becomes overloaded, this is detected and the supplied power is limited to protect the circuit. Even when the load 8 is completely short-circuited, a voltage is generated between both terminals of the resistor 13g, and the transistor 13f keeps the ON state. In the case of an incomplete short circuit, the transistor 13f is turned on even without the resistor 13g.

Next, an embodiment of the seventh means of the present invention will be described with reference to FIG. 14 is a second corresponding voltage limiting circuit, which detects when the load voltage decreases to a certain value,
It acts to limit the corresponding voltage of the load current detection circuit 9. Resistor 14 that constitutes the second corresponding voltage limiting circuit 14
b, same 14d, same 14g and transistor 14c, same 1
4f and the constant voltage diode 14a have the same connection relationship as the embodiment of the sixth means of the present invention. One end of the resistor 14e is connected to the collector of the transistor 14f, and the other end is connected to the input of the sum voltage generation circuit 7a from the output of the current detection circuit 9 via the resistor 7e.

In this embodiment, when the terminal voltage of the load 8 decreases to a constant value, the addition of the switch voltage from the load current detection circuit 9 is divided by the resistors 7e and 14e. To reduce the power supply to the load 8.

Next, an embodiment of the eighth means of the present invention will be described with reference to FIG. Reference numeral 15 is a second switch voltage limiting circuit that detects when the load voltage decreases to a certain value and limits the switch voltage. The resistors 15b, 15d, 15g, the transistors 15c, 15f, and the constant voltage diode 15a are The connection configuration is the same as that of the sixth embodiment of the invention. One end of the resistor 15e is connected to the collector of the transistor 15f, and the other end is connected to the sum voltage generation circuit 7
It is connected to the output terminal of a resistor 7e connected to the output of a.

With the above configuration, when the terminal voltage of the load 8 decreases to a certain value, it is detected and the output voltage of the sum voltage generating circuit 7a is reduced to the divided voltage of the resistors 7e and 15e. is there. In this way, the switch voltage of the switch circuit 3 is lowered to reduce the power supply to the load 8.

Next, an embodiment of the ninth means of the present invention will be described with reference to FIG. The present embodiment has a configuration in which a first voltage generating circuit 16 is added to the embodiment of the first means of the present invention. The first voltage generation circuit 16 is
It acts so that the phase angle proportional voltage does not exceed the first voltage, and is composed of a resistor 6a and a constant voltage diode 16a. The connection is such that the constant voltage diode 16a is in parallel with the resistor 6b which constitutes the phase angle proportional voltage generation circuit 6.

The operation of this embodiment will be described below. The AC power supply voltage rises to a certain value, and the resistors 6a and 6
When the voltage divided by b reaches the operating voltage of the constant voltage diode 16a, the constant voltage diode 16a operates even if the AC power supply voltage further rises, and operates to hold the operating voltage. . That is, the first voltage generation circuit 16 operates so as to maintain the phase angle proportional voltage output from the phase angle proportional voltage generation circuit 6 at a certain value or less. Therefore, the power consumption of the circuit including the switch circuit 3 can be limited.

Next, an embodiment of the tenth means of the present invention will be described with reference to FIG. Reference numeral 17 is a current limiting circuit that limits the current passing through the switch circuit 3, and is a resistor 17
a and a diode 17b configured by connecting two diodes in series. The connection is as follows. One end of the resistor 17a is connected to the emitter of the transistor forming the switch circuit 3, and the other end of the resistor 17a is connected to the output terminal of the rectifier circuit 2. Also diode 1
7b is connected to the terminal of the resistor that is opposite to the base of the transistor forming the switch circuit 3 and the emitter connection point of the resistor 17a.

The operation of this embodiment will be described below. When the switch circuit 3 is on, the base of this transistor
A voltage of about 0.6V is generated between the emitters. Further, a voltage of about (0.6V × 2 =) 1.2V is generated in the diode 17b. Therefore, a voltage corresponding to the difference between the two types of voltage is generated in the resistor 17a. Therefore, the current flowing through the circuit can be limited by appropriately setting the resistance value of the resistor 17a. As a result, it is possible to limit the current flowing through the switch circuit 3 or the capacitor 4, and it is possible to use a component with a small rating.

Next, an embodiment of the eleventh means of the present invention will be described with reference to FIG. Reference numeral 7 is a switch control circuit for controlling the switch with a mixed voltage of the output voltage and the phase angle proportional voltage. 7f and 7g are resistors, and a sum voltage generation circuit 7a
Together with this, it forms a mixing circuit of the output voltage and the phase angle proportional voltage. That is, the resistors 7f and 7g are connected in series between the output of the phase angle proportional voltage generating circuit 6 and the B-side terminal of the AC power source, and the sum voltage generating circuit 7a is input from the connection point of these two resistors. It is what is said.

The operation of this embodiment will be described below. In the embodiment of the first means of the present invention, the switch voltage is a voltage generated by applying a voltage proportional to the peak voltage of the AC voltage as the output voltage and the phase angle proportional voltage. On the other hand, in the present embodiment, the change amount of the AC proportional voltage added to the output voltage according to the change of the AC voltage is small. That is, when the AC voltage fluctuates, in the embodiment of the first means of the present invention,
When the AC voltage rises, the power supplied to the load increases, and when the AC voltage decreases, the power supplied to the load 8 decreases. On the other hand, in the present embodiment, the amount of change in the AC proportional voltage is adjusted by the resistor, so that the amount of power supplied to the load 8 can be made substantially constant even if the AC voltage changes. Is.

The idea of this embodiment can be easily applied to the embodiments of the second means of the present invention to the embodiments of the tenth means of the present invention.

[0063]

The first means of the present invention comprises a rectifier circuit connected to an AC power supply, a switch circuit, a capacitor, an output voltage limiting circuit for limiting the output voltage so as not to rise above a certain value, and A phase angle proportional voltage generating circuit for generating a phase angle proportional voltage proportional to the phase angle of the output of the rectifier circuit,
As a device consisting of a switch control circuit that controls the switch with the sum voltage of the output voltage and the phase angle proportional voltage, the power supply can be configured with an electronic circuit that does not use a transformer. It is possible to provide a power supply device that can reduce the load supply power when the supply amount does not decrease and when a load short circuit occurs and an overload occurs.

The second means of the present invention is to provide a rectifier circuit connected to an AC power source, a switch circuit, a capacitor,
An output voltage limiting circuit for limiting the output voltage so as not to rise above a certain value, a phase angle proportional voltage generating circuit for generating a phase angle proportional voltage proportional to the phase angle of the output of the rectifying circuit, and a current flowing through a load. A load current detection circuit for detecting,
In addition to the effect of the first means of the present invention, a device including a switch control circuit that controls a switch by a sum voltage of an output voltage, a phase angle proportional voltage, and a voltage corresponding to a load current generated by a load current detection circuit. The supplied power can be changed according to the change in the load current. That is, the power supply device can increase the supply power when the load current increases and decrease the supply power when the load current decreases.

According to the third means to the fifth means of the present invention, by detecting the load current, it is possible to strongly limit the load power supply at the time of overload and to provide a power supply device with a circuit protection function. Is.

According to the sixth means to the eighth means of the present invention, the load supply power at the time of overload can be strongly restricted by detecting the load voltage, and a power supply device with a circuit protection function can be provided. Is.

According to the ninth means of the present invention, the power consumption of the circuit is limited even if the AC voltage rises above a certain value. Therefore, the maximum rating of the circuit components used can be reduced. Can be.

According to the tenth means of the present invention, a power supply device in which the current ratings of the switch circuit and the capacitor are reduced can be provided as a structure having a current limiting circuit for limiting the current passing through the switch circuit. is there.

The eleventh means of the present invention is a rectifier circuit connected to an AC power source, a switch circuit, a capacitor, an output voltage limiting circuit for limiting the output voltage so as not to rise above a certain value, and a rectifier. A phase angle proportional voltage generation circuit that generates a phase angle proportional voltage proportional to the phase angle of the circuit output,
Provided as a device including a switch control circuit for controlling a switch with a mixed voltage of an output voltage and a phase angle proportional voltage, a power supply device capable of making a power supply amount to a load substantially constant even if an AC voltage fluctuates. It is possible.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a power supply device showing an embodiment of a first means of the present invention.

FIG. 2 is a circuit diagram showing an embodiment of the second means.

FIG. 3 is a circuit diagram showing an embodiment of the third means.

FIG. 4 is a circuit diagram showing an embodiment of the fourth means.

FIG. 5 is a circuit diagram showing an embodiment of the fifth means.

FIG. 6 is a circuit diagram showing an embodiment of the sixth means.

FIG. 7 is a circuit diagram showing an embodiment of the seventh means.

FIG. 8 is a circuit diagram showing an embodiment of the eighth means.

FIG. 9 is a circuit diagram showing an embodiment of the ninth means.

FIG. 10 is a circuit diagram showing an embodiment of the tenth means.

FIG. 11 is a circuit diagram showing an embodiment of the eleventh means.

FIG. 12 is a circuit diagram showing a conventional power supply device.

[Explanation of symbols]

 1 AC power supply 2 Rectifier circuit 3 Switch circuit 4 Capacitor 5 Output voltage limiting circuit 6 Phase angle proportional voltage generating circuit 7 Switch control circuit 9 Load current detection circuit 10 Phase angle limiting circuit 11 Corresponding voltage limiting circuit 12 Switch voltage limiting circuit 13 Second Phase angle limiting circuit 14 Second corresponding voltage limiting circuit 15 Second switch voltage limiting circuit 16 First voltage generating circuit 17 Current limiting circuit

Claims (11)

[Claims] 1. A rectifier circuit connected to an AC power supply, a switch circuit, a capacitor, an output voltage limiter circuit for limiting the output voltage so as not to rise above a certain value, and a phase angle of the output of the rectifier circuit. A power supply device comprising a phase angle proportional voltage generation circuit for generating a phase angle proportional voltage and a switch control circuit for controlling a switch with a sum voltage of an output voltage and a phase angle proportional voltage. 2. A rectifier circuit connected to an AC power supply, a switch circuit, a capacitor, an output voltage limiting circuit for limiting the output voltage so as not to rise above a certain value, and a phase angle of the output of the rectifying circuit. Phase angle proportional voltage generation circuit that generates a phase angle proportional voltage, load current detection circuit that detects the current flowing in the load, output voltage, phase angle proportional voltage, and voltage that corresponds to the load current generated by the load current detection circuit And a switch control circuit that controls the switch by the sum voltage of 3. The power supply device according to claim 2, further comprising a phase angle limiting circuit that detects when the output current increases to a constant value and limits the proportional voltage of the phase angle proportional voltage generating circuit. 4. The power supply device according to claim 2, further comprising a corresponding voltage limiting circuit that detects when the output current increases to a certain value and limits the corresponding voltage of the load current detection circuit. 5. The power supply device according to claim 2, further comprising a switch voltage limiting circuit that detects when the output current increases to a constant value and limits the switch voltage. 6. The power supply device according to claim 2, further comprising a second phase angle limiting circuit that detects when the load voltage decreases to a constant value and limits the proportional voltage of the phase angle proportional voltage generating circuit. 7. The power supply device according to claim 2, further comprising a second corresponding voltage limiting circuit that detects when the load voltage decreases to a constant value and limits the corresponding voltage of the load current detection circuit. 8. The power supply device according to claim 2, further comprising a second switch voltage limiting circuit that detects when the load voltage decreases to a certain value and limits the switch voltage. 9. The power supply device according to claim 1, further comprising a first voltage generating circuit that prevents the phase angle proportional voltage from exceeding the first voltage. 10. The power supply device according to claim 1, further comprising a current limiting circuit that limits a current passing through the switch circuit. 11. A rectifier circuit connected to an AC power supply, a switch circuit, a capacitor, an output voltage limiting circuit for limiting the output voltage so as not to rise above a certain value, and a phase proportional to the phase angle of the rectifier circuit output. A power supply device comprising a phase-angle-proportional voltage generating circuit for generating a proportional-angle voltage and a switch control circuit for controlling a switch with a mixed voltage of an output voltage and a phase-angle proportional voltage.