Power supply and applicable power supply system thereof

Abstract

The invention relates to a power supply, comprising: an input terminal selectively receiving an input voltage; an output terminal; the main circuit is electrically connected between the input end and the output end; the ORing field effect transistor is electrically connected between the output end and the main circuit; the driving circuit is electrically connected to the control end of the ORing field effect transistor and is used for outputting a control signal to control the operation of the ORing field effect transistor; the auxiliary switch is electrically connected between the driving circuit and the control end of the ORing field effect transistor; when the power supply is inserted into a system bus of the power supply system and electrically connected with other power supplies in operation in parallel, and the input end of the power supply does not receive input voltage, the auxiliary switch bypasses the control signal, so that the control signal cannot be transmitted to the control end of the ORing field effect transistor, and the ORing field effect transistor is disconnected.

Description

Technical Field

[0001] The present invention relates to a power supply, and more particularly to a power supply capable of reducing system malfunction and improving reliability, and a power supply system applicable thereto. Background Art

[0002] With the development of the electronics industry, power supply systems have been widely used to supply power. A power supply system usually includes multiple power supplies connected in parallel to a system bus. Accordingly, an ORing device with isolation is required between each power supply and the system bus to prevent, for example, reverse current from flowing back from the system bus to the power supply. The ORing device is mostly composed of an ORing field effect transistor. As the output power of the power supply system increases, the loss caused by the voltage drop of the ORing field effect transistor also increases exponentially. Therefore, in order to reduce power loss, it is necessary to start with the on-resistance (Rdson) of the ORing field effect transistor.

[0003] However, the means to reduce power loss at present are nothing more than finding an ORing field effect transistor with lower on-resistance, or using multiple ORing field effect transistors in parallel. However, this method will bring a big problem, that is, when the power supply is inserted into the system bus of the power supply system in an unpowered manner, due to the influence of stray parameters and the speed of insertion, the ORing field effect transistor will malfunction, causing the system voltage of the power supply system to instantly charge the internal capacitor of the unpowered power supply, causing the voltage of the power supply system to drop. In this way, the power supply system is prone to crash or malfunction.

[0004] Although it is possible to try to screen the parameter characteristics of ORing field effect transistors to reduce the probability of false operation, it also brings about restrictions on the use of materials, making it difficult to produce power supplies or power supply systems. In addition, there is also an intervention of the equivalent capacitance between the gate and source of the field effect transistor by adding capacitance between the gate and source of the field effect transistor to reduce the probability of false operation, but this method will also cause the turn-off speed of the ORing field effect transistor to slow down, resulting in reduced reliability of the power supply and power supply system.

[0005] Therefore, how to develop a power supply device and a power supply system applicable thereto that overcome the above-mentioned deficiencies is currently the most urgent issue to be solved. Summary of the invention

[0006] The purpose of the present invention is to provide a power supply and a power supply system applicable thereto. The power supply includes an auxiliary switch connected between a driving circuit and a control end of an ORing field effect transistor. When an unpowered power supply is placed in the power supply system and electrically connected to other operating power supplies, the auxiliary switch is disconnected, turning off the ORing field effect transistor. Thus, the power supply and the power supply system applicable thereto of the present invention can reduce system malfunctions and improve reliability.

[0007] To achieve the aforementioned purpose, a preferred embodiment of the present invention provides a power supply, comprising: an input terminal for selectively receiving an input voltage; an output terminal; a main circuit electrically connected between the input terminal and the output terminal for converting the input voltage received by the input terminal into an output voltage; an ORing field effect transistor electrically connected between the output terminal and the main circuit; a driving circuit electrically connected to the control terminal of the ORing field effect transistor for detecting the current output by the main circuit and outputting a control signal according to the detection result to correspondingly control the operation of the ORing field effect transistor; and an auxiliary switch electrically connected between the driving circuit and the control terminal of the ORing field effect transistor; wherein when the power supply is plugged into a system bus of a power supply system and electrically connected in parallel with other operating power supplies, and the input terminal of the power supply does not receive an input voltage, the auxiliary switch bypasses the control signal output by the driving circuit, so that the control signal cannot be transmitted to the control terminal of the ORing field effect transistor, so that the ORing field effect transistor is disconnected.

[0008] To achieve the aforementioned purpose, another preferred embodiment of the present invention provides a power supply system, comprising: a system bus; a plurality of power supplies, each of which is selectively plugged into the system bus, and each of which comprises: an input terminal selectively receiving an input voltage; an output terminal; a main circuit electrically connected between the input terminal and the output terminal, for converting the input voltage received by the input terminal into an output voltage; an ORing field effect transistor electrically connected between the output terminal and the main circuit; a driving circuit electrically connected to the control terminal of the ORing field effect transistor, for detecting the current output by the main circuit, and outputting a control signal according to the detection result to correspondingly control the operation of the ORing field effect transistor; and an auxiliary switch electrically connected between the driving circuit and the control terminal of the ORing field effect transistor; wherein when any power supply that does not receive the input voltage is plugged into the system bus of the power supply system to form a rear plug-in power supply, and is electrically connected in parallel with other power supplies that are in operation, the auxiliary switch of the rear plug-in power supply bypasses the control signal output by the driving circuit, so that the control signal cannot be transmitted to the control terminal of the ORing field effect transistor, so that the ORing field effect transistor is disconnected. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A schematic diagram of the structure of a power supply system of a preferred embodiment of the present invention;

[0010] Figure 2 for Figure 1 A schematic diagram of the structure of any power supply in the power supply system shown;

[0011] Figure 3 The power supply for the conventional power supply system is not used Figure 2 A schematic diagram of the timing of the output voltage of each power supply and the voltage of the ORing field effect transistor when the auxiliary switch is turned on; and

[0012] Figure 4 for Figure 1 A schematic diagram of the timing between the output voltage of each power supply of the power supply system and the voltage of the ORing field effect transistor; and

[0013] Figure 5 for Figure 2 FIG. 1 is a schematic structural diagram of another variation of an auxiliary switch of a power supply.

[0014] Description of Figure Numbers:

[0015] 1: Power supply system

[0016] 2: Power supply

[0017] 3: System bus

[0018] Vin: Input voltage

[0019] 20: Main circuit

[0020] 21: ORing Field Effect Transistor

[0021] 22: Auxiliary switch

[0022] 23: Driving circuit

[0023] T: Time

[0024] D: diode

[0025] Vcc: voltage source

[0026] B: PNP transistor DETAILED DESCRIPTION

[0027] Some typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various variations in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations therein are essentially for illustrative purposes, rather than for limiting the present invention.

[0028] See also Figure 1 and Figure 2 ,in Figure 1 is a schematic diagram of the structure of the power supply system of the preferred embodiment of the present invention, Figure 2 for Figure 1 The schematic diagram of the structure of any power supply in the power supply system shown. The power supply system 1 of the present case comprises a plurality of power supplies 2 and a system bus 3. The circuit architecture of the plurality of power supplies 2 is the same, and the number of the power supplies 2 can be at least two. Figure 1 Two power supplies 2 are shown in the following. Figure 1 The power supply 2 located at the top is temporarily designated as the first power supply 2. Figure 1 The power supply 2 at the bottom is tentatively designated as the second power supply 2. The first power supply 2 and the second power supply 2 can be selectively plugged into the system bus 3 respectively. It is tentatively designated that the first power supply 2 has been plugged into the system bus 3 and receives the input voltage Vin and operates normally. The second power supply 2 is intended to be plugged into the system bus 3 without receiving the input voltage Vin and is connected in parallel with the first power supply 2. The second power supply 2 can also be called a rear-plug power supply.

[0029] Each power supply 2 includes a main circuit 20, an ORing field effect transistor 21, an auxiliary switch 22 and a driving circuit 23. The input end of the main circuit 20 is electrically connected to the input end of the power supply 2, and can selectively receive an input voltage Vin, and convert the input voltage Vin into an output voltage to be output at the output end of the main circuit 20.

[0030] The ORing field effect transistor 21 includes a first terminal, a second terminal and a control terminal. The first terminal of the ORing field effect transistor 21 is electrically connected to the output terminal of the main circuit 20 , and the second terminal of the ORing field effect transistor 21 is electrically connected to the output terminal of the power supply 2 .

[0031] The driving circuit 23 is electrically connected to the control end of the ORing field effect transistor 21, and is used to detect the current on the output end of the main circuit 20, and output a control signal to the control end of the ORing field effect transistor 21 according to the detection result, so as to control the operation of the ORing field effect transistor 21 accordingly, and then control the ORing field effect transistor 21 to be turned off to prevent, for example, reverse current from flowing back from the system bus 3 to the existing power supply 2, or to control the ORing field effect transistor 21 to be turned off when the power supply 2 is abnormal.

[0032] The auxiliary switch 22 is electrically connected between the driving circuit 23 and the control end of the ORing field effect transistor 21. When the second power supply 2 is to be plugged into the system bus 3 without receiving the input voltage Vin, and then electrically connected to the operating first power supply 2, the auxiliary switch 22 of the second power supply 2 will bypass the control signal output by the driving circuit 23, so that the control signal output by the driving circuit 23 cannot be transmitted to the control end of the ORing field effect transistor 21, thereby disconnecting the ORing field effect transistor 21 of the second power supply 2.

[0033] See also Figure 3 and Figure 4 ,in Figure 3 The power supply for the conventional power supply system is not used Figure 2 The timing diagram of the output voltage of each power supply and the voltage of the ORing field effect transistor when the auxiliary switch is turned on is shown in FIG. Figure 4 for Figure 1 The diagram shows a timing diagram of the output voltage of each power supply of the power supply system and the voltage of the ORing field effect transistor. Figure 3 The first waveform shown is a waveform of an output voltage of the first power supply of a conventional power supply system when the first power supply is plugged into a system bus and receives an input voltage Vin and operates normally. Figure 3 The second waveform shown is a waveform of the output voltage of the second power supply of the conventional power supply system when the second power supply is to be plugged into the system bus without receiving the input voltage Vin. Figure 3 The third waveform shown is a voltage waveform on the ORing field effect transistor of the first power supply of the conventional power supply system. Figure 4 The first waveform shown is a waveform of the output voltage of the first power supply 2 when the first power supply 2 of the power supply system 1 of the present invention is plugged into the system bus 3 and receives the input voltage Vin and operates normally. Figure 4 The second waveform shown is a waveform of the output voltage of the second power supply 2 when the second power supply 2 of the power supply system 1 of the present invention is plugged into the system bus without receiving the input voltage Vin. Figure 4 The third waveform shown is the voltage waveform on the ORing field effect transistor 21 of the first power supply 2 of the power supply system 1 of the present invention. At time T, when the second power supply of the conventional power supply system is to be plugged into the system bus without receiving the input voltage Vin, the output voltage of the second power supply will be pulled down, and the voltage on the ORing field effect transistor 21 of the first power supply 2 will be pulled up and malfunction. Figure 4As shown, at time T, when the second power supply 2 of the power supply system 1 of the present invention is to be plugged into the system bus 3 without receiving the input voltage Vin, the auxiliary switch 22 of the second power supply 2 will bypass the control signal output by the driving circuit 23, so that the control signal output by the driving circuit 23 cannot be transmitted to the control end of the ORing field effect transistor 21, thereby disconnecting the ORing field effect transistor 21 of the second power supply 2. In this way, the output voltage of the second power supply 2 can still be maintained at the original output voltage, and the voltage on the ORing field effect transistor 21 of the first power supply 2 is also roughly maintained at the original voltage. Therefore, the insertion of the second power supply 2 will not affect the operation of the first power supply 1. Therefore, there is no need to consider whether the output power of the power supply system 1 increases, the number of ORing field effect transistors connected in parallel, or the parameter characteristics of the ORing field effect transistor. The malfunction of the power supply system 1 of the present invention can be avoided, and the reliability of the power supply system 1 during operation is improved.

[0034] In some embodiments, the auxiliary switch 22 may be formed by a diode D, wherein the anode terminal of the diode D is electrically connected between the driving circuit 23 and the control terminal of the ORing field effect transistor, and the cathode terminal of the diode D is electrically connected to the voltage source Vcc inside the power supply 2, wherein the voltage of the voltage source Vcc is proportional to the input voltage Vin of the power supply 2, and when the power supply 2 does not receive the input voltage Vin, the voltage of the voltage source Vcc is equal to zero. Therefore, when the second power supply 2 of the power supply system 1 of the present case is intended to be plugged into the system bus 3 without receiving the input voltage Vin, at this time, since the voltage of the voltage source Vcc is equal to zero, the control signal output by the driving circuit 23 will be bypassed through the diode D, resulting in the control signal being unable to be transmitted to the control terminal of the ORing field effect transistor 21, so that the ORing field effect transistor 21 of the second power supply 2 is disconnected.

[0035] In some embodiments, when the control signal output by the driving circuit 23 is a high level voltage and the auxiliary switch 22 is turned on, the ORing field effect transistor 21 is turned on, and when the control signal output by the driving circuit 23 is a low level voltage, the ORing field effect transistor 21 is turned off.

[0036] In other embodiments, the auxiliary switch 22 may also be formed by a Zener diode, the anode of the Zener diode is electrically connected between the driving circuit 23 and the control terminal of the ORing field effect transistor, and the cathode of the Zener diode is electrically connected to the voltage source Vcc inside the power supply 2 .

[0037] See also Figure 5 , which is Figure 2FIG. 2 is a schematic diagram of another variation of the auxiliary switch of the power supply shown in FIG. In some embodiments, the auxiliary switch 22 may also be formed by a transistor, for example Figure 5 As shown, the auxiliary switch 22 can be formed by a PNP transistor B. The base of the PNP transistor B is electrically connected to the voltage source Vcc inside the power supply 2, the emitter of the PNP transistor B is electrically connected between the driving circuit 23 and the control terminal of the ORing field effect transistor, and the collector of the PNP transistor B is grounded.

[0038] In summary, the present invention provides a power supply and a power supply system applicable thereto, wherein when the second power supply of the power supply system of the present invention is to be plugged into the system bus without receiving an input voltage, the auxiliary switch 22 of the second power supply 2 will bypass the control signal output by the driving circuit 23, so that the control signal output by the driving circuit cannot be transmitted to the control end of the ORing field effect transistor, thereby disconnecting the ORing field effect transistor of the second power supply. In this way, the output voltage of the second power supply 2 can still be maintained at the original output voltage, and the voltage on the ORing field effect transistor of the first power supply is also substantially maintained at the original voltage. Therefore, the insertion of the second power supply will not affect the operation of the first power supply. Therefore, there is no need to consider whether the output power of the power supply system increases, the number of ORing field effect transistors connected in parallel, or the parameter characteristics of the ORing field effect transistor. The malfunction of the power supply system of the present invention can be avoided, and the reliability of the power supply system during operation is improved.

Claims

1. A power supply, comprising: An input terminal selectively receiving an input voltage; Output terminal; A main circuit, electrically connected between the input end and the output end, for converting the input voltage received by the input end into an output voltage; An ORing field effect transistor electrically connected between the output terminal and the main circuit; A driving circuit, electrically connected to the control terminal of the ORing field effect transistor, for detecting the current output by the main circuit and outputting a control signal according to the detection result to correspondingly control the operation of the ORing field effect transistor; as well as an auxiliary switch, electrically connected between the driving circuit and the control terminal of the ORing field effect transistor; When the power supply is plugged into the system bus of the power supply system and electrically connected in parallel with other operating power supplies, and the input end of the power supply does not receive the input voltage, the auxiliary switch bypasses the control signal output by the drive circuit, so that the control signal cannot be transmitted to the control end of the ORing field effect transistor, thereby disconnecting the ORing field effect transistor.

2. The power supply according to claim 1, wherein the auxiliary switch comprises a diode, an anode terminal of the diode is electrically connected between the drive circuit and the control terminal of the ORing field effect transistor, and a cathode terminal of the diode is electrically connected to a voltage source inside the power supply, wherein a voltage of the voltage source is proportional to an input voltage of the power supply, and when the power supply does not receive the input voltage, the voltage of the voltage source is equal to zero.

3. The power supply according to claim 1, wherein the auxiliary switch comprises a Zener diode, an anode terminal of the diode is electrically connected between the drive circuit and the control terminal of the ORing field effect transistor, and a cathode terminal of the diode is electrically connected to a voltage source inside the power supply, wherein a voltage of the voltage source is proportional to an input voltage of the power supply, and when the power supply does not receive the input voltage, the voltage of the voltage source is equal to zero.

4. The power supply according to claim 1, wherein when the control signal output by the driving circuit is a high level voltage and the auxiliary switch is turned on, the ORing field effect transistor is turned on, and when the control signal output by the driving circuit is a low level voltage, the ORing field effect transistor is turned off.

5. The power supply according to claim 1, wherein the auxiliary switch comprises a PNP transistor, the base of the PNP transistor is electrically connected to a voltage source inside the power supply, the emitter of the PNP transistor B is electrically connected between the drive circuit and the control end of the ORing field effect transistor, and the collector of the PNP transistor is grounded.

6. A power supply system, comprising: System bus; A plurality of power supplies, each of which is selectively plugged into the system bus, and each of which comprises: An input terminal selectively receiving an input voltage; Output terminal; A main circuit, electrically connected between the input end and the output end, for converting the input voltage received by the input end into an output voltage; An ORing field effect transistor electrically connected between the output terminal and the main circuit; A driving circuit, electrically connected to the control terminal of the ORing field effect transistor, for detecting the current output by the main circuit and outputting a control signal according to the detection result to correspondingly control the operation of the ORing field effect transistor; as well as an auxiliary switch, electrically connected between the driving circuit and the control terminal of the ORing field effect transistor; When any of the power supplies that do not receive the input voltage is plugged into the system bus of the power supply system to form a rear-plug power supply and is electrically connected in parallel with the other power supplies that are in operation, the auxiliary switch of the rear-plug power supply bypasses the control signal output by the drive circuit, so that the control signal cannot be transmitted to the control end of the ORing field effect transistor, thereby disconnecting the ORing field effect transistor.

7. The power supply system according to claim 6, wherein the auxiliary switch comprises a diode, an anode terminal of the diode is electrically connected between the drive circuit and the control terminal of the ORing field effect transistor, and a cathode terminal of the diode is electrically connected to a voltage source inside the power supply, wherein the voltage of the voltage source is proportional to the input voltage of the power supply, and when the power supply does not receive the input voltage, the voltage of the voltage source is equal to zero.

8. The power supply system according to claim 6, wherein the auxiliary switch comprises a Zener diode, an anode terminal of the diode is electrically connected between the drive circuit and the control terminal of the ORing field effect transistor, and a cathode terminal of the diode is electrically connected to a voltage source inside the power supply, wherein a voltage of the voltage source is proportional to an input voltage of the power supply, and when the power supply does not receive the input voltage, the voltage of the voltage source is equal to zero.

9. The power supply system according to claim 6, wherein when the control signal output by the driving circuit is a high level voltage and the auxiliary switch is turned on, the ORing field effect transistor is turned on, and when the control signal output by the driving circuit is a low level voltage, the ORing field effect transistor is turned off.

10. The power supply system according to claim 6, wherein the auxiliary switch comprises a PNP transistor, the base of the PNP transistor is electrically connected to a voltage source inside the power supply, the emitter of the PNP transistor B is electrically connected between the drive circuit and the control end of the ORing field effect transistor, and the collector of the PNP transistor is grounded.

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