A failure detection circuit and detection method for LED lights

Abstract

The invention discloses a failure detection circuit for an LED lamp. The detection circuit includes an LED lamp, a negative feedback module, a reference voltage module and a failure detection module. The reference voltage module controls the current flowing through the LED lamp through the negative feedback module To adjust the brightness of the LED lamp, the input terminal of the failure detection module is connected to the LED lamp to detect the failure state of the LED lamp, and the output terminal of the failure detection module is connected to the negative feedback module through the single chip microcomputer; the failure detection module includes a parallel connection The sixth diode D6 and the second diode D2, the sixth diode D6 is set close to the LED lamp, and the second diode D2 is set at ambient temperature; the invention also discloses LED lamp failure detection method. The present invention can detect the failure state of the LED lamp through the failure detection module, and take corresponding measures according to the failure state to prevent the damage of the LED lamp; at the same time, the present invention uses an external reference voltage module and a negative feedback module to realize the LED lamp Dynamic adjustment of current.

Description

technical field [0001] The invention belongs to the technical field of LED lamp failure detection, and in particular relates to a failure detection circuit and a failure detection method for LED lamps. Background technique [0002] LED light, or light-emitting diode, is a solid-state semiconductor device that can convert electrical energy into visible light. It can directly convert electricity into light, so it has a wider application market. [0003] However, LED lights will fail with the use of time or changes in the surrounding environment, for example: due to excessive current, the PN junction temperature is too high, and the PN junction temperature is too high due to the excessive ambient temperature of the working condition, resulting in positive feedback of the LED current and eventually failure. . [0004] Existing LED lamp circuit failure detection generally uses NTC sampling circuit for real-time detection, its disadvantages are high cost of NTC hardware, too many...

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Problems solved by technology

[0003] The LED lamp will fail with the use time or the change of the surrounding environment. For example, the PN junction temperature is too high and the temperature is too high due to the current excess; the PN junction temperature is too high due to the excessive ambient temperature of the working condition, resulting in positive feedback of the LED current and finally failure.

[0004] Existing LED lamp circuit failure detection generally uses NTC sampling circuit for real-time detection, its disadvantages are high cost of NTC hardware, too many MCU detection ports, and unclear theoretical support; and the existing LED lamp circuits are generally based on switching power supply LED constant current circuit, which is used in high-power occasions, has disadvantages such as poor EMI effect, prominent switching peak signal, and high circuit cost.

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