TW202143626A - Power supply device with dynamic output - Google Patents

Abstract

A power supply device with a dynamic output at least includes bridge rectifier, a transformer, and an output control circuit. The bridge rectifier generates a rectified voltage according to a first input voltage and a second input voltage. The transformer includes a main coil, a first secondary coil, and a second secondary coil. The main coil receives the rectified voltage, and the first secondary coil generates an induced voltage. The output control circuit generates an output current according to the induced voltage. The output control circuit includes a timer switch element coupled to the second secondary coil. If the output current is greater than or equal to a threshold value, the timer switch element may be closed and start to count a predetermined time. When the predetermined time has expired, the timer switch element may be opened, such that the output current can be decreased below the threshold value.

Description

Power supply with dynamic output

The present invention relates to a power supply, and more particularly to a power supply with dynamic output.

According to the 240VA specification set by UL 60950-1 in the United States, it defines that the built-in power supply should not output a large current above 20A for more than 60 seconds, otherwise it will be regarded as a dangerous power source. However, traditional power supplies often fail to meet this safety standard. In view of this, it is necessary to propose a new solution to overcome the difficulties faced by the previous technology.

In a preferred embodiment, the present invention provides a power supply with dynamic output, including: a bridge rectifier that generates a rectified potential based on a first input potential and a second input potential; and a first capacitor that stores the Rectified potential; a transformer including a main coil, a first auxiliary coil, and a second auxiliary coil, wherein the main coil is used to receive the rectified potential, and the first auxiliary coil is used to generate an induced potential; A power switch for selectively coupling the main coil to the ground according to a first pulse width modulation potential; a pulse width modulation integrated circuit to generate the first pulse width modulation potential; and a The output control circuit generates an output current according to the induced potential, and includes a timing switch coupled to the second auxiliary coil; wherein if the output current is greater than or equal to a critical value, the timing switch will be turned on And start to calculate a predetermined time; wherein when the predetermined time expires, the timing switch will be disconnected, so that the output current drops below the critical value.

In order to make the purpose, features and advantages of the present invention more comprehensible, specific embodiments of the present invention are specifically listed below, in conjunction with the accompanying drawings, and are described in detail as follows.

Certain vocabulary is used to refer to specific elements in the specification and the scope of the patent application. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. This specification and the scope of the patent application do not use differences in names as a way to distinguish elements, but use differences in functions of elements as a criterion for distinguishing. The terms "include" and "include" mentioned in the entire specification and the scope of the patent application are open-ended terms and should be interpreted as "including but not limited to". The term "approximately" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range and achieve the basic technical effect. In addition, the term "coupling" includes any direct and indirect electrical connection means in this specification. Therefore, if it is described in the text that a first device is coupled to a second device, it means that the first device can be directly electrically connected to the second device, or indirectly electrically connected to the second device through other devices or connection means. Two devices.

FIG. 1 shows a schematic diagram of a power supply 100 according to an embodiment of the invention. For example, the power supply 100 can be applied to a desktop computer, a notebook computer, or an integrated computer, but it is not limited to this. As shown in Figure 1, the power supply 100 includes: a bridge rectifier 110, a first capacitor C1, a transformer 120, a power switch 130, a pulse width modulation integrated circuit 140, and an output control circuit 150 . It should be noted that although not shown in Figure 1, the power supply 100 may further include other components, such as a voltage regulator or (and) a negative feedback circuit.

The bridge rectifier 110 can generate a rectified potential VR according to a first input potential VIN1 and a second input potential VIN2. Both the first input potential VIN1 and the second input potential VIN2 can come from an external input power source, wherein an AC voltage having any frequency and any amplitude can be formed between the first input potential VIN1 and the second input potential VIN2. For example, the frequency of the AC voltage can be about 50Hz or 60Hz, and the root mean square value of the AC voltage can be about 90V to 264V, but it is not limited to this. The first capacitor C1 can store the rectified potential VR. The transformer 120 includes a main coil 121, a first auxiliary coil 122, and a second auxiliary coil 123. The main coil 121 can be located on one side of the transformer 120, and the first auxiliary coil 122 and the second auxiliary coil 123 can both be located on one side of the transformer 120. The opposite side of the transformer 120. The main coil 121 can be used to receive the rectified potential VR, and in response to the rectified potential VR, the first auxiliary coil 122 can generate an induced potential VS. The power switch 130 selectively couples the main coil 121 to the ground 190 according to a first pulse width modulated potential VA1. For example, if the first pulse width modulation potential VA1 is at a high logic level (for example: logic "1"), the power switch 130 will couple the main coil 121 to the ground 190 (that is, the power switch 130 can approximate In a short-circuit path); on the contrary, if the first pulse width modulation potential VA1 is a low logic level (for example: logic "0"), the power switch 130 will not couple the main coil 121 to the ground 190 (also That is, the power switch 130 can be approximated as an open path). The earth 190 can refer to the earth, or any ground path coupled to the earth, and it is not an internal component of the power supply 100. The pulse width modulation integrated circuit 140 can generate the first pulse width modulation potential VA1. The output control circuit 150 includes a timing switch 152 coupled to the second auxiliary coil 123. The output control circuit 150 generates an output current IOUT according to the induced potential VS. It must be noted that if the output current IOUT is greater than or equal to a critical value ITH, the timing switch 152 will be turned on and start to calculate a predetermined time TD. Then, when the predetermined time TD expires, the timing switch 152 will be turned off, so that the output current IOUT drops below the critical value ITH. Under this design, even if the power supply 100 has a relatively large output current IOUT, its duration will be strictly limited. Therefore, the proposed power supply 100 will meet the 240VA specification stipulated by UL 60950-1 in the United States. .

The following embodiments will introduce the detailed structure and operation of the power supply 100. It must be understood that these drawings and descriptions are only examples, and are not used to limit the scope of the present invention.

FIG. 2 is a schematic diagram of the power supply 200 according to an embodiment of the invention. In the embodiment of Figure 2, the power supply 200 has a first input node NIN1, a second input node NIN2, and an output node NOUT, and includes a bridge rectifier 210, a first capacitor C1, and a transformer 220 , A power switch 230, a pulse width modulation integrated circuit 240, and an output control circuit 250. The first input node NIN1 and the second input node NIN2 of the power supply 200 can receive a first input potential VIN1 and a second input potential VIN2 respectively from an external input power source, wherein the first input potential VIN1 and the second input potential VIN2 An AC voltage with any frequency and any amplitude can be formed between. The output node NOUT of the power supply 200 can output an output current IOUT and an output potential VOUT, where the output potential VOUT can be approximately a DC potential.

The bridge rectifier 210 includes a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4. The anode of the first diode D1 is coupled to the first input node NIN1, and the cathode of the first diode D1 is coupled to a first node N1 to output a rectified potential VR. The anode of the second diode D2 is coupled to the ground 290, and the cathode of the second diode D2 is coupled to the first input node NIN1. The earth 290 can refer to the earth, or any ground path coupled to the earth, and it is not an internal component of the power supply 200. The anode of the third diode D3 is coupled to the second input node NIN2, and the cathode of the third diode D3 is coupled to the first node N1. The anode of the fourth diode D4 is coupled to the ground 290, and the cathode of the fourth diode D4 is coupled to the second input node NIN2.

The first terminal of the first capacitor is coupled to the first node N1 to receive and store the rectified potential VR, and the second terminal of the first capacitor C1 is coupled to the ground 290.

The transformer 220 includes a main coil 221, a first auxiliary coil 222, and a second auxiliary coil 223. The main coil 221 can be located on one side of the transformer 220, and the first auxiliary coil 222 and the second auxiliary coil 223 can both be located on one side of the transformer 220. The opposite side of the transformer 220. The first end of the main coil 221 is coupled to the first node N1 to receive the rectified potential VR, and the second end of the main coil 221 is coupled to a second node N2. The first end of the first auxiliary coil 222 is coupled to a third node N3 to output an induced potential, and the second end of the first auxiliary coil 222 is coupled to a fourth node N4. The first end of the second auxiliary winding 223 is coupled to a fifth node N5, and the second end of the second auxiliary winding 223 is coupled to the fourth node N4.

The power switch 230 includes a first transistor M1, which can be regarded as one of the main switches of the power supply 200. The first transistor M1 can be an N-type MOSFET. The control terminal of the first transistor M1 is used to receive a first pulse width modulation potential VA1, the first terminal of the first transistor M1 is coupled to the ground 290, and the second terminal of the first transistor M1 is Coupled to the second node N2.

The pulse width modulation integrated circuit 240 can generate a first pulse width modulation potential VA1 and a second pulse width modulation potential VA2. For example, both the first pulse width modulated potential VA1 and the second pulse width modulated potential VA2 can be maintained at a fixed level when the power supply 200 is initialized, and can be maintained after the power supply 200 enters the normal use stage. Provide periodic clock waveform. In some embodiments, the first pulse width modulated potential VA1 and the second pulse width modulated potential VA2 have the same waveform, but the phase difference therebetween is approximately equal to 180 degrees.

The output control circuit 250 includes a timing switch 252, a second transistor M2, a third transistor M3, a fourth transistor M4, a fifth diode D5, a sixth diode D6, and a third transistor M3. Seven diode D7, an eighth diode D8, a second capacitor C2, a third capacitor C3, an inductor L1, and a resistor R1. The second transistor M2, the third transistor M3, and the fourth transistor M4 may each be an N-type MOSFET. The control terminal of the second transistor M2 is used to receive the second pulse width modulation potential VA2, the first terminal of the second transistor M2 is coupled to the output node NOUT, and the second terminal of the second transistor M2 is coupled Connected to the third node N3 to receive the induced potential VS.

The timing switch 252 has a judging end, a first connecting end, and a second connecting end. The judging end of the timing switch 252 is coupled to a sixth node N6, and the first connecting end of the timing switch 252 is It is coupled to the fifth node N5, and the second connection end of the timing switch 252 is coupled to a seventh node N7. The timing switch 252 is selectively turned on or off according to the potential V6 at the sixth node N6. For example, if the potential V6 at the sixth node N6 is at a low logic level, the timing switch 252 will be turned off, so that the seventh node N7 and the fifth node N5 will not be coupled to each other. In addition, if the potential V6 at the sixth node N6 is switched from a low logic level to a high logic level, the timing switch 252 will be turned on and start to calculate a predetermined time TD, so that the seventh node N7 and the fifth node N5 are in the aforementioned The predetermined time TD will be coupled to each other; however, after the predetermined time TD expires, the timing switch 252 is disconnected, and the seventh node N7 is no longer coupled to the fifth node N5.

The control end of the third transistor M3 is coupled to the sixth node N6, the first end of the third transistor M3 is coupled to an eighth node N8, and the second end of the third transistor M3 is coupled to the first Seven node N7. The control terminal of the fourth transistor M4 is used to receive the second pulse width modulation potential VA2, the first terminal of the fourth transistor M4 is coupled to a ninth node N9, and the second terminal of the fourth transistor M4 It is coupled to the eighth node N8. The anode of the fifth diode D5 is coupled to the ninth node N9, and the cathode of the fifth diode D5 is coupled to the output node NOUT. The first end of the second capacitor C2 is coupled to the ninth node N9, and the second end of the second capacitor C2 is coupled to the fourth node N4.

The anode of the sixth diode D6 is coupled to the fourth node N4, and the cathode of the sixth diode D6 is coupled to the output node NOUT. The first terminal of the third capacitor C3 is coupled to the output node NOUT, and the second terminal of the third capacitor C3 is coupled to a ground potential VSS (for example, 0V). The first end of the inductor L1 is coupled to the fourth node N4, and the second end of the inductor L1 is coupled to the sixth node N6. The anode of the seventh diode D7 is coupled to the ground potential VSS, and the cathode of the seventh diode D7 is coupled to the sixth node N6. The anode of the eighth diode D8 is coupled to the fourth node N4, and the cathode of the eighth diode D8 is coupled to a tenth node N10. The first end of the resistor R1 is coupled to the tenth node N10, and the second end of the resistor R1 is coupled to the ground potential VSS.

In some embodiments, the power supply 200 can operate in an initial mode, a first mode, a second mode, or a third mode, and the operating principles will be as follows, respectively.

In the initial mode, the power supply 200 has not received the first input potential VIN1 and the second input potential VIN2. At this time, the first transistor M1, the second transistor M2, the third transistor M3, and the fourth transistor M4 All were banned.

In the first mode, the power supply 200 has received the first input potential VIN1 and the second input potential VIN2, and the pulse width modulation integrated circuit 240 generates the first pulse width modulation potential VA1 and the second pulse width modulation The potential VA2 is changed to control the first transistor M1 and the second transistor M2. The output current IOUT flows through the inductor L1, so the inductor L1 starts to store energy. In the first mode, the output current IOUT is less than a critical value ITH, and the potential V6 at the sixth node N6 is relatively low to disable the third transistor M3 and turn off the timing switch 252. At this time, the second capacitor C2 does not store any charge. It must be noted that the seventh diode D7 can prevent the third capacitor C3 from resonating with the inductor L1, thereby increasing the stability of the power supply 200.

In the second mode, the output current IOUT is greater than or equal to the critical value ITH, and the potential V6 at the sixth node N6 is relatively high, so that the third transistor M3 is enabled and the timing switch 252 is temporarily turned on. At this time, the timing switch 252 starts to calculate the aforementioned predetermined time TD. Because the fourth transistor M4 is also switched by the second pulse width modulation potential VA2, the second capacitor C2 will be charged and the potential V9 at the ninth node N9 will be raised. It must be noted that the participation of the second secondary coil 223 in the second mode helps to maintain a relatively large output current IOUT. In addition, the sixth diode D6 and the eighth diode D8 are both disabled in the second mode.

In the third mode, when the predetermined time TD has expired, the timing switch 252 returns to the off state. Without the participation of the second auxiliary coil 223, the output current IOUT will again drop below the critical value ITH. According to the cold order law, the voltage polarity of the inductor L1 will therefore be reversed, so that the sixth diode D6 and the eighth diode D8 can be enabled. At this time, the energy stored on the inductor L1 is quickly released to the ground potential VSS via a first discharge path and a second discharge path, where the first discharge path includes the sixth diode D6 and the third capacitor C3, The second discharge path includes an eighth diode D8 and a resistor R1. After the third mode ends, the power supply 200 can switch back to the second mode again to perform the next cycle.

Fig. 3 shows an output waveform diagram of the power supply 200 according to an embodiment of the present invention, in which the horizontal axis represents time, and the vertical axis represents potential level or current value. According to the measurement result in Figure 3, the output potential VOUT of the power supply 200 is a dynamic output, and every time the output current IOUT of the power supply 200 is greater than or equal to the critical value ITH, its duration will be less than or equal to the timing The predetermined time TD defined by the switch 252. By properly controlling the predetermined time TD, the power supply 200 will not be regarded as a dangerous power source, and can fully comply with the 240VA specification stipulated by UL 60950-1 in the United States.

In some embodiments, the component parameters of the power supply 200 may be as described below. The predetermined time TD of the timing switch 252 may be approximately 10 seconds. The capacitance value of the second capacitor C2 can be between 646 μF and 714 μF, preferably 680 μF. The capacitance value of the third capacitor C3 can be between 646 μF and 714 μF, preferably 680 μF. The inductance value of the inductor L1 can be between 95 μH and 105 μH, preferably 100 μH. The resistance value of the resistor R1 can be between 313.5Ω and 346.5Ω, preferably 330Ω. The switching frequency of the first pulse width modulated potential VA1 and the second pulse width modulated potential VA2 can both be about 65 kHz. The ratio of the number of turns of the primary coil 221 to the first secondary coil 222 can be between 1 and 100, and preferably can be 20. The ratio of the number of turns of the main coil 221 to the second auxiliary coil 223 may be between 1 and 100, preferably 20. The above parameter range is obtained based on the results of many experiments, which helps to optimize the safety margin of the power supply 200.

The present invention proposes a novel power supply with dynamic output. According to actual measurement results, the power supply with the aforementioned design can fully comply with the 240VA specification set by UL 60950-1 in the United States. Since the present invention can effectively improve the safety margin of the power supply, it is very suitable for application in various types of devices.

It is worth noting that the above-mentioned potential, current, resistance value, inductance value, capacitance value, and other component parameters are not limitations of the present invention. The designer can adjust these settings according to different needs. The power supply of the present invention is not limited to the state shown in Figures 1-3. The present invention may only include any one or more of the features of any one or more of the embodiments shown in FIGS. 1-3. In other words, not all the features shown in the figures need to be implemented in the power supply of the present invention at the same time. Although the embodiment of the present invention uses metal oxide half field effect transistors as an example, the present invention is not limited to this. Those skilled in the art can use other types of transistors, such as junction field effect transistors or fins. Type field effect transistors, etc., without affecting the effect of the present invention.

Although the present invention is disclosed as above in a preferred embodiment, it is not intended to limit the scope of the present invention. Anyone who is familiar with the art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, The scope of protection of the present invention shall be subject to those defined by the attached patent scope.

100, 200: power supply 110, 210: Bridge rectifier 120, 220: Transformer 121, 221: main coil 122,222: the first secondary coil 123,223: the second secondary coil 130, 230: power switch 140, 240: Pulse width modulation integrated circuit 150, 250: output control circuit 152,252: Timing switch 190,290: Earth C1: The first capacitor C2: second capacitor C3: third capacitor D1: The first diode D2: The second diode D3: The third diode D4: The fourth diode D5: Fifth diode D6: The sixth diode D7: seventh diode D8: Eighth diode IOUT: output current ITH: critical value L1: Inductor M1: The first transistor M2: second transistor M3: third transistor M4: The fourth transistor N1: the first node N2: second node N3: third node N4: Fourth node N5: fifth node N6: sixth node N7: seventh node N8: The eighth node N9: Ninth node N10: Tenth node NIN1: the first input node NIN2: second input node NOUT: output node R1: resistor TD: established time V6: Potential at the sixth node V9: Potential at the ninth node VA1: first pulse width modulation potential VA2: second pulse width modulation potential VIN1: the first input potential VIN2: second input potential VOUT: output potential VR: Rectified potential VS: induced potential VSS: Ground potential

Figure 1 is a schematic diagram of a power supply according to an embodiment of the invention. FIG. 2 is a schematic diagram of the power supply according to an embodiment of the invention. Figure 3 is a diagram showing the output waveform of the power supply according to an embodiment of the present invention.

100: power supply

110: Bridge rectifier

120: Transformer

121: main coil

122: The first secondary coil

123: The second secondary coil

130: power switch

140: Pulse width modulation integrated circuit

150: output control circuit

152: Timing Switch

190: Earth

C1: The first capacitor

IOUT: output current

TD: established time

VA1: first pulse width modulation potential

VIN1: first input potential

VIN2: second input potential

VR: Rectified potential

VS: induced potential

Claims (10)

A power supply with dynamic output, including: A bridge rectifier generates a rectified potential according to a first input potential and a second input potential; A first capacitor storing the rectified potential; A transformer, including a main coil, a first auxiliary coil, and a second auxiliary coil, wherein the main coil is used to receive the rectified potential, and the first auxiliary coil is used to generate an induced potential; A power switch, which selectively couples the main coil to the ground according to a first pulse width modulation potential; A pulse width modulation integrated circuit to generate the first pulse width modulation potential; and An output control circuit, which generates an output current according to the induced potential, and includes a timing switch coupled to the second auxiliary coil; If the output current is greater than or equal to a critical value, the timing switch will be turned on and start to calculate a predetermined time; When the predetermined time expires, the timing switch will be disconnected, so that the output current drops below the critical value. The power supply according to claim 1, wherein the bridge rectifier includes: A first diode has an anode and a cathode, wherein the anode of the first diode is coupled to a first input node to receive the first input potential, and the first diode of the The cathode is coupled to a first node to output the rectified potential; A second diode having an anode and a cathode, wherein the anode of the second diode is coupled to the ground, and the cathode of the second diode is coupled to the first input node ； A third diode has an anode and a cathode, wherein the anode of the third diode is coupled to a second input node to receive the second input potential, and the third diode of the The cathode is coupled to the first node; and A fourth diode having an anode and a cathode, wherein the anode of the fourth diode is coupled to the ground, and the cathode of the fourth diode is coupled to the second input node ； The first capacitor has a first terminal and a second terminal, the first terminal of the first capacitor is coupled to the first node, and the second terminal of the first capacitor is coupled to the ground . The power supply of claim 2, wherein the main coil has a first end and a second end, the first end of the main coil is coupled to the first node to receive the rectified potential, and the main coil The second end of the coil is coupled to a second node, the first auxiliary coil has a first end and a second end, and the first end of the first auxiliary coil is coupled to a third node to Output the induced potential, the second end of the first auxiliary coil is coupled to a fourth node, the second auxiliary coil has a first end and a second end, the first end of the second auxiliary coil Is coupled to a fifth node, and the second end of the second secondary coil is coupled to the fourth node. The power supply according to claim 3, wherein the power switch includes: A first transistor has a control terminal, a first terminal, and a second terminal, wherein the control terminal of the first transistor is used to receive the first pulse width modulation potential, and the first transistor The first end of the crystal is coupled to the ground, and the second end of the first transistor is coupled to the second node. The power supply according to claim 4, wherein the pulse width modulation integrated circuit further generates a second pulse width modulation potential, and the output control circuit further includes: A second transistor has a control terminal, a first terminal, and a second terminal, wherein the control terminal of the second transistor is used to receive the second pulse width modulation potential, and the second transistor The first terminal of the crystal is coupled to an output node to output the output current, and the second terminal of the second transistor is coupled to the third node to receive the induced potential. The power supply according to claim 5, wherein the timing switch has a judgment terminal, a first connection terminal, and a second connection terminal, and the judgment terminal of the timing switch is coupled to a sixth node, The first connection terminal of the timing switch is coupled to the fifth node, and the second connection terminal of the timing switch is coupled to a seventh node; The timing switch is selectively turned on or off according to the potential at the sixth node. The power supply according to claim 6, wherein the output control circuit further includes: A third transistor has a control terminal, a first terminal, and a second terminal, wherein the control terminal of the third transistor is coupled to the sixth node, and the first terminal of the third transistor The terminal is coupled to an eighth node, and the second terminal of the third transistor is coupled to the seventh node; A fourth transistor has a control terminal, a first terminal, and a second terminal, wherein the control terminal of the fourth transistor is used to receive the second pulse width modulation potential, and the fourth transistor The first end of the crystal is coupled to a ninth node, and the second end of the fourth transistor is coupled to the eighth node; A fifth diode having an anode and a cathode, wherein the anode of the fifth diode is coupled to the ninth node, and the cathode of the fifth diode is coupled to the output node ;as well as A second capacitor has a first terminal and a second terminal, wherein the first terminal of the second capacitor is coupled to the ninth node, and the second terminal of the second capacitor is coupled to the The fourth node. The power supply according to claim 7, wherein the output control circuit further includes: A sixth diode having an anode and a cathode, wherein the anode of the sixth diode is coupled to the fourth node, and the cathode of the sixth diode is coupled to the output node ;as well as A third capacitor having a first terminal and a second terminal, wherein the first terminal of the third capacitor is coupled to the output node, and the second terminal of the third capacitor is coupled to a ground Potential. The power supply according to claim 8, wherein the output control circuit further includes: An inductor has a first end and a second end, wherein the first end of the inductor is coupled to the fourth node, and the second end of the inductor is coupled to the sixth node ;as well as A seventh diode having an anode and a cathode, wherein the anode of the seventh diode is coupled to the ground potential, and the cathode of the seventh diode is coupled to the sixth node . The power supply according to claim 9, wherein the output control circuit further includes: An eighth diode having an anode and a cathode, wherein the anode of the eighth diode is coupled to the fourth node, and the cathode of the eighth diode is coupled to a tenth Node; and A resistor has a first end and a second end, wherein the first end of the resistor is coupled to the tenth node, and the second end of the resistor is coupled to the ground potential.

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