Power taking circuit of LED lamp

Abstract

According to the technical scheme provided by the invention, an LED lamp power supply directly takes electricity from a battery end without passing through a diode, voltage drop is reduced, then a switch element with relatively small internal resistance is used as a circuit switch of an LED, the switch element is controlled to be switched on when the LED lamp needs to be turned on, and when electricity is taken through the circuit structure provided by the invention, the LED lamp can be switched on, so that the LED lamp can be powered on. Even if the battery is insufficient in power and the voltage of the battery is relatively low, the voltage drop of the traditional power taking circuit is avoided, the disadvantage that the LED lamp cannot be lightened when the power of the battery is relatively low is avoided, and the service time limit of the LED can be effectively prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of smart home devices, and in particular to a power supply circuit for an LED lamp. Background Art

[0002] Currently, many wireless products on the market often use multiple batteries for power supply. Diodes need to be added to the circuit to isolate them and then power the system. Generally, there will be LED indicators on the products to interact with the user. The general design method in the industry is to directly draw power from the cathode end of the diode. The circuit structure is as follows: Figure 1 As shown, this ensures that the chip power supply voltage is consistent with the LED power supply voltage, and there will be no power loss when the LED is not lit, thus meeting the low power consumption requirement. However, in actual applications, LEDs that adopt this power supply structure are prone to light failure as the product continues to be used, affecting the user experience. Utility Model Content

[0003] The present application discloses a power supply circuit for an LED lamp, which is used to solve the technical problem that the existing power supply circuit structure for an LED lamp is prone to light emission failure.

[0004] In order to solve the above technical problems, the first aspect of the present application provides an LED lamp power supply circuit, comprising: an LED element, a low internal resistance switch element and an MCU module, wherein the MCU module is connected to the control end of the low internal resistance switch element to control the on and off of the low internal resistance switch element;

[0005] The LED element is connected in series with the low internal resistance switch element to form a light-emitting circuit of a serial structure;

[0006] One end of the light-emitting circuit is a ground terminal, and the other end is a power supply terminal for electrical connection with a multi-battery power supply module, wherein the access position of the power supply terminal is located between the positive electrode of the battery and the anode of the diode of one group of battery circuits in the multi-battery power supply module.

[0007] Optionally, the series connection sequence of the light-emitting circuit is: the power supply end, the LED element, the low internal resistance switch element and the ground end.

[0008] Optionally, the series connection sequence of the light-emitting circuit is: the power supply end, the low internal resistance switch element, the LED element and the ground end.

[0009] Optionally, the light-emitting circuit further includes: a first current-limiting resistor;

[0010] The first current limiting resistor is connected in series with the anode of the LED element.

[0011] Optionally, it further includes: a pull-down resistor and a second current-limiting resistor, wherein the pull-down resistor and the second current-limiting resistor are arranged between the MCU module and the low internal resistance switch element.

[0012] Optionally, the low internal resistance switch element includes: a MOS tube or a triode.

[0013] Optionally, the lighting circuit further includes: a switch protection element for protecting the low internal resistance switch element.

[0014] Optionally, the switch protection element includes: an ESD tube.

[0015] It can be seen from the above technical solutions that this application has the following advantages:

[0016] The technical solution provided by the present application draws power for the LED lamp directly from the battery end without passing through a diode to reduce the voltage drop, and then uses a switching element with a small internal resistance as the circuit switch of the LED. When the LED lamp needs to be turned on, the switching element is controlled to be turned on. When power is drawn through the circuit structure provided by the present application, even when the battery is low and the battery voltage is low, there will be no voltage drop like the power-drawing circuit of the traditional battery using a diode, thus avoiding the disadvantage that the LED lamp cannot be lit when the battery power is low, and can effectively extend the service life limit of the LED. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 It is a structural schematic diagram of an existing LED lamp power supply circuit;

[0019] Figure 2 This is a schematic diagram of the structure of a power supply circuit for an LED lamp provided in an embodiment of the present application;

[0020] The reference numerals include:

[0021] R1, R2: first current limiting resistors, D3: LED component, D5, D6: ESD tubes, Q1, Q2: NMOS tubes, R4, R7: pull-down resistors, R5, R6: second current limiting resistors. DETAILED DESCRIPTION

[0022] Through in-depth research on the defects in the prior art, it was found that the reason for the above phenomenon is that as the continuous use time of the product increases, the battery power of the product decreases. As the battery voltage decreases, the voltage obtained by the LED lamp after the diode voltage reduction is lower. For example, assuming that the LED conduction voltage is 2.2v, but the diode voltage drop is at least 0.3v, the battery voltage needs to be above 2.5v for the LED indicator to light up. Once the battery voltage is lower than 2.5v, the LED will no longer be able to light up, resulting in the product still working normally, but the LED indicator is no longer on, and other lighting failures, seriously affecting the user experience.

[0023] In view of this, and in response to the above-discovered technical problems, an embodiment of the present application discloses an LED lamp power supply circuit for solving the technical problem that the existing LED lamp power supply circuit structure is prone to light emission failure.

[0024] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0025] Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0026] See also Figure 2 , an LED lamp power supply circuit provided in an embodiment of the present application comprises: an LED element, a low internal resistance switch element and an MCU module, wherein the MCU module is connected to a control end of the low internal resistance switch element to control the on and off of the low internal resistance switch element;

[0027] The LED element is connected in series with the low internal resistance switch element to form a light-emitting circuit of a serial structure;

[0028] One end of the light-emitting circuit is a ground terminal, and the other end is a power supply terminal for electrical connection with a multi-battery power supply module, wherein the access position of the power supply terminal is located between the positive electrode of the battery and the anode of the diode of one group of battery circuits in the multi-battery power supply module.

[0029] It should be noted that each battery circuit in the multi-battery power module includes a battery and a diode. Since the multi-battery power module shown in the figure includes two parallel battery circuit structures, more battery circuits can be set in some embodiments, in which multiple batteries can be isolated by diodes and are in a similar parallel relationship in space. Therefore, the corresponding light-emitting circuits are also two groups. Since the composition of the two groups of light-emitting circuits is basically the same, this embodiment only takes one group as an example for illustration.

[0030] First, the LED element is connected in series with a low internal resistance switch element to form a serial structure light-emitting circuit. One end of the light-emitting circuit is grounded, and the other end is connected between the positive electrode of the battery in one group of battery circuits and the anode of the diode, so that the power supply of the LED lamp is directly powered by the battery end without passing through the diode to reduce the voltage drop. Then, a switch element with a relatively small internal resistance is used as the circuit switch of the LED, such as an NMOS tube or an NPN transistor electronic switch or other analog switch. Taking the NMOS tube as an example, the available models are AH150N03: internal resistance 4mΩ, AH60N04: internal resistance 5mΩ or AH85N03: internal resistance 8mΩ, etc. When the LED lamp needs to be turned on, the MOS tube and other switches are turned on. Since the internal resistance of the MOS tube is very small and the LED current is at the mA level, the voltage VDS between the drain and the source is ≈ 0V. In this way, the above-mentioned battery voltage is low and the duration of the LED being turned on can be extended at a very low cost.

[0031] Furthermore, the LED lamp power supply circuit mentioned in this embodiment also includes: a first current limiting resistor;

[0032] The first current limiting resistor is connected in series with the anode of the LED element to protect the LED element.

[0033] Optionally, it further includes: a pull-down resistor and a second current-limiting resistor, wherein the pull-down resistor and the second current-limiting resistor are arranged between the MCU module and the low internal resistance switch element.

[0034] Optionally, the low internal resistance switch element includes: a MOS tube or a triode.

[0035] Optionally, the light-emitting circuit further includes: a switch protection element for protecting the low internal resistance switch element, and the switch protection element can be an ESD tube.

[0036] Then the GPIO port of the MCU is connected to a pull-down resistor, and then connected to the gate of the switch tube NMOS through a current limiting resistor to control the on and off of the MOS tube. At the same time, in order to protect the NMOS tube from being broken down by electrostatic ESD, this embodiment also adds an ESD tube to the drain of the MOS tube.

[0037] The above is a detailed introduction to an LED lamp power supply circuit provided by the present application. For a person skilled in the art, according to the idea of ​​the embodiments of the present application, there may be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A LED lamp power supply circuit, characterized in that: include: LED elements, low internal resistance switch elements and MCU modules, wherein the MCU module is connected to the control end of the low internal resistance switch element and is used to control the on and off of the low internal resistance switch element; The LED element is connected in series with the low internal resistance switch element to form a light-emitting circuit of a serial structure; One end of the light-emitting circuit is a ground terminal, and the other end is a power supply terminal for electrical connection with a multi-battery power supply module, wherein the access position of the power supply terminal is located between the positive electrode of the battery and the anode of the diode of one group of battery circuits in the multi-battery power supply module.

2. The LED lamp power supply circuit according to claim 1, characterized in that: The series connection sequence of the light-emitting circuit is: the power supply end, the LED element, the low internal resistance switch element and the ground end.

3. The LED lamp power supply circuit according to claim 1, characterized in that: The series connection sequence of the light-emitting circuit is: the power supply end, the low internal resistance switch element, the LED element and the ground end.

4. The LED lamp power supply circuit according to claim 1, characterized in that: The light-emitting circuit further includes: a first current-limiting resistor; The first current limiting resistor is connected in series with the anode of the LED element.

5. The LED lamp power supply circuit according to claim 1, characterized in that: Also includes: A pull-down resistor and a second current-limiting resistor, wherein the pull-down resistor and the second current-limiting resistor are arranged between the MCU module and the low internal resistance switch element.

6. The LED lamp power supply circuit according to claim 1, characterized in that: The low internal resistance switch element includes: a MOS tube or a triode.

7. The LED lamp power supply circuit according to claim 1, characterized in that: The light-emitting circuit further includes: a switch protection element, which is used to protect the low internal resistance switch element.

8. The LED lamp power supply circuit according to claim 7, characterized in that: The switch protection element includes: an ESD tube.

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