TW201427243A - Electromagnetic coupling multi-output control circuit - Google Patents

Abstract

An electromagnetic coupling multi-output control circuit is provided with a detection unit, a switching unit and a coupling unit. The coupling unit is coupled to one side of a transformer of a power source driving device for induction to form a second driving voltage provided for the transformer to have multi-output function. The switching unit receives and outputs the second driving voltage to a second driving load, and the detecting unit detects the second driving voltage to form a detection value so that the switching unit analyzes the detection value and switches/outputs the frequency of the second driving voltage to steady the value of the second driving voltage. Thus, while flexibly increasing the number of sets of output voltage of the power source driving device at the same time, the efficacy of low costs and high applicability can be achieved.

Description

Electromagnetic coupling multi-output control circuit

The invention belongs to the technical field of power supply equipment, in particular to an electromagnetic coupling multi-output control circuit which increases the output voltage by using a coupling coil, and then increases the energy by fixing the output voltage value by a voltage-stabilized mode with no inductive duty cycle (Duty) control. Conversion efficiency.

Switch Power Supply (SPS) is commonly available in fly-back, forward, full bridge, half bridge, and push-pull ( Push-pull) and other circuit architectures, with high efficiency, small size, light weight, easy assembly and large output voltage range, can improve the quality of work and are widely used in various electronic devices. A power supply driving device 1 of a display is used as a column. As shown in Fig. 1, a primary side control flyback conversion circuit architecture is employed. The power supply driving device 1 uses a primary side coil (N ₁ ) of the coupling transformer 10 to induce a filtered input current (V _in ) to form a primary side current, and a secondary side coil (N ₂ ) A first driving voltage (V _D1 ) of 5V is induced and outputted by the fluctuation of the primary current, and the other coil (N ₃ ) of the secondary side is also affected by the fluctuation of the current of the primary side to sense the output of 28V. A second driving voltage (V _D2 ) for driving a plurality of light-emitting diodes (LEDs) of the backlight.

However, in response to the LED process error and the variation of the input voltage source, the second driving voltage may be unstable. The power driving device 1 connects the coil (N ₃ ) to a voltage stabilizing control circuit 11 to transmit Boost. One of the control wafers 110 adjusts the frequency required for an inductor 111 and a capacitor 112 to resonate with each other to output a rated voltage value. It can be seen that the power supply driving device 1 needs to add a set of voltage stabilizing control circuits 11 for outputting a plurality of voltages, which results in a complicated structure and high cost, and does not meet economic cost considerations.

In view of this, how to simplify the circuit architecture of the voltage regulator control circuit 11 to reduce the cost while outputting a plurality of sets of stable output voltage functions is the subject of the present invention.

In view of the problems of the prior art, the object of the present invention is to provide an electromagnetic coupling multi-output control circuit for a power supply driving device, which utilizes a coupling effect and a feedback control principle to provide an output voltage that meets a demand and a stable voltage value, so that the elasticity increases the power supply drive. The number of output units of the device is at the same time, which simplifies the overall circuit architecture and reduces the cost.

According to the purpose of the present invention, the electromagnetic coupling multi-output control circuit is provided for use in a power source driving device such as a liquid crystal display, a television or a light-emitting diode lamp, to allow the power source driving device to have multiple sets of output voltages. And the power driving device generates a first driving voltage by using a transformer to generate an input voltage, and outputs the first driving load to the lighting device, wherein the electromagnetic coupling multi-output control circuit is provided with a detecting unit a switching unit and a coupling unit, the coupling unit is electromagnetically coupled to one side of the transformer to induce a second driving voltage, and the switching unit is telecommunicationally connected to the coupling unit, the second driving load of the lighting device, and the detecting unit The switching unit receives and outputs the second driving voltage to the second driving load, and the detecting unit detects the second driving voltage to form a detection value, so that the switching unit analyzes the detection value to switch and output the second driving Frequency of frequency, up to Stabilizing the effect of the second driving voltage.

Wherein, the power driving device is a fly-back, forward, full-bridge, half-bridge or push-pull switching power conversion circuit architecture, and the electromagnetically coupled multi-output control of the electromagnetically coupled complex type of the transformer And a circuit for outputting the second driving voltage of the complex type, the second driving voltages being stable voltage values of different sizes.

In order to enhance the stability of the output voltage, the electromagnetic coupling multi-output control circuit further includes a driving capacitor coupled to the switch and the second driving load to charge and discharge the second driving voltage to provide a stable voltage to the second driving load.

And the coupling unit is a coupling coil, and the detecting unit is a voltage dividing resistor to divide the second driving voltage to form the detection value, or when the second driving load is a parallel multiple use type, The detecting unit is provided with a current matching circuit (Current Matching Circuit) and a minimum voltage detecting circuit. The multi-channel constant current circuit serially connects the second driving loads to obtain a plurality of driving currents, and the lowest voltage detecting circuit is connected to the multi-channel constant current circuit to detect the driving currents to calculate the lowest voltage value. The detected value. In this way, any circuit that converts energy using a coupled transformer can optionally add the present invention to increase the output voltage, and the present invention can adjust components according to the practical requirements of the current or constant voltage control type to meet practical needs and greatly improve applicability. .

The switching unit is provided with an error amplifier, a comparator, a triangular wave generator and a switch, and the switch is provided with a diode, a transistor, a D-type flip-flop and a switch. The positive input end of the error amplifier receives the detected value, the negative input end receives a reference value, and the output end is coupled The negative input of the comparator. The positive input end of the comparator is coupled to the triangular wave generator, the output end is coupled to the input end of the D-type flip-flop, and the output end of the D-type flip-flop is coupled to the trigger end of the switch. The source of the first transistor is coupled to the detecting unit and the second driving load, the drain is coupled to the coupling coil through the diode, and the gate is coupled to one end of the switch. The coupling unit and the second driving load are coupled to each other as an effect of transferring and controlling the actual output voltage of the second driving voltage.

Furthermore, after actual research, it is found that the power supply driving device is provided with a step-down circuit, and the transformer is connected to the transformer and the input voltage is stepped down and outputted to the transformer. The transformer can be selected from components with low withstand voltage characteristics. The cost is reduced, and the input voltage is directly sensed to form the first driving voltage and the second driving voltage without adding an extra energy conversion component, so as to effectively improve the power factor.

In summary, the switching unit and the detecting unit of the present invention enable the power supply driving device to output a plurality of sets of output voltages, and it is not necessary to add a complicated voltage regulating control circuit of the conventional components according to the output of each group, so that the structure is simple. At the same time as the low-cost characteristics, it is easy to flexibly expand the number of output voltage groups according to practical needs. On the other hand, after the actual experiment, it is known that the driving efficiency of the second driving load can reach 82%, which is superior to the driving efficiency of 75% of the conventional architecture, and the virtual power consumption is actually reduced to help save energy.

In order for your review board to have a clear understanding of the contents of the present invention, please refer to the following description for matching drawings.

Please refer to FIGS. 2~5, which is the first embodiment of the preferred embodiment of the present invention. A block diagram of an embodiment, a block diagram and a circuit diagram of a second embodiment, and a circuit diagram of a third embodiment. As shown, the electromagnetic coupling multi-output control circuit 3 is provided in a power source driving device 2, and provides the power source driving device 2 with a plurality of sets of output voltage functions for, for example, a liquid crystal display, a television, or a light-emitting diode. One of the luminaires is used for lighting equipment. The power driving device 2 is provided with a rectifying circuit 20, a boosting circuit 21, and a switching control circuit 22, which can be used, for example, a flyback type, a forward direction, a full bridge type, a half bridge type or a push-pull type. A power conversion circuit having a coupled coil, such as a switching type or an LLC series resonant type, has a power storage unit 220, a control unit 221, and an output unit 222 as a main structure.

Taking the conversion control circuit 22 of the flyback power conversion circuit architecture as an example, the energy storage unit 220 is a transformer 2201 having a primary side coil (N ₁ ) and a secondary side coil (N ₂ ). The unit 221 is provided with a current transistor 2210, a current resistor 2211 and a control chip 2212. The primary side coil is coupled to the current transistor 2210 and the current resistor 2211 and coupled to the control wafer 2212. A first driving load 4 of the lighting device, such as a system processor of a liquid crystal display or a sound effect player of a television, is coupled through the output unit 222. The rectifier circuit 20 is a bridge rectifier circuit coupled to an external power source and the booster circuit 21, and is configured to receive an input voltage of a variable DC by receiving one of the AC input voltages (V _in ). The boosting circuit 21 is a boost-type power factor correction circuit (Boost PFC) coupled to the primary side coil for boosting the input voltage and charging and discharging by a storage capacitor 210 for storing energy of the primary side coil. Primary side current (I ₁ ). Through the principle of electromagnetic induction, the secondary side coil senses the change of the primary side current and then charges and discharges an output capacitor 2220 to form a first driving voltage (V _D1 ) to be supplied to the first driving load 4 for driving operation. Incidentally, the control chip 2212 instantly detects and adjusts the magnitude of the current of the primary side current to control the first driving voltage to exhibit a stable voltage state.

The conversion control circuit 22 is provided with the electromagnetic coupling multi-output control circuit 3, and is provided with a coupling unit 30, a switching unit 31, a detecting unit 32 and a driving capacitor 33, and the coupling unit 31 is a coupling coil (N ₃ And electromagnetically coupling to the side of the transformer 2201, so that when the output capacitor 2220 stores the energy transmitted by the primary side of the transformer 2201, the first driving voltage is induced by the electromagnetic induction principle to form a second driving voltage ( V _D2 ). The switching unit 31 is connected to the coupling unit 31, the detecting unit 32 and a second driving load 5 of the lighting device, such as a light-emitting diode lamp set, for transferring the second driving voltage to the second driving load. After the detection unit 32 detects that the second driving voltage forms a detection value, the switching unit 31 analyzes the detection value and switches the frequency of outputting the second driving voltage to stabilize the output voltage value and improve the working efficiency of the overall circuit. .

In the embodiment, the switching unit 31 is provided with an error amplifier 310, a comparator 311, a triangular wave generator 312 and a switch 313, and the switch 313 is composed of a diode 3130 and a transistor 3131. A D-type flip-flop 3132 and a switch 3133 are formed. The positive input of the error amplifier 310 receives the detected value, the negative input terminal receives a reference value (V _ref ), and the output terminal is coupled to the negative input terminal of the comparator 311. The positive input end of the comparator 311 is coupled to the triangular wave generator 312 to read a triangular wave to obtain an upper limit value and a lower limit value, and an output end of the comparator 311 is coupled to the input end of the D-type flip-flop 3132. The output end of the D-type flip-flop 3132 is coupled to the trigger end of the switch 3133. The gate of the transistor 3131 is coupled to one end of the switch 3133, the source is coupled to the driving capacitor 33, the detecting unit 32 and the second driving load, and the drain is coupled to the coupling coil through the diode 3130. When the D-type flip-flop 3132 triggers the switch 3133 to turn on the transistor 3131, the driving capacitor 33 charges the second driving voltage to provide a constant voltage value to the second driving load 5.

When the second driving load 5 is formed by a plurality of LED groups, that is, the electromagnetic coupling multi-output control circuit 3 is in a constant voltage control mode, the detecting unit 32 is a voltage dividing resistor 320. The second driving voltage is divided to form the detected value. Alternatively, when the second driving load 5 is formed by a plurality of LED groups, that is, the electromagnetic coupling multi-output control circuit 3 is in a constant current control mode, the detecting unit 32 is provided with a multi-channel setting. a current circuit 321 and a minimum voltage detecting circuit 322. The multi-channel constant current circuit 321 is a current mirror circuit and is connected in series with the light emitting diode lamp sets to obtain a plurality of driving electrodes flowing through the light emitting diode lamp sets. Current. The minimum voltage detecting circuit 322 is connected to the multi-channel constant current circuit 321 to detect the driving currents to calculate the detected value with the lowest voltage value.

Thus, if the input voltage is changed by the physical characteristics of each of the light-emitting diodes, the error amplifier 310 compares the detected value with the reference value, and amplifies the error therebetween to form a detection signal for the comparison. The comparator 311 turns on the switch 31 to output the second driving voltage when the detection signal is less than the lower limit value, and turns off the switch 31 to stop outputting the second driving voltage. It can be seen that the present invention adjusts the transistor by feedback of the variation error of the voltage source. The 3131 conduction period achieves the effect of stabilizing the second driving voltage.

Furthermore, when the output voltage of the power source driving device 2 is to be increased, the newly added electromagnetic coupling multi-output control circuit 3 can be directly electromagnetically coupled to the transformer 2201 side as shown in FIG. 6, and the number of different coils is utilized. The coupling unit 30 can obtain the second driving voltages of different voltage values and high stability. Further, the power source driving device 2 is electrically connected between the rectifier circuit 20 and the energy storage unit 220 by a step-down circuit 23 instead of the booster circuit 21. The step-down circuit 23 is a step-down power factor correction circuit (Buck PFC), which receives and steps down the input voltage of the rectifier and outputs it to the transformer 2201, and the experimentally determined that the power factor can be as high as 96%, which is relatively higher than 94% of the power of the booster circuit 21. In this way, the transformer 2201 can directly sense the input voltage of the step-down voltage to form the first driving voltage and the second driving voltage, thereby effectively improving the power factor.

The above description is only illustrative of preferred embodiments and not limiting. Any equivalent modifications or alterations to the spirit and scope of the invention are intended to be included in the scope of the appended claims.

Traditional skill

1‧‧‧Power drive unit

10‧‧‧Coupling transformer

11‧‧‧Regulator control circuit

110‧‧‧Control chip

111‧‧‧Inductance

112‧‧‧ Capacitance

this invention

2‧‧‧Power drive unit

20‧‧‧Rectifier circuit

21‧‧‧Boost circuit

210‧‧‧ storage capacitor

22‧‧‧Conversion control circuit

220‧‧‧ Energy storage unit

2201‧‧‧Transformer

221‧‧‧Control unit

2210‧‧‧current transistor

2211‧‧‧current resistance

2212‧‧‧Control chip

222‧‧‧Output unit

2220‧‧‧ output capacitor

23‧‧‧Buck circuit

3‧‧‧Electromagnetic coupling multi-output control circuit

30‧‧‧Coupling unit

31‧‧‧Switch unit

310‧‧‧Error amplifier

311‧‧‧ comparator

312‧‧‧ Triangle Wave Generator

313‧‧‧Switcher

3130‧‧‧ diode

3131‧‧‧Optoelectronics

3132‧‧‧D type flip-flop

3133‧‧‧Switch

32‧‧‧Detection unit

320‧‧‧voltage resistor

321‧‧‧Multi-channel constant current circuit

322‧‧‧ Lowest voltage detection circuit

33‧‧‧ drive capacitor

4‧‧‧First drive load

5‧‧‧second drive load

Figure 1 is a circuit diagram of a conventional power supply device.

Figure 2 is a block diagram showing a first embodiment of the preferred embodiment of the present invention.

Figure 3 is a block diagram of a second embodiment of the preferred embodiment of the present invention.

Figure 4 is a circuit diagram of a second embodiment of the preferred embodiment of the present invention.

Figure 5 is a circuit diagram of a third embodiment of the preferred embodiment of the present invention.

Figure 6 is a block diagram of a fourth embodiment of the preferred embodiment of the present invention.

2‧‧‧Power drive unit

2201‧‧‧Transformer

2220‧‧‧ output capacitor

3‧‧‧Electromagnetic coupling multi-output control circuit

30‧‧‧Coupling unit

31‧‧‧Switch unit

32‧‧‧Detection unit

4‧‧‧First drive load

5‧‧‧second drive load

Claims (10)

An electromagnetic coupling multi-output control circuit for use in a power driving device such as a liquid crystal display, a television or a lighting device of a light-emitting diode lamp, to allow the power driving device to have a plurality of sets of output voltage functions, and the power source The driving device generates a first driving voltage by using a transformer to generate a first driving voltage, and outputs the first driving load to the first driving load of the lighting device, wherein the electromagnetic coupling multi-output control circuit is provided with a detecting unit, a switching unit and a coupling unit electromagnetically coupled to one side of the transformer to induce a second driving voltage, the switching unit is telecommunicationally connected to the coupling unit, a second driving load of the lighting device, and the detecting unit; And outputting the second driving voltage to the second driving load, and the detecting unit detects the second driving voltage to form a detection value, so that the switching unit analyzes the detection value and switches the frequency of outputting the second driving voltage to Stabilizing the effect of the second driving voltage. The electromagnetic coupling multi-output control circuit according to claim 1, wherein the coupling unit is a coupling coil, and the detecting unit is a voltage dividing resistor, and the second driving voltage is divided to form the detection value. . The electromagnetic coupling multi-output control circuit according to claim 1, wherein the coupling unit is a coupling coil, and the second driving load is a parallel multi-use type, and the detecting unit is provided with a plurality of a channel constant current circuit and a minimum voltage detecting circuit, the multi-channel constant current circuit serially connecting the second driving loads to obtain a plurality of driving currents, and the lowest voltage detecting circuit telecommunications The multi-channel constant current circuit is connected to detect the driving currents to calculate the detected value with the lowest voltage value. The electromagnetic coupling multi-output control circuit according to claim 3, wherein the multi-channel constant current circuit is a current mirror circuit architecture. The electromagnetic coupling multi-output control circuit according to claim 2 or 3, wherein the switching unit is provided with an error amplifier, a comparator, a triangular wave generator and a switch, and the positive input of the error amplifier The end receives the detection value, the negative input end receives a reference value and the output end is coupled to the negative input end of the comparator, and the positive input end of the comparator is coupled to the triangular wave generator and the output end is coupled to the switch, The coupling unit and the second driving load are respectively coupled to the two ends of the switch. The electromagnetic coupling multi-output control circuit according to claim 5, wherein the switch is provided with a diode, a transistor, a D-type flip-flop and a switch, and the transistor has a drain The diode is coupled to the coupling coil, the source is coupled to the detecting unit and the second driving load, and the gate is coupled to one end of the switch; the trigger end of the switch is coupled to the output end of the D-type flip-flop And the input end of the D-type flip-flop is coupled to the output end of the comparator. The electromagnetic coupling multi-output control circuit according to claim 1, wherein the power driving device is a flyback, forward, full bridge, half bridge or push-pull switching power conversion circuit architecture. . The electromagnetic coupling multi-output control circuit according to claim 1, wherein the transformer is electromagnetically coupled to the plurality of types a magnetically coupled multi-output control circuit for outputting the second driving voltage of the complex type, and the second driving voltages are stable voltage values of different magnitudes. The electromagnetic coupling multi-output control circuit according to claim 1, further comprising a driving capacitor coupled to the switch and the second driving load to charge and discharge the second driving voltage to provide a stable voltage to the The second drive load. The electromagnetic coupling multi-output control circuit according to claim 1, wherein the power driving device is provided with a step-down circuit, and the transformer is connected to the transformer to receive and step down the input voltage, and output the transformer to the transformer. The input voltage of the transformer directly inducing the buck forms the first driving voltage and the second driving voltage, thereby improving the power factor.