Open circuit protection circuit, open circuit protection method and lighting device

Abstract

The invention discloses an open circuit protection circuit, an open circuit protection method and a lighting device. The open circuit protection circuit is used for a device provided with an LED load, wherein a current source supplies electricity to the LED load. The open circuit protection circuit comprises a switch circuit, a timer circuit and a detection circuit, wherein the switch circuit is connected to two sides of the LED load in parallel; the timer circuit is connected to the switch circuit; the detection circuit is connected to the timer circuit and used for detecting the open circuit state of the LED load. When the LED load breaks down and is in an open circuit state, the open circuit protection circuit operates in the following steps that the detection circuit sends a starting signal to the timer circuit, the timer circuit sends a driving signal with set time to the switch circuit, and the switch circuit enables the LED load to be in a short circuit state in the set time. The open circuit protection circuit can return to normal after faults are eliminated; when multiple LED loads all make poor contact with the circuit or the LED loads are not connected with the circuit, the circuit can also be prevented from being damaged, and meanwhile power consumption of the open circuit protection circuit is relatively low.

Description

technical field [0001] The present application relates to an open circuit protection circuit, an open circuit protection method and a lighting device. Background technique [0002] Due to the electrical characteristics and luminous characteristics of LEDs, current sources are generally used to supply power to LED loads. When the current source is used to supply power to the LED load, if the LED load fails, that is, if a certain LED load (including more than one LED) in the LED load string is damaged, or the entire LED load string is not in good contact with the circuit, it will cause LED damage. The load is in an open state. In the state of open circuit, if no protective measures are taken, the output voltage will rise rapidly, causing other parts of the circuit to be damaged. Therefore, open circuit protection is a very necessary function. [0003] In order to realize the open-circuit protection function, there are many open-circuit protection technologies, one of which ...

AI Technical Summary

Problems solved by technology

This technology can protect the circuit from being damaged, but the thyristor is a semi-controlled device. Once it is turned on, it cannot be disconnected. Therefore, when the LED load on the output side returns to normal, it cannot automatically return to normal working status and cannot support hot plugging. pull

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