Output short-circuit protection circuit as well as load drive system and method

Abstract

The invention provides an output short-circuit protection circuit as well as a load drive system and method. The load drive system comprises a drive module and a load, wherein the drive module is a constant-current linear adjuster. The output short-circuit protection circuit comprises a voltage clamp module and a voltage dividing module, wherein the voltage clamp module is connected with the drive module and the load and used for reducing the voltage difference between the load and the input end of an input voltage source to be lower than a preset voltage threshold value in a clamping manner when the output short-circuit phenomenon occurs to the load drive system, so that partial voltage is performed on first sub-input voltage of the load drive system of the constant-current linear adjuster; the voltage dividing module is connected with the drive module and the load and used for liming output current of the load drive system of the constant-current linear adjuster when the output short-circuit phenomenon occurs to the load drive system, so that second sub-input voltage of the load drive system of the constant-current linear adjuster is divided. With the adoption of the output short-circuit protection circuit as well as the load drive system and method, if the short-circuit phenomenon occurs in the constant-current drive process of the load, electronic devices in the constant-current linear adjuster can keep in a safe work range.

Description

technical field [0001] The invention belongs to the technical field of LED driving applications, and relates to a circuit, a driving system and a method, in particular to an output short-circuit protection circuit, a load driving system and a method. Background technique [0002] In existing LED driving applications, constant current linear regulator chips are often used to drive LED light strings with constant current. However, due to the limitation of the chip processing technology, the withstand voltage value of the internal integrated power tube of the linear regulator is limited. In the prior art, a constant current linear regulator chip is used, and a large electrolytic capacitor is connected to the input and output terminals. For example, the total input voltage is 80V, when the output voltage of the LED load is 75V, and the average voltage difference between the LED light string and the voltage input terminal is 80V-75V=5V, the constant current linear regulator chip...

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Problems solved by technology

[0003] However, in some special cases, for example, during the production test of the LED drive power supply, when the input voltage is powered off, a voltage of 80V is stored on the large electrolytic capacitor. At this time, the LEDP is short-circuited to the ground due to manual operation. The voltage difference at the input end is directly stored on the large electrolytic capacitor, which is 80V. At this time, the electronic device in the constant current linear regulator chip will be broken down and the electronic device will be burned out.

[0004] Therefore, how to provide an output short-circuit protection circuit, load driving system and method to solve the short-circuit of the series-connected LED lights to ground due to special circumstances in the prior art. The voltage difference at the terminal is directly caused by the input voltage to breakdown and burn the electronic devices inside the constant current linear regulator and other defects, which has become a technical problem urgently to be solved by practitioners in this field.

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