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

Abstract

The utility model relates to the technical field of power supply, and discloses a power supply circuit module and a priority-based power supply switching circuit. 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 utility model, the power supply can supply power to the load well.

Description

TECHNICAL FIELD

[0001] The utility model relates to power supply technology field, concretely relates to a power supply circuit module and the power supply switching circuit based on priority. BACKGROUND

[0002] When multiple power supplies exist in a system and simultaneously or alternately supply power to a load, a power supply switching circuit is needed 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 runs out of power or the voltage is insufficient, it is automatically switched to a backup battery.

[0003] In the prior art, there is a multiple competing power supply scheme based on diodes, which has a simple circuit structure, low cost, does not require a complex control circuit, and is relatively easy to implement. However, there is a voltage drop of the diode, which will cause a certain power loss and make it difficult to achieve precise power switching control. For example, a multiple competing power supply based on comparators and relays can accurately control the power switching point 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 multiple competing power supply scheme based on a dedicated power management chip has high integration, 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 scheme is relatively high, the selection and application of the chip are relatively high, and certain technical experience is required. SUMMARY

[0004] The utility model provides a kind of power supply circuit module, power supply switching circuit and method based on priority, which can overcome certain or some defects of prior art.

[0005] According to the power supply circuit module of the utility model, it comprises:

[0006] A relay having a control coil, a normally closed contact and a normally open contact;

[0007] A coil control branch connected in series with the control coil, for series connection to a power supply, and comprising a first cascade port connected in series between the power supply and the control coil;

[0008] A power supply branch connected in series with the normally open contact, the power supply branch being connected in series between the power supply and a load; and

[0009] A second cascade port connected in series with the normally closed contact, the second cascade port being configured to connect to a first cascade port of another power supply circuit module.

[0010] Based on the above, the utility model can preferably realize the power supply of the power supply to the load, in addition, can preferably realize through the modular power supply circuit, topology is carried out according to power supply priority order, and only needs to connect the cascade port of each module when topologying, the modular design can be compatible with the priority of upward and downward two sides, and the priority selection can be carried out automatically according to the topology of circuit, and each power supply quality does not need to be detected separately.

[0011] As preferred, the time delay branch is connected in parallel with the control coil, so that the relay normally open contact can be delayed to be disconnected when closed.

[0012] As preferred, the time delay branch comprises an energy storage capacitor C1, the rated capacity of the energy storage capacitor C1 is C, wherein C= , the rated voltage of the energy storage capacitor C1 is greater than 1.4Ue, wherein 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, so that the energy storage capacitor C1 can preferably protect the circuit.

[0013] As preferred, a freewheeling diode D1 is connected in parallel with the energy storage capacitor C1, so that the freewheeling diode D1 can preferably protect the circuit.

[0014] As preferred, a voltage dividing circuit is arranged between the power supply and the ground, and the voltage dividing circuit comprises a voltage dividing resistor R1 and a voltage dividing resistor R2 connected in series.

[0015] As preferred, a sampling port is connected between the voltage dividing resistor R1 and the voltage dividing resistor R2.

[0016] Based on the above, the utility model can preferably sample the circuit.

[0017] The power supply switching circuit based on priority according to the utility model comprises a plurality of power supply circuit modules connected in sequence, and the power supply circuit module adopts any one of the power supply circuit modules.

[0018] Based on the above, the utility model can preferably select the power supply with the highest priority in the power supply being powered according to the priority of the power supply corresponding to each power supply circuit module, such as the priority determined by the voltage, current size and stability of the power supply, to meet the power supply demand, and when the number or type of power supply is large, the utility model can complete the switching between multiple power supplies without a comparator, and the circuit is simple to realize.

[0019] As preferred, the encoding circuit is included for connecting with the plurality of power supply circuit modules simultaneously. Thus, the power supply corresponding to the plurality of power supply circuit modules can be encoded preferably.

[0020] As preferred, the encoding circuit includes an encoding chip U1.

[0021] As preferred, the encoding chip U1 has an input pin and an output pin for accessing the controller. Thus, the encoding of the power supply in the power supply state can be output to the controller preferably.

[0022] According to the power supply switching method based on priority of the utility model, it includes using the power supply switching circuit of any of the above to switch power supply. Thus, the power supply of the power supply to the load can be realized preferably, in addition, the power supply circuit is modularized, and the topology is carried out according to the power supply priority order, and only the cascade port of each module needs to be connected during the topology. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is the circuit diagram of the power supply circuit module of embodiment 1;

[0024] Figure 2 It is the circuit block diagram of the power supply switching circuit based on priority of embodiment 2;

[0025] Figure 3 It is the circuit diagram of another power supply circuit module of embodiment 2;

[0026] Figure 4 It is the circuit diagram of the encoding circuit of embodiment 2. DETAILED DESCRIPTION

[0027] In order to further understand the content of the embodiment, the embodiment is described in detail in combination with the embodiment. It should be understood that the embodiment is only explained and not limited.

[0028] Embodiment 1

[0029] As shown in Figure 1 The embodiment gives a circuit diagram of a power supply circuit module, which includes:

[0030] A relay having a control coil, a normally closed contact and a normally open contact;

[0031] A coil control branch connected in series with the control coil, for being connected in series with the power supply, and including a first cascade port connected in series between the power supply and the control coil;

[0032] A power supply branch connected in series with the normally open contact, the power supply branch being connected in series between the power supply and the load; and

[0033] The second cascade port is connected in series with the normally closed contact and is used to connect to the first cascade port of another power supply circuit module.

[0034] Based on the above, this embodiment can better realize the power supply to the load. In addition, it can also better realize the topology according to the power priority order through the modular power supply circuit. Only the cascade ports of each module need to be connected during topology. The modular design can be compatible with the priorities on both the upper and lower sides. The priority can be automatically selected according to the circuit topology without the need to detect the quality of each power supply separately.

[0035] In this embodiment, a time-delay branch is included, which is connected in parallel with the control coil. Therefore, it is possible to achieve a better delay in opening the normally open contact of the relay when it is closed.

[0036] In this embodiment, the delay branch includes an energy storage capacitor C1, the rated capacity of which 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 operating time of the normally closed or 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 effectively protect the circuit.

[0037] In this embodiment, 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.

[0038] 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 form 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.

[0039] In this embodiment, a sampling port is connected between the voltage divider resistors R1 and R2.

[0040] Based on the above, this embodiment can better achieve circuit sampling.

[0041] Example 2

[0042] like Figure 2 As shown in the figure, this embodiment provides a priority-based power supply switching circuit, including eight power supply circuit modules and an encoding circuit. The workflow of this embodiment is as follows: the front-end circuit inputs multiple power supplies, and after entering the priority competition power supply loop, the priority competition power supply loop determines the priority power supply loop and outputs power to the load. At the same time, the competition result is output to the encoding circuit for encoding. The encoding circuit encodes and outputs the result to the controller for control logic processing or protection of the subsequent load circuit.

[0043] In combination Figure 1 , Figure 3 and Figure 4 As shown in the following embodiments of two power supply circuit modules and a code chip U1 as an example of the working principle of the priority-based power supply switching circuit, the sampling port of the two power supply circuit modules is connected to the pin 15 and pin 14 of the code chip U1 in the order of cascade, and if more paths are required for competition power supply, only the single loop needs to be expanded.

[0044] In this embodiment, the two power supply circuit modules are connected in the form of cascade port H-OUT1 and cascade port H-IN2. Assuming that the starting power supply is the second power supply PWR2 and the first power supply PWR1 is not connected, at this time, the relay K1 is not actuated, the normally closed contact of the relay K1 is closed (i.e. the pin 6 and pin 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 resistor R3 and the voltage dividing resistor R4 to pull up PWR-WK2. After the relay K2 is actuated, the pin 3 and pin 4 contacts 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 is opened (i.e. the pin 6 and pin 7 of the relay K2 are disconnected), and the lower circuit power supply is closed.

[0045] When the first power supply PWR1 is connected during the second power supply PWR2 power supply, the coil of the relay K1 is powered, which will drive the normally closed contact of the relay K1 to open (i.e. the pin 6 and pin 7 of the relay K1 are disconnected), and the pin 3 and pin 6 contacts of the relay K1 are respectively moved from the pin 2 and pin 7 to the pin 4 and pin 5. Among them, there is a state, that is, 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 be supplied to the load through the pin 4 contact of the relay K1 through PWR-OUT, and the driving voltage of the relay K2 has been shut down by the pin 7 contact of the relay K1. If the relay K2 is actuated immediately at this time, the power supply of the second power supply PWR2 to the load through the pin 4 contact of the relay K2 will also be immediately cut off, and the power supply of the load circuit will be temporarily interrupted.

[0046] Therefore, in some places where the power supply requirement is higher, that is, in places where the non-inductive (i.e. no power interruption) switching power supply requirement of multiple power supplies is required, a delay circuit can be provided at the control coil of the relay in this embodiment. After the control circuit of the relay K2 is cut off, it can still maintain at least the duration of the movement of the pin 3 of the relay K2 from the pin 2 to the pin 4. In this embodiment, a storage capacitor is added to the relay to realize the delay of the relay K2, which is as follows:

[0047] The multi-level power supply is usually powered by a positive power supply. Considering that the noise fluctuation caused by the change of the load of the power supply ground plane may cause the misoperation of the non-polarity coil, the embodiment adopts a polarity relay, and an electrolytic capacitor is used to store energy for the relay. Since the relay is an inductive element, when the driving power supply is cut off, a transient reverse driving voltage will be generated at both ends of the relay coil, which will cause the reverse breakdown of the electrolytic capacitor. Therefore, a freewheeling diode is added to absorb the reverse electromotive force and protect the electrolytic capacitor.

[0048] Suppose the parameters of the selected relay are as follows: the driving voltage is Ue (V), the pull-in voltage is UMAX (V), the release voltage is UMIN (V), the rated power consumption is P (W), and the action and release time is t (s). To ensure inductive switching of the power supply, the power supply circuit with high priority is turned on and then the power supply circuit with low priority is cut off after a time t. On the relay driving branch, the voltage at both ends of the relay corresponding to the power supply with low priority should be greater than UMIN within time t. Due to the existence of the freewheeling diode, a current spike caused by the reverse electromotive force will occur at the moment when the driving voltage is cut off, causing loss of the relay core energy and core loss caused by 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 time t.

[0049] Considering the manufacturing deviation of the relay, the error limit value of the pull-in time of K1 and the release time of K2 is 0.3t, so 0.5t of time redundancy is added. Therefore, the capacitor energy storage value within the relay switching time should be: W = 1.5 * P * t; the capacitance value should be: C = 1.5 * P * t / Ue; and the capacitance voltage should be greater than 1.4Ue.

[0050] Based on the above, the embodiment can selectively switch and inductively switch to the power supply with the highest priority according to the priority of the power supply, such as the voltage, current size, and stability of the power supply.

[0051] In the embodiment, an encoding circuit is included, which is used to be connected with multiple power supply circuit modules. Therefore, the power supply corresponding to the multiple power supply circuit modules can be encoded.

[0052] In combination with Figure 4 In the embodiment, the encoding circuit includes an encoding chip U1, and the model of the encoding chip U1 can be 74LS138, 74LS139, CD4514B, or CD4017B.

[0053] ​In the embodiment, the coding chip U1 has an output pin for the access controller and an input pin for the access sampling port. Thus, the coding output of the power supply in the power supply state can be preferably realized to the controller. Thus, the monitoring of the power supply can be preferably realized.

[0054] Embodiment 3

[0055] The embodiment provides a priority-based power supply switching method, which adopts the power supply switching circuit in any one of the above-mentioned embodiments 2 to switch the power supply. Thus, the power supply switching can be preferably realized when multiple power supplies supply power simultaneously, and the power supply switching can be inductively realized to the power supply with the highest priority, and in addition, the power supply circuit can be modularized, and the topology can be performed according to the priority order of the power supply, and only the cascade ports of the modules need to be connected during the topology.

[0056] It is easy to understand that the person skilled in the art can combine, split, recombine and the like on the basis of one or more embodiments provided in the application to obtain other embodiments, and these embodiments do not exceed the protection scope of the application.

[0057] The above describes the utility model and its embodiments in a schematic manner, and the description is not restrictive, and the embodiments shown are only part of the embodiments of the utility model, and the actual structure is not limited thereto. Therefore, if the ordinary skilled in the art is inspired, without departing from the creative spirit of the utility model, without creative design, similar structure and embodiments of the technical scheme should belong to the protection scope of the utility model.

Claims

1. A power supply circuit module, characterized by, Comprising: 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 for series connection to a power supply, and comprising 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 and a load; a second cascade port connected in series with the normally closed contact, the second cascade port being for connection to a first cascade port of another power supply circuit module.

2. The power supply circuit module according to claim 1, characterized in that, a delay branch for connection in parallel with the control coil.

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

4. The power supply circuit module according to claim 3, characterized in that, a freewheeling diode D1 for connection in parallel with an energy storage capacitor C1.

5. The power supply circuit module according to claim 1, characterized by a voltage dividing circuit provided between the power supply and a ground terminal, the voltage dividing circuit comprising 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 connected between the voltage dividing resistor R1 and the voltage dividing resistor R2.

7. Priority-based power supply switching circuit, characterized in that a plurality of power supply circuit modules connected in cascade, the power supply circuit modules being any one of the power supply circuit modules of claims 1-6.

8. The power supply switching circuit of claim 7, wherein an encoding circuit for connection to the plurality of power supply circuit modules simultaneously.

9. The power supply switching circuit of claim 8, wherein: the encoding circuit comprises an encoding chip U1.

10. The power supply switching circuit of claim 9, wherein: the encoding chip U1 has an input pin and an output pin for connection to a controller.

Images