External DC dual power supply switching battery
By introducing a step-down chip and control circuit into the solar street light, the synchronous switching of the mains and battery voltages is achieved, solving the power interruption problem when the solar street light switches to DC power supply and ensuring the stability and continuity of lighting.
Patent Information
- Application Number
- CN202422565095.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-23
- Publication Date
- 2025-09-19
- Estimated Expiration
- 2034-10-23
AI Technical Summary
When the battery power supply of existing solar street lights is insufficient, there will be a short power interruption problem when switching to DC power supply, and there is a lack of active switching capability.
A step-down chip and control circuit are used to control the relay through the comparison circuit and switching circuit to ensure the synchronous switching of the mains power and battery voltage. The step-down chip is used to step down the mains power to the normal operating voltage of the street lamp, and the comparator and transistor are used to control the action of the relay to achieve stable power switching.
It achieves smooth switching between mains power and battery, avoids short power interruption of solar street lights during switching, and ensures the stability and continuity of lighting.
Smart Images
Figure CN223363891U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of direct current (DC) power supply technology, and in particular to an external DC dual power supply switching battery. Background Art
[0002] Solar street lights are a type of lighting equipment that uses solar energy as energy, converting solar energy into electrical energy, providing a clean, renewable energy source for nighttime lighting and reducing the consumption of fossil fuels.
[0003] Typically, a solar street light consists of a solar panel, battery, controller, relay, and lighting components. The solar panel receives sunlight and converts it into electricity through the photovoltaic effect. This electricity is then stored in the battery and used to power the lighting components at night when sunlight is insufficient. Solar street lights typically require an external DC power supply, or mains electricity. Mains electricity serves as a secondary power source. If the battery charge is low, the street light controller switches to mains power to ensure stable lighting. Alternatively, when the battery charge is sufficient, the light automatically switches back to battery power.
[0004] Regarding the above-mentioned related technologies, the access switching of batteries and DC power supplies is achieved by relay switching contacts. Most solar street lights themselves do not have the initiative to change batteries. Therefore, when the battery power supply is insufficient and the solar street light switches to the DC power supply, there will be a short period of time when the solar street light is without power, that is, the solar street light will not light up for a short period of time. Summary of the Invention
[0005] In order to ensure that the action of the relay contacts does not affect the power supply of the solar street lamp during power supply switching, the present application provides an external DC dual power supply switching battery.
[0006] The present application provides an external DC dual power supply switching battery using the following technical solution:
[0007] An external DC dual power supply switching battery includes a sampling circuit and a control circuit, wherein the sampling circuit and the control circuit are connected to a relay, a battery, an external DC power supply, and a controller;
[0008] The sampling circuit includes a step-down chip, the step-down chip is connected to a battery and an external DC power supply, and the output end of the step-down chip is connected to the control circuit;
[0009] The control circuit includes a comparison circuit and a switching circuit. The comparison circuit is connected to the output end of the step-down chip, and the switching circuit is connected to a battery and an external DC power supply.
[0010] By adopting the above technical solution, a step-down chip is added to the existing solution. In actual application, the step-down chip is integrated into a single-chip microcomputer or a controller. The step-down chip is used to step down the mains voltage to the normal operating voltage of the street lamp lighting component.
[0011] After the step-down, the step-down chip obtains an output voltage and a reference voltage used as a comparison benchmark, which are jointly transmitted to the comparison circuit of the subsequent control circuit; on the basis of the AC power supply, the reference voltage is compared with the output voltage of the battery. When the reference voltage is greater than the output voltage of the battery, the AC power is used for power supply; when the AC reference voltage is less than the output voltage of the battery, the battery is used for power supply.
[0012] Optionally, the enable terminal of the step-down chip is connected to an external DC power supply.
[0013] By adopting the above technical solution, the operation stability of the microcontroller or the buck chip is maintained, and it operates synchronously with the mains. When the mains is connected, the mains directly supplies the buck chip to ensure the mains power supply of subsequent street lighting components.
[0014] Optionally, the comparison circuit includes a comparator, the positive and negative poles of the comparator are connected; the switching circuit includes a first transistor, the output end of the comparator is connected to the base of the first transistor, the emitter of the first transistor is connected to the relay, and the collector of the first transistor is connected to the output end of the step-down chip.
[0015] By adopting the above technical solution, the access end of the comparator is respectively connected to the output end of the battery and the output voltage of the AC power after the voltage is reduced, and a comparison is made; it should be noted that in actual applications, the output voltage of the battery is generally connected to the positive electrode of the comparator; the output voltage of the above comparator is connected to the base of the first transistor, which is used to control the conduction of the first transistor. When the output voltage of the battery is greater than the preset difference of the reduced voltage of the AC power, the first transistor is turned on, and the output voltage of the battery is transmitted to the vicinity of the relay to control the operation of the relay.
[0016] Optionally, the control circuit further includes a second transistor, the base of which is connected to the emitter of the first transistor and the signal output end of the buck chip; the emitter of the second transistor is grounded, and the collector of the second transistor is connected to a relay.
[0017] By adopting the above technical solution, the base of the second transistor is connected to the emitter of the first transistor. When the comparison voltage conducts the first transistor, the mains voltage is transmitted to the second transistor, and the base of the second transistor is turned on, thereby controlling the operation of the relay.
[0018] In this solution, the base of the second transistor is also connected to the signal output terminal of the buck chip. Therefore, the conduction condition of the second transistor is the superposition of the mains step-down voltage and the voltage of the electrical signal of the buck chip. When the buck chip, that is, the microcontroller, does not send a conduction electrical signal, the second transistor cannot be turned on, thereby enhancing the controllable performance of the relay contact switching process.
[0019] Optionally, one end of the coil of the relay is connected to the output end of the buck chip, and the other end of the relay coil is connected to the collector of the second transistor.
[0020] By adopting the above technical solution, the collector of the second transistor is connected to the relay coil, the emitter of the second transistor is grounded, and the output end of the step-down chip is connected to the relay coil so that the relay is in the on state when the second transistor is turned on. The relay operates and the normally closed contact is replaced by another contact; if the second transistor is not turned on, the relay does not operate and is in the normally closed state.
[0021] Optionally, a first diode is provided between the coil connection nodes of the relay, and the anode of the first diode is grounded and the cathode is connected to the output end of the buck chip.
[0022] By adopting the above technical solution, the anode of the first diode is grounded. More precisely, the anode of the first diode is connected to the collector of the second transistor, and the emitter of the second transistor is grounded. The output end of the step-down chip is directly connected to the relay, which forms a loop with the coil while preventing the DC current of the step-down chip from directly flowing into the collector of the second transistor.
[0023] Optionally, a voltage divider circuit is provided between the comparator and the positive electrode of the battery.
[0024] By adopting the above technical solution, the filter circuit stabilizes the voltage to protect the subsequent comparator. When the comparator is running, the gate cannot be at zero potential. Before the battery output end is turned on, the current flows through the voltage divider circuit. When the voltage divider circuit is in operation, the gate of the comparator is distributed to an operating voltage to prevent its gate potential from being suspended.
[0025] Optionally, a second diode is provided between the second triode and the first triode, the anode of the second diode is connected to the first triode, and the cathode of the second diode is connected to the second triode.
[0026] By adopting the above technical solution, when the second transistor is not conducting and the first transistor is conducting, that is, when the microcontroller does not send a conduction signal, the base non-conduction of the second transistor can be avoided from hindering the emitter current of the first transistor from flowing back along the circuit.
[0027] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The accompanying drawings are only used to illustrate the preferred embodiments and are not to be considered as limiting the present application. In addition, the same reference symbols are used to represent the same components throughout the drawings. In the drawings:
[0029] Figure 1 is a circuit diagram of a sampling circuit in an embodiment of the present application.
[0030] Figure 2 is a circuit diagram of a control circuit in an embodiment of the present application.
[0031] Explanation of the accompanying symbols: 1. sampling circuit; 11. buck chip; 12. voltage regulator diode; 2. control circuit; 21. voltage divider circuit; 22. relay; 23. first diode; 24. second diode; 25. first transistor; 26. second transistor; 27. comparator. DETAILED DESCRIPTION
[0032] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.
[0033] Reference Figure 1 and Figure 2 An external DC dual power supply switching battery includes a sampling circuit 1 and a control circuit 2.
[0034] Reference Figure 1 and Figure 2 Sampling circuit 1 is connected to the AC current output terminal, i.e., the DC positive terminal. Simultaneously, sampling circuit 1 is connected to the AC current input terminal and the battery current input terminal, i.e., the DC negative terminal and the battery current negative terminal. Control circuit 2 is connected to the DC current positive terminal and the battery current positive terminal. For ease of notation, the DC positive and negative terminals are represented as DC+ and DC-, and the battery current positive and negative terminals are represented as BATTERY+ and BATTERY-. Sampling circuit 1 is connected to control circuit 2, so the AC current flows into sampling circuit 1, control circuit 2, and ultimately returns to control circuit 2.
[0035] Reference Figure 1 and Figure 2The sampling circuit 1 includes a step-down chip 11, which is integrated into the street light controller. The input pin and enable pin of the step-down chip 11 are connected to the mains, and the output pin is connected to the control circuit 2. When the external DC power supply is turned on, the step-down chip 11 operates synchronously to reduce the 220V mains to a preset voltage. In this embodiment, the output voltage of the step-down chip 11, i.e., the step-down voltage, is represented as VC1, which is input to the control circuit 2. The electrical signal output pin of the step-down chip 11 outputs a comparison voltage, which is transmitted to the subsequent control circuit 2 for comparison with the output voltage of the battery to determine whether to switch the current supply. In this embodiment, the FB feedback pin is used as the comparison voltage output pin. When the step-down chip 11 has current output, that is, when the sampling circuit 1 is connected to the external mains, the FB feedback pin synchronously outputs the comparison voltage REF.
[0036] refer to Figure 2 Control circuit 2 connects the streetlight's power supply circuit, an external DC power supply, and a battery. It inputs the mains electricity or the battery's stored energy into the streetlight's power supply circuit input. In this embodiment, COMMON+ represents the streetlight's power supply circuit input. Control circuit 2 includes a relay 22, located between the COMMON+, BATTERY+, and DC+ interfaces. The COMMON+ interface is a moving contact, while the BATTERY+ and DC+ interfaces are static contacts. The BATTERY+ interface is a normally closed contact, indicating that the streetlight's primary power supply is battery power.
[0037] Reference Figure 1 and Figure 2 The control circuit 2 includes a comparator 27. In practical applications, a MOS tube is generally used. Since the battery is the main power supply method in this embodiment, the positive electrode of the battery is connected to the positive electrode of the comparator 27, and the comparison voltage REF is connected to the negative electrode of the comparator 27. Taking into account that in actual situations, the battery corresponds to the street lamp one-to-one and is set inside the main pole of the street lamp, the output voltage of the battery is adapted to the rated voltage of the street lamp under this specification and does not need to be reduced. Therefore, the comparison voltage REF of the above-mentioned buck chip 11 should be divided. Therefore, the FB interface of the buck chip 11 inside the sampling circuit 1 is connected to a fixed-value resistor. The voltage of REF is maintained at a preset level by the preset fixed-value resistor value. At the same time, a voltage regulator diode 12 is set to stabilize the output voltage value of REF to ensure the accuracy of the comparator 27.
[0038] Reference Figure 2 In this embodiment, a voltage divider circuit 21 is provided between the output end of the battery and the comparator 27. The voltage divider circuit 21 is composed of a filter capacitor and a voltage divider resistor in parallel. Since the comparator 27 uses a MOS tube, the gate cannot be left floating when current passes through it. Therefore, a voltage divider resistor is used to fix the gate potential to protect the MOS tube.
[0039] Reference Figure 1 and Figure 2 Control circuit 2 includes a first transistor 25. The base of first transistor 25 is connected to the output of comparator 27, and the collector of first transistor 25 is connected to the output voltage VC1 of step-down chip 11. When the voltage at the input terminal of comparator 27, BATTERY+, is greater than the voltage at REF, comparator 27 outputs a voltage, turning on the base of first transistor 25. The voltage VC1 flows through the emitter to the subsequent circuit modules. In practical applications, the VC1 current should be diverted to the base of first transistor 25, connected to a fixed resistor, and the conduction condition of first transistor 25 should be adjusted through VC1.
[0040] Reference Figure 2 Control circuit 2 includes a second transistor 26. The base of second transistor 26 is connected to the aforementioned VC1 voltage and the streetlight controller. The controller transmits a control signal. In this embodiment, RELAY represents the control signal transmitted by the controller. At the base of second transistor 26, the RELAY voltage is superimposed on the VC1 voltage. An additional fixed resistor should be provided at second transistor 26 to further lower the VC1 voltage, so that the VC1 voltage is less than the base conduction voltage of second transistor 26. Therefore, VC1 alone cannot turn on second transistor 26; it requires the simultaneous receipt of the RELAY signal from the controller to turn on second transistor 26.
[0041] Reference Figure 2 One end of the coil of the relay 22 is connected to VC1, and the other end is connected to the collector of the second transistor 26. The emitter of the second transistor 26 is grounded. Therefore, when the second transistor 26 is turned on, the relay 22 operates. A first diode 23 is connected between the two nodes of the coil of the relay 22. The cathode of the first diode 23 is connected to VC1, which is used for unidirectional conduction of the coil circuit of the relay 22. Therefore, when the second transistor 26 is not turned on, the relay 22 is disconnected and remains closed.
[0042] The voltage value of the REF comparison voltage is a preset value. In actual application, technicians should determine it according to the local power supply conditions. The higher the REF voltage, the smaller the comparison difference between the battery output voltage and the REF voltage, and the easier it is for the street lamp to switch to mains power supply.
[0043] Reference Figure 2 A second diode 24 is provided between the emitter of the first transistor 25 and the base of the second transistor 26. The anode of the second diode 24 is connected to the emitter of the first transistor 25, and the cathode of the second diode 24 is connected to the base of the first transistor 25 to prevent the current of the emitter of the first transistor 25 from flowing back when the second transistor 26 is not conducting.
[0044] The implementation principle of an external DC dual power supply switching battery in the embodiment of the present application is as follows: the comparator 27 uses the positive input terminal as the reference terminal.
[0045] When no external DC power supply is connected, the battery is used for power supply. When the external DC power supply, that is, the mains power is connected, the step-down chip 11 outputs a step-down voltage. The comparator 27 compares the mains power step-down voltage with the battery output voltage. When the battery voltage is lower than the mains power step-down voltage, the output end of the comparator 27 outputs a high level, which is superimposed on VC1 and input to the base of the first transistor 25. When the output voltage difference of the battery is large, the base is turned on, and VC1 is transmitted to the base of the second transistor 26. Based on the control electrical signal sent by the controller, the second transistor 26 is turned on, the relay 22 operates, and the switching contact is powered by the external DC power supply.
[0046] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.
Claims
1. An external DC dual power supply switching battery, characterized by: It comprises a sampling circuit (1) and a control circuit (2), wherein the sampling circuit (1) and the control circuit (2) are connected to a relay (22), a battery, an external DC power supply, and a controller; The sampling circuit (1) comprises a step-down chip (11), the step-down chip (11) is connected to a battery and an external DC power supply, and the output end of the step-down chip (11) is connected to the control circuit (2); The control circuit (2) comprises a comparison circuit and a switching circuit, wherein the comparison circuit is connected to the output end of the step-down chip (11), and the switching circuit is connected to a battery and an external DC power supply.
2. The external DC dual power supply switching battery according to claim 1, characterized in that: The enable terminal of the step-down chip (11) is connected to an external DC power supply.
3. The external DC dual power supply switching battery according to claim 1, characterized in that: The comparison circuit includes a comparator (27), the positive and negative electrodes of the comparator (27) are connected; the switching circuit includes a first transistor (25), the output end of the comparator (27) is connected to the base of the first transistor (25), and the emitter of the first transistor (25) is connected to the relay (22).
4. The external DC dual power supply switching battery according to claim 3, characterized in that: The control circuit (2) further comprises a second triode (26), the base of the second triode (26) being connected to the emitter of the first triode (25) and the signal output end of the step-down chip (11); the emitter of the second triode (26) being grounded, and the collector of the second triode (26) being connected to the relay (22).
5. The external DC dual power supply switching battery according to claim 4, characterized in that: One end of the coil of the relay (22) is connected to the output end of the step-down chip (11), and the other end of the coil of the relay (22) is connected to the collector of the second transistor (26).
6. The external DC dual power supply switching battery according to claim 5, characterized in that: A first diode (23) is provided between the coil connection nodes of the relay (22), wherein the anode of the first diode (23) is grounded and the cathode is connected to the output end of the step-down chip (11).
7. The external DC dual power supply switching battery according to claim 3, characterized in that: A voltage dividing circuit (21) is provided between the comparator (27) and the positive electrode of the battery.
8. The external DC dual power supply switching battery according to claim 4, characterized in that: A second diode (24) is provided between the second triode (26) and the first triode (25), the anode of the second diode (24) is connected to the first triode (25), and the cathode of the second diode (24) is connected to the second triode (26).