JP2000299980A - Switching power unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control operation of a switching power unit, as well as to reduce its power consumption during no-operation. SOLUTION: A switching power unit comprises a diode D2, which is connected to the main windings N1, N2 of a transformer and conducts during turn off of Q1, a shunt-regulator IC1, a photocoupler PC1 for signal transmission, and an auxiliary winding N3 supplying operation voltage from the transformer T1 to a control circuit A. Then a quaternary winding N4 wound homopolar as the main winding N1, a rectifying and filtering circuit with a diode D1 and a capacitor C1 connected in series to the output terminals of the quaternary windings N4, and a thyristor coupling circuit connecting transistors Q2, Q3, resistors R3, R4 and a capacitor 3 to a switch S1 and a current-limiter resistor R7, and trigger signal is input from an external control terminal C to a secondary control winding N2, thereby conducting transistors Q2, Q3 and causing the output to operate intermittently.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching power supply device in which the output is intermittently operated by an external signal in an inactive state in order to reduce the power consumption. Is a switching power supply device intended to output a rated output voltage by turning on a switch circuit provided on the secondary side of the switching power supply device in one shot.

[0002]

2. Description of the Related Art A conventional switching power supply device is of a type in which a power supply operation is turned on / off from an output side (secondary side) as shown in FIG. 2, and FIG. A circuit (dotted line) for reducing the power consumption is not used, and current limiting resistors R8 and R9 are connected to another DC power supply V2.
And a circuit in which the photocoupler PC2 and the transistor Q4 are connected, and the transistor Q
The signal generated by turning on the switching element 4 is transmitted to the control circuit A by the photocoupler PC2, the switching element Q1 for power conversion is turned off, and the oscillation is stopped.

[0003]

Since the above configuration is adopted, when the on / off control of the conversion switching element is performed from the normal output side, the power supply for driving the signal transmitting photocoupler (light emitting side). As a separate DC power supply is required, subject to design constraints taking safety standards into account,
In addition, there is a problem that the cost increases. As shown in FIG. 1, the present invention intermittently operates an output by an external control signal to reduce power consumption during non-operation without using a DC power supply separate from a controlled output, The return to the state can be performed by a switch operation from the secondary side.

[0004]

SUMMARY OF THE INVENTION A switching power supply according to the present invention is intended to solve the above-mentioned problems without separately using a power supply for driving a signal transmitting photocoupler (light emitting side). That is, the main winding N1 of the transformer connected to the power conversion switching element Q1, the output secondary control winding N2 wound in a different polarity from the winding N1, and connected to the winding N2, A diode D2 which conducts when the switching element Q1 is turned off, and a shunt regulator I
C1, a switching power supply comprising a signal transmitting photocoupler PC1, a control circuit A for driving the switching element Q1 by the photocoupler PC1, and an auxiliary winding N3 for supplying an operating voltage to the circuit A from a transformer T1. , A quaternary winding N4 wound in the same polarity as the main winding N1
A rectifying / smoothing circuit in which a diode D1 and a capacitor C1 are connected in series between output terminals of the quaternary winding N4, a switch S1, a current limiting resistor R7, transistors Q2 and Q3, resistors R3 and R4, and Capacitor C3
And a thyristor-coupling circuit formed by connecting the external control terminal C to the secondary control winding N2 to make the transistors Q2 and Q3 conductive and to operate the output intermittently. A switching power supply device characterized by the following.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) A rectifier in which a diode D1 and a capacitor C1 are connected in series between a quaternary winding N4 wound in the same polarity as the main winding N1 and an output terminal of the quaternary winding N4. A smoothing circuit and a thyristor coupling circuit that connects the transistors Q2 and Q3, the resistors R3 and R4, and the capacitor C3 to the switch S1 and the current limiting resistor R7 are configured. (2) A trigger signal is input from the external control terminal C to the secondary control winding N2 to make the transistors Q2 and Q3 conductive and to operate the output intermittently.

[0006]

FIG. 1 shows an embodiment of the present invention. This figure 1
This will be described with reference to FIG. (1) In order to stabilize the output voltage Vo, a reference voltage shunt regulator is passed through a diode D2 and a capacitor C2 for rectifying and smoothing the terminal voltage of a secondary control winding N2 wound in a different polarity from the main winding N1. In a power supply circuit configured by a control circuit that controls a pulse width or a frequency of the power conversion switching element Q1 by using signals of the IC1 and the signal transmission photocoupler PC1 to stabilize an output voltage, A) a quaternary winding N4 wound in the same polarity as the main winding N1, a diode D1 for rectifying and smoothing the output from the quaternary winding N4, a capacitor C1, and a switch S1 connected in series to the output; A thyristor coupling circuit (transistors Q2, Q3, resistors R3, R4,
(Consisting of a capacitor C3). Here, N
The four windings are wound in the same polarity direction as the N1 winding. This is because a voltage proportional to the input voltage applied to the main winding is obtained irrespective of the pulse width variation of the main switching element Q1 with on / off control. This is because, even if the main switching element Q1 shifts to the intermittent operation mode, a voltage proportional to the input voltage is obtained at N4, and it is necessary to operate the thyristor-coupled transistor circuit. (3) When a trigger signal for operating the transistor Q2 is input to the external control terminal C, the transistors Q2 and Q
3 is in a conductive state because it is thyristor-coupled,
The conduction state is maintained by the current supplied from the quaternary winding N4. At this time, a current flows from the photocoupler PC1 via the diode D3 connected to the transistor Q3, and the signal is transmitted to the primary side and given to the control circuit A. For this reason, the output voltage Vo decreases, and at the same time, the voltage of the drive winding N3 wound in the same polarity as the secondary winding N2 decreases, and the voltage of the control circuit A becomes insufficient. Then, the power conversion switching element Q1 stops operating. However, the intermittent operation is performed by repeating a process of applying a voltage to the control circuit A by the starting resistor R1 connected to the input power supply V1 and restarting. Thus, the output voltage Vo repeats the intermittent operation at a sufficiently low voltage. At this time, the load device connected to the output voltage Vo does not operate, and as a result, on / off control can be performed, and the input power can be reduced. (4) When the switch S1 is operated in a one-shot mode, the thyristor-coupling holding current is not supplied, the transistors Q2 and Q3 are turned off, and the circuit returns to a steady state. With the circuit configuration shown in FIG. 1, the power source for driving the signal transmitting photocoupler (light emitting side) as shown in FIG. 2 is unnecessary. Further, since the output voltage is intermittently operated as shown in FIG.
Input power of 3W to 0.6W in W class power supply
(At 240 VAC).

[0007]

According to the present invention, when low-power control of a switching power supply is performed, another power supply for driving a photocoupler (light-emitting side) for transmitting a signal is not required, so that design restrictions taking safety standards into consideration. And costs are lower. In addition, by adopting the circuit configuration of the present invention, the input power can be reduced as compared with the conventional circuit.

[Brief description of the drawings]

FIG. 1 is a switching power supply device showing one embodiment of the present invention.

FIG. 2 is a switching power supply device showing one conventional example.

FIG. 3 is an output voltage waveform in an intermittent operation state.

[Explanation of symbols]

A control circuit S1 switch (mechanical switch, relay, semiconductor switch) Q1 switching element for power conversion (FET, SCR,
IGBT) Q2, Q3, Q4 Transistor D1, D2, D3, D5 Diode C1, C2, C3 Capacitor PC1, PC2 Photocoupler N1 Main winding N2 Secondary control winding N3 Auxiliary winding N4 Quaternary winding IC1 Shunt regulator ( Zener diode) T1 transformer R1 starting resistors R2 current limiting resistors R3, R4 resistors R5, R6 resistor R7, R8, R9 current limiting resistor C external control terminals V1 input supply V2 input supply V ₀ output voltage

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[Procedure amendment]

[Submission date] February 10, 2000 (2000.2.1
0)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction contents]

[0004]

SUMMARY OF THE INVENTION A switching power supply according to the present invention is intended to solve the above-mentioned problems without separately using a power supply for driving a signal transmitting photocoupler (light emitting side). That is, the main winding N1 of the transformer connected to the power conversion switching element Q1, the main
Winding N1 and the output secondary control winding N2 wound on different poles,
Is connected to the output for a secondary control winding N2, a second diode that conducts during the off of the switching element Q1 D2
When the shunt regulator IC1, the signal transmitting photocoupler PC1, and a control circuit A for driving the switching element Q1 by the photocoupler PC1, the control circuit A
In for from transformer T1, the switching power supply comprising a auxiliary winding N3 for supplying an operating voltage, and the main winding N1 is wound on the same pole 4 winding N4, the 4 winding N
4, a rectifying / smoothing circuit in which a first diode D1 and a first capacitor C1 are connected in series between the output terminals of the first diode D1, a switch S1, a current limiting resistor R7, and a first transistor.
Data Q2 and second transistors Q3, a first resistor R3 the
Second resistor R4, and a thyristor coupling circuit formed by connecting a second capacitor C3 constitute, the thyristor coupling
The collector of the first transistor Q2 and the second transistor
The base of the transistor Q3 is connected to the second transistor Q3.
3 is connected to one end of the quaternary winding N4, and the first transistor
The connection between the base of the transistor Q2 and the second transistor Q3
Is connected to the photocoupler P via a third diode D3.
C1 and connected to the collector of the first transistor Q2.
The output voltage is supplied to the external control terminal C connected via the dynamic resistor R1.
The trigger signal generated by applying the voltage (V ₀ ) is input to the secondary control winding N2, and the first transistor Q2 and the
2 transistors Q2 and Q3 are turned on, and the photo
The signal from the plastic PC1 is transmitted to the control circuit A on the primary side.
The operation is stopped, and the starting resistor R1 connected to the control circuit A is stopped.
The switching power supply device operates the output intermittently by a process of restarting the switching power supply.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) A first winding between a quaternary winding N4 wound in the same polarity as the main winding N1 and an output terminal of the quaternary winding N4 .
A rectifying smoothing circuit diode D1 and the first capacitor C1 are connected in series, the switch S1, the current limiting resistor R7, a first transistor Q2, the second transistors Q3, a first resistor R3, a second resistor R4 and a thyristor coupling circuit connecting the second capacitor C3. (2) A trigger signal is input from the external control terminal C to the secondary control winding N2, and the first transistor Q2 and the second transistor
The transistor Q3 is turned on, and the output is operated intermittently.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction contents]

[0006]

FIG. 1 shows an embodiment of the present invention. This figure 1
This will be described with reference to FIG. (1) output voltage to stabilize the Vo, through primary winding N1 and a second diode D2 for rectifying and smoothing the terminal voltage of the secondary control winding N2 wound on different poles, a third capacitor C2 And a control circuit for controlling the output voltage to be stabilized by changing the pulse width or frequency of the power conversion switching element Q1 with the signals of the reference voltage shunt regulator IC1 and the signal transmission photocoupler PC1. in the power supply circuit, (2) the main winding N1 and the quaternary winding N4 wound in the same polarity, the first die <br/> diode D1 for rectifying and smoothing the output from the quaternary winding N4, A thyristor coupling circuit ( first transistor Q2, second transistor Q2) connected to a first capacitor C1, a switch S1 connected in series to its output, and a power limiting resistor R7 .
Transistor Q3, first resistor R3, second resistor R
4, the second capacitor C3). In addition,
Here, the N4 winding is wound in the same polarity direction as the N1 winding. This is because the input voltage applied to the main winding is irrespective of the pulse width variation of the main switching element Q1 accompanied with on / off control. This is because, even if the main switching element Q1 shifts to the intermittent operation mode, a voltage proportional to the input voltage is obtained at N4, and it is necessary to operate a thyristor-coupled transistor circuit. (3) When a trigger signal for operating the transistor Q2 is input to the external control terminal C, the first transistor Q
Since the second transistor Q3 and the second transistor Q3 are thyristor-coupled, they become conductive, and the conductive state is maintained by the current supplied from the quaternary winding N4. At this time, the second
The third diode D3 connected to the transistor Q3
, A current flows from the photocoupler PC1, and the signal is transmitted to the primary side and supplied to the control circuit A. For this reason, the output voltage Vo decreases, and at the same time, the voltage of the drive winding N3 wound in the same polarity as the secondary winding N2 decreases, and the voltage of the control circuit A becomes insufficient. Then, the power conversion switching element Q1 stops operating. However, the intermittent operation is performed by repeating a process of applying a voltage to the control circuit A by the starting resistor R1 connected to the input power supply V1 and restarting. Thus, the output voltage Vo repeats the intermittent operation at a sufficiently low voltage. At this time, the load device connected to the output voltage Vo does not operate, and as a result, on / off control can be performed, and the input power can be reduced. (4) When the switch is operated, the switch S1 is operated in one shot, so that the thyristor-coupled holding current is not applied, and the first transistor Q2 and the second transistor
The transistor Q3 turns off and returns to a steady state. Figure 1 above
With this circuit configuration, a driving power supply for a signal transmitting photocoupler (light emitting side) as shown in FIG. 2 is unnecessary. Further, as shown in FIG. 3, since the output voltage is operated intermittently, when comparing the input power with the conventional circuit,
For example, in a power supply with a rated power of about 30 W, the input power can be reduced from 3 W to 0.6 W (at 240 V AC).

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of the drawings]

FIG. 1 is a switching power supply device showing one embodiment of the present invention.

FIG. 2 is a switching power supply device showing one conventional example.

FIG. 3 is an output voltage waveform in an intermittent operation state.

[Description of reference symbols] A control circuit S1 switch (mechanical switch, relay, semiconductor switch)
Switch) Q1 Power conversion switching element (FET, SCR,
IGBT)Q2 First transistor Q3 The second transistor Q4 Third transistor D1 First diode D2 Second diode D3 Third diode D5 Fourth diode C1 First capacitor C3 Second capacitor C2 Third capacitor  PC1, PC2 Photocoupler N1 Main winding N2 Secondary control winding N3 Auxiliary winding N4 Quaternary winding IC1 Shunt regulator (constant voltage diode) T1 Transformer R1 Starting resistance R2, 7-9 Current limiting resistor R3FirstresistanceR4 Second resistance  R5, R6 Resistance C External control terminal V1 Input power V2 Input power V₀ Output voltage ──────────────────────────────────────────────── ─────

[Procedure amendment]

[Submission Date] May 10, 2000 (2000.5.1)
0)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction contents]

[0004]

SUMMARY OF THE INVENTION A switching power supply according to the present invention is intended to solve the above-mentioned problems without separately using a power supply for driving a signal transmitting photocoupler (light emitting side). That is, a main winding N1 of a transformer connected to the power conversion switching element Q1, an output secondary control winding N2 wound in a different polarity from the main winding N1,
A second diode D2 connected to the output secondary control winding N2 and conducting when the switching element Q1 is turned off;
A shunt regulator IC1, a signal transmitting photocoupler PC1, a control circuit A for driving the switching element Q1 by the photocoupler PC1, and the control circuit A
In the switching power supply device comprising an auxiliary winding N3 for supplying an operating voltage from a transformer T1, a quaternary winding N4 wound in the same polarity as the main winding N1, and the quaternary winding N
4, a rectifying / smoothing circuit in which a first diode D1 and a first capacitor C1 are connected in series between the output terminals, a switch S1, a current limiting resistor R7, a first transistor Q2 and a second transistor Q3, A thyristor coupling circuit is formed by connecting the first resistor R3, the second resistor R4, and the second capacitor C3, and the collector of the first transistor Q2 and the second transistor Q3 of the thyristor coupling circuit are connected. Connecting the base, the second transistor Q
3 is connected to the end of the fourth winding N4 ,
External control in which the base of the first transistor Q2 and the collector of the second transistor Q3 are connected to the photocoupler PC1 via the third diode D3, and the collector of the first transistor Q2 is connected via the starting resistor R1 Terminal C
A trigger signal generated by applying an output voltage (V ₀ ) to the second control winding N2 is input to the first transistor Q2
And the second transistors Q2 and Q3 are turned on, the signal from the photocoupler PC1 is transmitted to the control circuit A on the primary side, the operation is stopped, and the operation is restarted by the starting resistor R1 connected to the control circuit A. A switching power supply device wherein an output is intermittently operated by a process. ────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] May 24, 2000 (2005.2.
4)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction contents]

[0004]

SUMMARY OF THE INVENTION A switching power supply according to the present invention is intended to solve the above-mentioned problems without separately using a power supply for driving a signal transmitting photocoupler (light emitting side). That is, a main winding N1 of a transformer connected to the power conversion switching element Q1, an output secondary control winding N2 wound in a different polarity from the main winding N1,
A second diode D2 connected to the output secondary control winding N2 and conducting when the switching element Q1 is turned off;
A shunt regulator IC1, a signal transmitting photocoupler PC1, a control circuit A for driving the switching element Q1 by the photocoupler PC1, and the control circuit A
In the switching power supply device comprising an auxiliary winding N3 for supplying an operating voltage from a transformer T1, a quaternary winding N4 wound in the same polarity as the main winding N1, and the quaternary winding N
4, a rectifying / smoothing circuit in which a first diode D1 and a first capacitor C1 are connected in series between the output terminals, a switch S1, a current limiting resistor R7, a first transistor Q2 and a second transistor Q3, A thyristor coupling circuit is formed by connecting the first resistor R3, the second resistor R4, and the second capacitor C3, and the collector of the first transistor Q2 and the second transistor Q3 of the thyristor coupling circuit are connected. Connecting the base, the second transistor Q
3 is connected to the end of the fourth winding N4 ,
External control in which the base of the first transistor Q2 and the collector of the second transistor Q3 are connected to the photocoupler PC1 via the third diode D3, and the collector of the first transistor Q2 is connected via the starting resistor R1 Terminal C
A trigger signal generated by applying an output voltage (V ₀ ) to the second control winding N2 is input to the first transistor Q2
And the second transistors Q2 and Q3 are turned on, the signal from the photocoupler PC1 is transmitted to the control circuit A on the primary side, the operation is stopped, and the operation is restarted by the starting resistor R1 connected to the control circuit A. A switching power supply device wherein an output is intermittently operated by a process.

Claims (1)

[Claims] 1. A main winding of a transformer connected to a switching element for power conversion, a secondary control winding for output wound in a different polarity from the winding, and the switching element connected to the winding. A switching circuit comprising: a diode that conducts when the power supply is off; a shunt regulator; a signal transmitting photocoupler; a control circuit that drives the switching element using the photocoupler; and an auxiliary winding that supplies an operating voltage from a transformer to the circuit. In a power supply device, a quaternary winding wound in the same polarity as a main winding, a rectifying and smoothing circuit in which a diode and a capacitor are connected in series between output terminals of the quaternary winding, a switch, and a current limiting resistor And a thyristor coupling circuit formed by connecting a transistor, a resistor, and a capacitor, and inputting a trigger signal from an external control terminal to the secondary control winding. Into conduction transistor, switching power supply unit for causing intermittently operates the output.