Power supply circuit module and priority-based power supply switching circuit and method

Abstract

The invention relates to the technical field of power supply, and discloses a power supply circuit module, a priority-based power supply switching circuit and a priority-based power supply switching method. The power supply circuit module comprises a relay which is provided with a control coil, a normally closed contact and a normally open contact; the coil control branch circuit is connected with the control coil in series, is used for connecting a power supply in series, and comprises a first cascade port connected between the power supply and the control coil in series; the power supply branch circuit is connected in series with the normally open contact and is connected in series between a power supply and an electricity load; the second cascade port is connected with the normally-closed contact in series, and the second cascade port is used for being connected with the first cascade port of another power supply circuit module; the priority-based power supply switching circuit comprises a plurality of power supply circuit modules which are cascaded in sequence; according to the invention, power supply of the power supply to the load can be well realized.

Description

Technical Field

[0001] The present invention relates to the field of power supply technology, and in particular to a power supply circuit module, a priority-based power supply switching circuit and a method. Background Art

[0002] When there are multiple power supplies in a system that supply power to the load simultaneously or alternately, a power switching circuit is required to switch between different power supplies to solve the problem of multiple competing power supplies. For example, in a mobile device, when the main battery is exhausted or the voltage is insufficient, it automatically switches to the backup battery.

[0003] In the existing technology, there is a multi-channel competitive power supply solution based on diodes, which has a simple circuit structure, low cost, does not require complex control circuits, and is relatively easy to implement; but the voltage drop of the diode will cause a certain power loss, making it difficult to achieve accurate power switching control. Another example is the multi-channel competitive power supply based on comparators and relays, which can control the power switching point more accurately and has high switching accuracy. The on-resistance of the relay is small and the power loss is relatively low, but the circuit is relatively complex and the cost is high. In addition, the multi-channel competitive power supply solution based on a dedicated power management chip has high integration and powerful functions, can implement complex power management strategies, and has fast switching speed, high efficiency, and good protection functions, such as overvoltage and overcurrent protection. However, the cost of this solution is relatively high, and the selection and application requirements of the chip are high, which requires certain technical experience. Summary of the invention

[0004] The present invention provides a power supply circuit module, a priority-based power supply switching circuit and a method, which can overcome certain or some defects of the prior art.

[0005] The power supply circuit module according to the present invention comprises: A relay having a control coil, a normally closed contact and a normally open contact; A coil control branch connected in series with the control coil, which is used to be connected in series with the power supply, and includes a first cascade port connected in series between the power supply and the control coil; A power supply branch connected in series with the normally open contact, the power supply branch being connected in series between the power supply source and the power load; and A second cascade port connected in series with the normally closed contact, the second cascade port being used to access a first cascade port of another power supply circuit module.

[0006] Based on the above, the present invention can better realize the power supply of the power supply to the load. In addition, it can also better realize the topology according to the power supply priority order through the modular power supply circuit. The topology only needs to connect the cascade ports of each module; the modular design can be compatible with the upward and downward priorities; the priority can be automatically selected according to the topology of the circuit without the need to separately detect the quality of each power supply.

[0007] Preferably, a time delay branch is included, and the time delay branch is used to be connected in parallel with the control coil, so that the normally open contact of the relay can be delayed when it is closed.

[0008] Preferably, the delay branch includes an energy storage capacitor C1, and the rated capacity of the energy storage capacitor C1 is C, where C= , the rated voltage of the energy storage capacitor C1 is greater than 1.4Ue, where P is the rated power consumption of the relay, t is the action time of the normally closed contact or the normally open contact, UMAX is the pull-in voltage of the normally open contact, and Ue is the driving voltage of the relay. Therefore, the energy storage capacitor C1 can better protect the circuit.

[0009] Preferably, a freewheeling diode D1 is included, which is connected in parallel with the energy storage capacitor C1. Therefore, the freewheeling diode D1 can better protect the circuit. Preferably, it comprises a voltage-dividing circuit arranged between the power supply and the ground terminal, and the voltage-dividing circuit comprises a voltage-dividing resistor R1 and a voltage-dividing resistor R2 connected in series.

[0010] Preferably, a sampling port is connected between the voltage-dividing resistor R1 and the voltage-dividing resistor R2.

[0011] Based on the above, the present invention can better implement circuit sampling.

[0012] According to the priority-based power supply switching circuit of the present invention, it includes a plurality of power supply circuit modules cascaded in sequence, and the power supply circuit module adopts any of the power supply circuit modules described above.

[0013] Based on the above, the present invention can preferably selectively switch to the power supply with the highest priority among the power supplies currently supplying power to meet the power supply requirements according to the priority of the power supply corresponding to each power supply circuit module, such as the priority determined by factors such as the voltage, current size and stability of the power supply, and when the number or type of power supplies are large, the present invention can complete the switching between multiple power supplies without a comparator, and the circuit is simple to implement.

[0014] Preferably, a coding circuit is included, and the coding circuit is used to be connected to the multiple power supply circuit modules at the same time, so that the power supply corresponding to the multiple power supply circuit modules can be encoded preferably.

[0015] Preferably, the encoding circuit includes an encoding chip U1.

[0016] Preferably, the encoding chip U1 has an input pin and an output pin for accessing the controller, so that the encoding of the power supply in the power supply state can be output to the controller in a better manner.

[0017] According to the priority-based power supply switching method of the present invention, it includes using any of the above-mentioned power supply switching circuits to perform power supply switching. Therefore, it is possible to better realize the power supply of the power supply to the load. In addition, it is also possible to better realize the topology according to the power supply priority order through the modular power supply circuit, and the topology only needs to connect the cascade ports of each module. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a circuit diagram of a power supply circuit module of Example 1; Figure 2 is a circuit block diagram of a priority-based power supply switching circuit of Example 2; Figure 3 is a circuit diagram of another power supply circuit module of Example 2; Figure 4 This is a circuit diagram of the encoding circuit of Example 2. DETAILED DESCRIPTION

[0019] In order to further understand the content of this embodiment, this embodiment is described in detail in conjunction with the embodiment. It should be understood that the embodiment is only used to explain this embodiment but not to limit it.

[0020] Example 1 like Figure 1 As shown, this embodiment provides a circuit diagram of a power supply circuit module, which includes: A relay having a control coil, a normally closed contact and a normally open contact; A coil control branch connected in series with the control coil, which is used to be connected in series with the power supply, and includes a first cascade port connected in series between the power supply and the control coil; A power supply branch connected in series with the normally open contact, the power supply branch being connected in series between the power supply source and the power load; and A second cascade port connected in series with the normally closed contact, the second cascade port being used to access a first cascade port of another power supply circuit module.

[0021] Based on the above, this embodiment can better realize the power supply of the power supply to the load. In addition, it can also better realize the topology according to the power supply priority order through the modular power supply circuit. When topologically, it is only necessary to connect the cascade ports of each module; the modular design can be compatible with the upward and downward priorities; the priority can be automatically selected according to the topology of the circuit without the need to separately detect the quality of each power supply.

[0022] In this embodiment, a time delay branch is included, and the time delay branch is used to be connected in parallel with the control coil, so that the normally open contact of the relay can be delayed when it is closed.

[0023] In this embodiment, the delay branch includes an energy storage capacitor C1, and the rated capacity of the energy storage capacitor C1 is C, where C= , the rated voltage of the energy storage capacitor C1 is greater than 1.4Ue, where P is the rated power consumption of the relay, t is the action time of the normally closed contact or the normally open contact, UMAX is the pull-in voltage of the normally open contact, and Ue is the driving voltage of the relay. Therefore, the energy storage capacitor C1 can better protect the circuit.

[0024] In this embodiment, a freewheeling diode D1 is included, which is connected in parallel with the energy storage capacitor C1, so that the freewheeling diode D1 can better protect the circuit.

[0025] In this embodiment, a voltage divider circuit is provided between the power supply and the ground terminal. The voltage divider circuit, the control coil and the coil control branch together constitute the input circuit of the relay. The voltage divider circuit includes a voltage divider resistor R1 and a voltage divider resistor R2 connected in series.

[0026] In this embodiment, a sampling port is connected between the voltage-dividing resistor R1 and the voltage-dividing resistor R2.

[0027] Based on the above, this embodiment can better implement circuit sampling.

[0028] Example 2 like Figure 2 As shown, this embodiment provides a priority-based power supply switching circuit, including eight power supply circuit modules and an encoding circuit. The working process of this embodiment is as follows: the front-stage circuit inputs multiple power supplies, and after entering the priority competition power supply circuit, the priority competition power supply circuit determines the priority power supply circuit and outputs it to the load for power supply. At the same time, the competition result is output to the encoding circuit for encoding, and the encoding circuit encodes and outputs it to the controller for control logic processing or protection of the subsequent load circuit.

[0029] Combination Figure 1 , Figure 3 and Figure 4As shown, the following embodiment takes two power supply circuit modules and one encoding chip U1 as an example to analyze the working principle of the priority-based power supply switching circuit. The sampling ports of the two power supply circuit modules are respectively connected to pins 15 and 14 of the encoding chip U1 in a cascade order. If more competitive power supplies are required, only the single circuit needs to be expanded.

[0030] In this embodiment, the two power supply circuit modules are cascaded in such a way that the cascade port H-OUT1 and the cascade port H-IN2 are connected; assuming that the circuit starts with the second power supply PWR2 connected and the first power supply PWR1 not connected, at this time, the relay K1 is not actuated, the normally closed contact of the relay K1 is closed (i.e., pins 6 and 7 of the relay K1 remain closed), the voltage of the second power supply PWR2 will be given to the coil of the relay K2 to drive the relay K2 to actuate, and the voltage will be given to the voltage-dividing resistors R3 and R4 to pull up PWR-WK2. After the relay K2 is actuated, the contacts of pins 3 and 4 of the relay K2 will be closed, and the second power supply PWR2 will be output to the PWR-OUT connected to the load; the normally closed contact of the relay K2 will be disconnected (i.e., pins 6 and 7 of the relay K2 are disconnected), and the power supply of the lower circuit will be turned off.

[0031] When the second power supply PWR2 supplies power, after the first power supply PWR1 is connected, the coil of relay K1 is energized, and the normally closed contact of the driving relay K1 is disconnected (that is, pin 6 and pin 7 of relay K1 are disconnected), and the pin 3 and pin 6 contacts of relay K1 are swung from pin 2 and pin 7 to pin 4 and pin 5 respectively. There will be a state in which the pin 3 and pin 6 contacts have been separated from the pin 2 and pin 7 contacts but have not yet reached the pin 4 and pin 5 contacts. At this time, the voltage of the first power supply PWR1 cannot supply power to the load through the pin 4 contact of relay K1 through PWR-OUT, and the driving voltage of relay K2 has been turned off by the pin 7 contact of relay K1. If relay K2 is immediately actuated at this time, the power supply of the second power supply PWR2 to the load through the pin 4 contact of relay K2 will also be immediately cut off, and the power supply of the load circuit will be temporarily interrupted.

[0032] Therefore, in some places with high power supply requirements, that is, places where it is necessary to achieve the requirements of non-inductive (i.e., no power interruption) switching of multiple power supplies, in this embodiment, a delay circuit can also be set at the control coil of the relay, and after the control circuit of the relay K2 is cut off, it can still maintain at least the action time of the pin 3 of the relay K2 swinging from the pin 2 to the pin 4. This embodiment adopts the method of adding energy storage capacitors to the relay to realize the shutdown of the delay relay K2, which is as follows: Multi-stage power supplies are mostly powered by positive power supplies. Considering that the power ground plane may cause noise fluctuations due to extreme load changes, resulting in malfunction of the non-polar coil, this embodiment uses a polar relay and uses an electrolytic capacitor to store energy for the relay. Since the relay is an inductive element, when the driving power is cut off, an instantaneous reverse driving voltage will be generated at both ends of the relay coil, which will cause reverse breakdown of the electrolytic capacitor. Therefore, a freewheeling diode is added to absorb the reverse electromotive force to protect the electrolytic capacitor.

[0033] Assume that the parameters of the selected relay are: driving voltage is Ue (V), pull-in voltage is UMAX (V), and release voltage is UMIN (V); rated power consumption is P (W); action and release time is t (s); to ensure the inductive switching of the power supply, it is required that the power supply circuit with high priority is connected and the power supply circuit with low priority is cut off after t time; reflected on the relay driving branch, it is required that within t time, the voltage across the relay corresponding to the power supply with low priority should be greater than UMIN. Because of the existence of the freewheeling diode, a current spike caused by reverse electromotive force will appear at the moment when the driving voltage is turned off, resulting in the loss of energy of the relay core and the core loss caused by the long-term conduction and heating of the relay coil. This part of the loss needs to be compensated by the energy storage capacitor. Therefore, the pull-in voltage of the relay is selected as the maintenance voltage within t time.

[0034] Considering the manufacturing deviation of the relay, the error limit of K1's pull-in time and K2's release time is 0.3t, so we choose to add 0.5t of time redundancy; therefore, the capacitor energy storage value during the relay switching time should be: W=1.5×P×t; the capacitance value of the capacitor should be: C= ;The capacitor voltage value should be greater than 1.4Ue.

[0035] Based on the above, this embodiment can selectively switch and seamlessly switch to the highest priority power supply according to the priority of the power supply, such as the voltage, current and stability of the power supply when multiple power supplies are supplying power simultaneously.

[0036] In this embodiment, a coding circuit is included, and the coding circuit is used to be connected to a plurality of the power supply circuit modules at the same time, so that the power supply corresponding to the plurality of power supply circuit modules can be preferably coded.

[0037] Combination Figure 4 As shown, in this embodiment, the encoding circuit includes an encoding chip U1, and the model of the encoding chip U1 can be 74LS138, 74LS139, CD4514B or CD4017B.

[0038] In this embodiment, the encoding chip U1 has an output pin for accessing the controller and an input pin for accessing the sampling port. Therefore, it is possible to output the encoding of the power supply in the power supply state to the controller. Therefore, it is possible to better monitor the power supply.

[0039] Example 3 This embodiment provides a priority-based power supply switching method, which uses any power supply switching circuit described in the above embodiment 2 to perform power supply switching. Therefore, it is possible to better achieve selective switching when multiple power supplies are powered simultaneously and to switch to the power supply with the highest priority without feeling. In addition, it is also possible to better achieve topology according to the priority order of the power supplies through a modular power supply circuit, and the topology only needs to connect the cascade ports of each module.

[0040] It is easy to understand that those skilled in the art can combine, split, reorganize, etc. the embodiments of the present application to obtain other embodiments based on one or several embodiments provided in the present application, and these embodiments do not exceed the protection scope of the present application.

[0041] The present invention and its implementation methods are described schematically above, and the description is not restrictive. The embodiments shown in the embodiments are only part of the implementation methods of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by the embodiments and designs a structure and an implementation method similar to the technical solution without creativity without departing from the purpose of the invention, they should all fall within the protection scope of the present invention.

Claims

1. A power supply circuit module, characterized in that: include: A relay having a control coil, a normally closed contact and a normally open contact; A coil control branch connected in series with the control coil, which is used to be connected in series with the power supply, and includes a first cascade port connected in series between the power supply and the control coil; A power supply branch connected in series with the normally open contact, the power supply branch being connected in series between the power supply source and the power load; and A second cascade port connected in series with the normally closed contact, the second cascade port being used to access a first cascade port of another power supply circuit module.

2. The power supply circuit module according to claim 1, characterized in that: It includes a time delay branch, which is used for being connected in parallel with the control coil.

3. The power supply circuit module according to claim 1, characterized in that: The delay branch includes the energy storage capacitor C1, and the rated capacity of the energy storage capacitor C1 is C, where C= , the rated voltage of the energy storage capacitor C1 is greater than 1.4Ue, where P is the rated power consumption of the relay, t is the action time of the normally closed contact or the normally open contact, UMAX is the pull-in voltage of the normally open contact, and Ue is the driving voltage of the relay.

4. The power supply circuit module according to claim 3, characterized in that: A freewheeling diode D1 is included, which is used to be connected in parallel with the energy storage capacitor C1.

5. The power supply circuit module according to claim 1, characterized in that: The invention comprises a voltage dividing circuit arranged between a power supply and a ground terminal, wherein the voltage dividing circuit comprises a voltage dividing resistor R1 and a voltage dividing resistor R2 connected in series.

6. The power supply circuit module according to claim 5, characterized in that: A sampling port is connected between the voltage dividing resistor R1 and the voltage dividing resistor R2.

7. A priority-based power supply switching circuit, characterized in that: It comprises a plurality of power supply circuit modules which are cascaded in sequence, and the power supply circuit module adopts the power supply circuit module described in any one of claims 1-6.

8. The power supply switching circuit according to claim 7, characterized in that , including a coding circuit, which is used to connect to the multiple power supply circuit modules at the same time.

9. The power supply switching circuit according to claim 8, characterized in that: The encoding circuit includes an encoding chip U1.

10. The power supply switching circuit according to claim 9, characterized in that: The encoding chip U1 has an input pin and an output pin for accessing a controller.

11. A priority-based power supply switching method, characterized in that: The power supply switching circuit described in any one of claims 7 to 10 is used to perform power supply switching.

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