KR100286308B1 - Switching power apparatus for multi-circuit - Google Patents

Abstract

PURPOSE: A multi-circuit switching power apparatus is provided to achieve an improved component use efficiency and reduce cost by using the auxiliary power output from the first DC/DC converter as an auxiliary power for the second DC/DC converter. CONSTITUTION: A multi-circuit switching power apparatus comprises a first DC/DC converter(100A) and a second DC/DC converter(200A). The first DC/DC converter includes a transformer(T101) having a main coil(P) and an auxiliary coil(D); a transistor(FET101) for controlling current of the main coil; a regulator integration element(101) for controlling on/off operation of the transistor, based on the error information and current flowing through the transistor; a start resistance(R101) for supplying an input voltage(Vin) to a condenser(C102); a diode(D101) for rectifying the voltage output from the auxiliary coil and supplying the rectified voltage to the condenser(C102); the condenser(C102) for supplying the voltage supplied through the diode, to the regulator integration element as an auxiliary power; and a diode(D102) for rectifying and smoothing the voltage excited at a coil of the transformer, and outputting a voltage(Vout1). The second DC/DC converter outputs voltage by sharing the input voltage with the first DC/DC converter, and has a transformer which has no coils for supplying auxiliary power. The second DC/DC converter is configured to share the voltage output from the coil of the transformer of the first DC/DC converter.

Description

Multi-Circuit Switching Power Supplies {SWITCHING POWER APPARATUS FOR MULTI-CIRCUIT}

The present invention relates to a technology for supplying auxiliary power for operating the control unit inside each converter in a multi-circuit switching power supply circuit having an independent power converter, and in particular, the auxiliary power generated in one converter converts the auxiliary power of several other converters. A multi-circuit switching power supply is provided.

As an example of a multi-circuit switching power supply, a two-output DC-DC power converter is shown in FIG. FIG. 1 shows an example in which a switching regulator that performs a pulse ratio control (PRC) operation is generally operated in two circuits by using a regulator integrated device, which is an isolation type using a transformer.

That is, FIG. 1 is a block diagram illustrating an exemplary embodiment of a switching power supply according to the prior art. As shown in FIG. 1, the present invention converts a DC input voltage V _in of a predetermined level into a voltage of a desired level and transfers it to an output terminal. A transformer (T101) having lines (P) and (S) and having an auxiliary power winding (D) for supplying a driving voltage to an internal control circuit; A transistor FET101 for interrupting a current supplied to the main winding P; A regulator integrated device (101) controlling on / off of the transistor (FET101) by referring to error information returned from an output terminal and a current flowing through the transistor (FET101); A starting resistor (R101), a diode (D101), and a capacitor (C102) for supplying a driving voltage to the regulator integrated device (101); A diode (D102) and a capacitor (C103) for rectifying and smoothing the voltage excited by the winding (S) of the transformer (T101) to supply the output voltage (V _out1 ); The output voltage (V _out1) in order to stabilize the output voltage error comparator (102) to the (V _out1) compared to the reference voltage of the internal detecting the error value corresponding thereto and; A first DC / DC converter 100 is configured as a photocoupler 103 for returning error information detected by the error comparator 102 to the regulator integrated device 101, and the first DC / DC converter ( A second DC / DC converter 200 having the same configuration as that of 100 is connected in parallel to the input voltage V _in terminal and outputs an output voltage V _out2 therefrom. A description with reference to FIG. 5 is as follows.

First, the operation of the first DC / DC converter 100 will be described. The input voltage V _in of the first DC / DC converter 100 is supplied with a DC power source of about 140 to 260 V that is rectified and smoothed from a commercial power source.

One input terminal (+) of the input voltage (V _in ) passes through the primary winding (P) of the transformer (T101), and the other input terminal (−) through the transistor (FET101) and the current detection resistor (R103). ) Is connected. Accordingly, an intermittent current flows through the P winding of the transformer T101 by turning the transistor FET101 on and off, and the transistor FET101 is turned on by a driving voltage output from the regulator integrated device 101. Is off.

In order to supply the auxiliary power required by the regulator integrated device 101, the one input terminal (+) is connected to the input port P1 of the regulator integrated device 101 through a starting resistor R101, One side of the D winding of the transformer T101 is connected to the input port P1 through the rectifying diode D101, and a capacitor (C) is connected between the connection point and the other input terminal (−) of the input voltage V _in . C102) was connected.

In addition, in order for the regulator integrated device 101 to detect the current of the transistor FET101, the connection point of the source of the transistor FET101 and the resistor R103 is connected to the input port of the regulator integrated device 101. It connected to (P3). In order to stabilize the output voltage V _out1 , error information of the output circuit is fed back to the input port P5 of the regulator integrated device 101 through the photocoupler 103.

The D winding is wound around the transformer T101 for auxiliary power, and the S winding is wound for output, and they are insulated to prevent electric shock.

Since the S winding has one side connected to the ground terminal and the other side connected to the rectifying capacitor C103 through the rectifying diode D102, the voltage excited magnetically to the S winding by the current interruption of the P winding is rectified through them. , It is smoothed to obtain the desired output voltage V _out1 .

In order to stabilize the output voltage V _out1 , an error comparator 102 having an error comparison function with an internal reference voltage is connected to an output terminal, so that error information about the excess / under of the output voltage V _out1 is Through the above path, it is fed back to the regulator integrated device 101.

Since the operation of the second DC / DC converter 200 is the same as that of the first DC / DC converter 100, the description of the operation thereof will be omitted.

3 is a block diagram illustrating a part of an input side of the first DC / DC converter 100 or the second DC / DC converter 200 in FIG. 1 and expressing the regulator integrated device 101 in more detail. The basic functions of the regulator integrated device 101 will be described in more detail as follows.

Since one side of the auxiliary winding D winding is connected to the start control unit 101A inside the regulator integrated device 101 through the rectifier diode D101 and then again through the auxiliary power line L301, the regulator integrated device 101 is connected. Power is not supplied to the internal parts until they are started in the standby state.

However, when the regulator integrated element 101 is started and power is supplied to each part through the start control part 101A and the ballast 101B, each part is switched to an operation state.

When the respective parts inside the regulator integrated device 101 are switched to the operating state, the driving voltage of the transistor FET101 depends on the oscillator 101C responsible for turning on and off the transistor FET101 and the oscillation output of the oscillator 101C. The transistor FET101 is driven by a driver that generates.

In addition, various functions for driving the transistor FET101 are provided, and peripheral functions for detecting a current of the transistor FET101 are described as follows.

When the transistor FET101 is turned on, its source current flows to the ground terminal side through the resistor R103, so that the voltage detected through the resistor R103 increases as the amount of current increases. The comparator CP301 compares the voltage detected through the resistor R103 with a reference voltage V _ref and outputs a control signal for turning off the transistor FET101 when it exceeds the reference voltage V _ref . Since this control signal is orally calculated from the output signal of the oscillator 101C at the OR gate OR301 and the signal of the operation result is supplied to the driving unit 101D, the driving unit 101D is connected to the transistor FET101. The driving voltage supplied to the gate is cut off. As a result, overcurrent is prevented from flowing through the transistor FET101 by the control operation.

The oscillator 101C has a transistor FET101 according to two time constant elements, that is, a time constant set by the resistor R301 and a capacitor C301, and a time constant set by the resistor R302 and the capacitor C302. The length of the on and off time is determined.

However, since error information fed back through the photocoupler 103 is also supplied to the paths of the resistor R301 and the capacitor C301, the transistor FET101 is based on the superimposed signal supplied through the path. The on time is determined, and the off time is fixed.

4A and 4B, the starting operation of the regulator integrated device 101 is described as follows.

As in the general case, the operating voltage of the regulator integrated device 101 is a DC voltage of 10 to 30V and a DC current of several tens of mA, whereas the input voltage V _in is supplied with a high voltage (140 to 260V) of rectified commercial power. . In order to supply the auxiliary power of the regulator integrated device 101, the efficiency is lowered when the power is supplied only through the starting resistor R101. Furthermore, the resistor R101 itself must use a large power resistor. It is defective.

Therefore, the capacitor C102 is provided, and a minute current is supplied to the capacitor C101 through the start resistor R101 until the charge voltage of the capacitor C102 reaches the level of the preset start voltage. In this manner, the regulator integrated device 101 is designed to consume a small current of about 100 mu ALPHA while the capacitor C101 is being charged.

The operation against this is shown in Figs. 4A and 4B. That is, the point abc in FIG. 4A represents a change in the input current I _IN of the regulator integrated device 101, and the point a'-b'-c 'in FIG. 4B represents a change in the auxiliary power supply voltage. Between b'-c ', the regulator integrated element 101 consumes about 30 mA of current in the operating state, but at this time, the current is supplied to the capacitor C102.

When the regulator integrated device 101 starts to operate, a voltage is excited to the D winding of the transformer T101, and the excited voltage starts to be supplied to the auxiliary power supply through the rectifying diode D101. As shown after the point, a constant voltage can be secured.

What should not be overlooked here is that the regulator integrated device 101 once started maintains the hysteresis characteristics as shown in FIG. 4A so that the regulator is not stopped due to the voltage drop between c'-d '. It is provided with the capacitor | condenser C102 of the capacity which can ensure the discharge slope of liver.

In this way, an efficient auxiliary power source can be secured.

Meanwhile, referring to the waveform diagram of FIG. 5, an output process of the auxiliary power supply V _D supplied to the regulator integrated device 101 will be described.

The elements that determine the two time constants T1 and T2 of the oscillator 101C are resistors and capacitors R301 and C301 and R302 and C302, as described above, with the time constant T1. The capacitor C302 is repeatedly charged and discharged, and its voltage level is changed to the upper and lower reference voltage levels V _H and V _L set inside the regulator integrated device 101 as shown in FIG. 5A. The capacitor C301 is repeatedly charged and discharged by the time constant T2, and its voltage level is changed from the reference voltage V _HT to the ground potential as shown in FIG. The oscillator 101C logically combines the waveforms (a) and (b) of FIG. 5 to output a waveform as shown in (c) of FIG. 5, whereby the length of an on / off section of the transistor TET101 is obtained. Is determined.

The driving unit 101D outputs a driving signal corresponding to the waveform as shown in FIG. 5C to the gate side of the transistor FET101, thereby turning the transistor FET101 on and off to the transformer T101. Energy is transferred magnetically to generate the D winding terminal voltage V _D ′ as shown in FIG. 5E, and the output S winding terminal voltage V _S ′ is generated as shown in FIG. 5F. FIG. 5E shows the voltage appearing between the drain and the source of the transistor FET101.

At this time, the current I _S as shown in FIG. 5G is supplied to the rectifying diode D102, and the terminal voltage V _D 'of the D winding is supplied to the auxiliary power line L301 through the rectifying diode D101. The voltage V _D = V _D '-V _F appearing on the auxiliary power supply line L301 is obtained. Here, V _F means a voltage drop caused by the rectifying diode D101.

In general, in the switching regulator to the PRC operation V _D 'in the positive (+) peak-value (V_ {D ^ +}' ) and a negative polarity is - - ( 'V_ {D ^ }) is either () peak-value On the input voltage, the other side changes in proportion to the output voltage.

It is possible to change the polarity of the voltage V _D 'in such a way as to reverse the wiring of the D winding. In the example of description, three types of windings of the transformer T101 are formed so that V_ {D ^ +} is proportional to the output voltage. The operation waveform shown in Fig. 5E is selected so that V _D does not change even when the input voltage is changed (140 to 260 V DC).

In this manner, the winding of the winding D is determined in consideration of the polarity, and the number of windings of the winding _D is determined so as to correspond to the power supply voltage specification of the regulator integrated device 101.

However, in FIG. 1, for example, when adjusting the trimmer volume in the error comparator 202 to adjust the output voltage V _out2 of the second DC / DC converter 200, FIG. As shown by the dotted line in (f), the crest value of V _S 'is changed, and in conjunction with this, the crest value of V_ {D ^ +}' is also changed as shown in (e) of FIG. 5 to obtain a stabilized V _D '. It becomes impossible.

In view of this, in the related art, a local series regulator 204 is installed in place of the rectifying diode of the D winding as shown in FIG. 2, and the number of the D windings is appropriately increased so that V_ {D ^ +} 'is minimized. In this case, a method is adopted in which the output voltage of the series regulator 204 becomes the auxiliary power supply voltage required by the regulator integrated device 201.

However, in such a manner, an excessive V_ {D ^ +} 'crest value is typically generated in the D winding and consumed by the series regulator 204.

As described above, in the conventional multi-circuit switching power supply, when adjusting the volume of the trimmer in the error comparator to adjust the output voltage of the second DC / DC converter, the crest value of V _S 'is changed, and V_ {D ^ + } 'Crest value also changes, so that stabilized V _D ′ cannot be obtained.

In view of this, a local series regulator is installed instead of the rectifier diode of the D winding, and the output voltage of the series regulator is regulated even when the number of D windings is appropriately increased to minimize V_ {D ^ +} '. It adopts a method to make the auxiliary power supply voltage required for integrated devices.

However, in such a method, an excessive V_ {D ^ +} 'crest value is typically generated in the D winding, which is consumed by the series regulator, thereby reducing efficiency and increasing component cost.

Therefore, the technical problem to be achieved by the present invention is to ensure a stable auxiliary power supply without adding a local regulator, etc. for the auxiliary power supply, it is unnecessary to restrict the characteristics of the D winding for the auxiliary power supply, multi-power output It is to provide a multi-circuit switching power supply that generates a multi-power output in a stable state even if it needs to occur continuously.

1 is a block diagram of a multi-circuit switching power supply according to the prior art.

2 is another exemplary block diagram of a multi-circuit switching power supply according to the prior art.

3 is a block diagram illustrating in detail the regulator integrated device of FIG. 1; FIG.

4A is a hysteresis graph related to the starting operation in FIG.

4B is a waveform diagram of a startup operation in FIG. 1;

5A-5G are operational waveform diagrams of respective parts in FIG. 1;

Figure 6 is an exemplary block diagram of a multi-circuit switching power supply according to the present invention.

7A is an explanatory diagram of a startup operation 1 according to the present invention;

7B is an explanatory diagram of a startup operation 2 according to the present invention;

8A is an exemplary circuit diagram of a startup operation 3 according to the present invention.

8B is a waveform diagram of starting operation 3 according to the present invention;

9A is an exemplary circuit diagram of a startup operation 4 according to the present invention.

9B is a waveform diagram of a startup operation 4 according to the present invention.

10A is an exemplary circuit diagram of a startup operation 5 according to the present invention.

Fig. 10B is a waveform diagram of start operation 5 according to the present invention.

*** Description of the symbols for the main parts of the drawings ***

100A: first DC / DC converter 101,201: regulator integrated device

102,202: error comparator 103,203: photocoupler

200A: 2nd DC / DC converter

Figure 6 is a above, is converted to the level of voltage which purpose a direct-current input voltage (V _in) at a predetermined level the output stage shown in this illustrated as a diagram of one embodiment illustrative block diagram of the circuit switching power device for achieving the object of the present invention A transformer (T101) having a main winding (P) and (S) for transmission, and a winding (D) for auxiliary power for supplying a driving voltage to an internal control circuit; A transistor FET101 for interrupting a current supplied to the main winding P; A regulator integrated device (101) for controlling on and off of the transistor (FET101) based on error information returned from an output terminal and a current flowing through the transistor (FET101); A starting resistor R101 for supplying an input voltage V _in to the capacitor C102; A diode (D101) for rectifying the voltage output from the winding (D) and supplying it to the capacitor (C102); A capacitor (C102) for charging the voltage supplied through the path and supplying it to an auxiliary power source for driving the regulator integrated device (101); A diode (D102) and a capacitor (C103) for rectifying and smoothing the voltage excited by the winding (S) of the transformer (T101) to supply the output voltage (V _out1 ); The output voltage (V _out1) in order to stabilize the output voltage error comparator (102) to the (V _out1) compared to the reference voltage of the internal detecting the error value corresponding thereto and; The first DC / DC converter 100A is configured with a photocoupler 103 for returning error information detected by the error comparator 102 to the regulator integrated device 101, and the first DC / DC converter ( A second DC / DC converter 200A having the same configuration as 100A is connected in parallel to generate an output voltage V _out2 , and the transformer T201 ′ of the second DC / DC converter 200A is configured for auxiliary power. 6 to 10 attached to the operation of the present invention configured to share the voltage output from the winding (D) of the first DC / DC converter (100A), without installing a winding (D) separately When described in detail with reference to as follows.

In the circuit of FIG. 6, the first DC / DC converter 100A generates a fixed level output voltage V _out1 , and the second DC / DC converter 200A generates a variable output voltage V _out2 . An example is a circuit diagram. The level of the output voltage V _out2 is set by the trimmer volume built into the error comparator 102.

In FIG. 6, a power line L601 connected across two DC / DC converters 100A and 200A shows a specific example of the present invention.

That is, the D-winding terminal of the first DC / DC converter 100A is branched and connected to the anode of the rectifying diode D201 of the second DC / DC converter 200A. As a result, the second DC / DC converter 200A receives the stabilized D winding voltage from the first DC / DC converter 100A instead of the D winding of its own transformer T201 ', resulting in an existing problem. And cost up are improved. Of course, since the D winding of the transformer T201 'becomes unnecessary, the cost can be reduced by this.

Since the rectifying diode D201 of the second DC / DC converter 200A is reverse biased until the voltage waveform is generated in the D winding in the first DC / DC converter 100A, the state is electrically separated. The starting operation is the same as when used alone in the prior art.

The operation of the second DC / DC converter 200A in FIG. 6 will be described with reference to FIGS. 7A and 7B.

First, the starting resistor R201 and the condenser C202 form a time constant (T2 = R201 · C202) for increasing the voltage of the condenser C202 while supplying a starting current to the regulator integrated device 201. As shown in FIG. 7B, when the value of the time constant T2 is larger (faster) than the time constant value T1 of the first DC / DC converter 100A, the regulator integrated device 201 of the second DC / DC converter 200A is shown. Hunting (hunting) operation to repeat the start and stop is generated in the power supply of the large and small relationship as shown in Figure 7b to avoid this.

In FIG. 7A, the auxiliary power input voltage V _IN2 is started by the same path as the solid line.

Between 0-e: The capacitor C202 is charged with its starting resistor R201, and the section fails to reach starting.

Between e-f: The moment the first DC / DC converter 100A is started and the D winding voltage is supplied, it is not started yet.

Between f-g: It is charged by the starting resistor R201, and reaches the target starting voltage.

Between g-h: It becomes an operation state and the load current of the regulator integrated element 201 increases (30 mA), and voltage falls.

After h: The operation state is maintained without dropping until stopped by the voltage supplied from the first DC / DC converter 100A.

That is, it can be seen that after the first DC / DC converter 100A is started, the second DC / DC converter 200A is started to maintain an operating state.

In addition, the case in which the first DC / DC converter 100A fails to start for some reason follows the dotted line path of FIG. 7A.

0-i: When the voltage is not supplied from the first DC / DC converter 100A and the second DC / DC converter 200A is started by rain by its starting resistor R201.

After this, the hunting as shown in FIG. 7B is reached.

0-j: Similarly, the battery is only charged by its own starting resistor R201, but is absorbed by the starting current of the regulator integrated element 201 and fails to reach the desired starting voltage level.

After this, no hunting occurs in the second DC / DC converter 200A.

The two paths of 0-i and 0-j can be selected according to the selection of the starting resistor R201 and the capacitor C202, and 0-j when an abnormality of the first DC / DC converter 100A is expected. Select.

The above description is for the case where the two regulator integrated devices 101 and 201 have the same characteristics (the starting voltage and the stopping voltage value are the same) so that the starting sequence is fixed. This will be described with reference to FIGS. 8 to 10.

8A-10A schematically illustrate the results of the auxiliary power supply of the two circuits, and FIGS. 8B-10B show voltage changes for explaining the starting operation.

8A and 9A show a case in which the specifications of the two regulator integrated devices 101 and 201 are different, and a second DC / DC converter with respect to the regulator integrated device 101 of the first DC / DC converter 100A is shown. When the starting voltage of the regulator integrated device 201 of 200A is low, FIG. 8A is selected, and in the reverse case, FIG. 9A is selected.

As described above, in the present invention, the two regulator integrated devices 101 and 201 may have different specifications. For this purpose, as illustrated in FIGS. 8A and 9A, the transformer T101 may be used in the first DC / DC converter 100A. Intermediate taps were installed on the D-window of to make it possible to obtain a suitable voltage.

Next, FIG. 10A illustrates an example in which it is necessary to simultaneously start up the first DC / DC converter 100A and the second DC / DC converter 200A. The first DC / DC converter 100A is illustrated in FIG. The supply voltage from the second DC / DC converter 200A is equal to or higher than the starting voltage level of the second DC / DC converter 200A so as to be suitable for continuing startup and operation regardless of the starting resistance in the second DC / DC converter 200A. In this case, the existing starting resistors and capacitors are also unnecessary.

As described above, in the present invention, the countermeasure which is effective when the D winding voltage of the second DC / DC converter 200A is not stabilized is basically provided. Systemization such as continuous output is included.

As described above in detail, the present invention utilizes the auxiliary power output from the D winding of the first DC / DC converter as the auxiliary power of the second DC / DC converter, thereby ensuring a stable auxiliary power, thereby improving the use efficiency of components. In addition to these improvements, there are cost savings. In addition, since the limitation of the characteristics of the D winding with respect to the auxiliary power supply is eliminated, there is an effect that can be easily coped when the input and output voltage is variable. In addition, when a multi-power output must be generated continuously, it is automatically included in the design, thereby improving the stability of the entire power supply system.

Claims (4)

It is provided with main windings (P) and (S) for converting the DC input voltage (V _in ) to the desired level of voltage and delivering it to the output stage, and has a secondary power winding (D) for supplying an internal driving voltage. One trans (T101); A transistor FET101 for interrupting the current of the main winding P; A regulator integrated device (101) for controlling the on and off of the transistor (FET101) based on the error information returned and the current flowing through the transistor (FET101); A starting resistor R101 for supplying the input voltage V _in to a capacitor C102; A diode (D101) for rectifying the voltage output from the winding (D) and supplying it to the capacitor (C102); A capacitor (C102) for charging the voltage supplied through the path and supplying it to an auxiliary power source for driving the regulator integrated device (101); The first DC / DC converter 100A includes a diode D102 and a capacitor C103 for rectifying and smoothing the voltage excited by the winding S of the transformer T101 to supply the output voltage V _out1 . And an auxiliary power supply to the transformer T201 'of the second DC / DC converter 200A which generates an output voltage V _out2 by sharing an input voltage V _in with the first DC / DC converter 100A. Multi-circuit switching power supply, characterized in that configured to share the voltage output from the winding (D) of the transformer (T101) in the first DC / DC converter (100A) without providing a winding (D) for supplying . According to claim 1, characterized in that the intermediate tap is provided in the winding (D) of the transformer (T101) and configured to supply the output voltage of the intermediate tap to the auxiliary power supply of the first DC / DC converter (100A) as necessary. Multi-circuit switching power supply. According to claim 1, characterized in that the intermediate tap is provided in the winding (D) of the transformer (T101) and configured to supply the output voltage of the intermediate tap to the auxiliary power supply of the second DC / DC converter (200A) as necessary. Multi-circuit switching power supply. The method of claim 1, wherein the voltage output from the winding (D) of the transformer (T101) is configured to supply the regulator integrated device (201) of the second DC / DC converter (200A) directly through one diode (D201). Multi-circuit switching power supply characterized in that.