A switching power supply circuit with short circuit protection function

Abstract

The invention discloses a switch power circuit with a short circuit protective function. The switch power circuit with the short circuit protective function comprises a main power switching circuit, a constant-current and constant-voltage control circuit and a short circuit protective circuit. Through the connection of control signals, the main power switching circuit controls an electric energy converting process of a resonance controller chip, power conversion is carried out on voltage signals at a power input end, and output voltage signals are reduced. The constant-current and constant-voltage control circuit is provided with a current loop and a voltage loop, and is used for monitoring voltage signals at the output voltage end of a switch power source in real time and controlling the switch power circuit to work in a constant-current and constant-voltage pattern when short circuit happens to the switch power circuit. When the short circuit happens to the switch power source and the fact that the switch power circuit enters the constant-current and constant-voltage pattern is detected, the short circuit protective circuit transmits overvoltage protective signals, controls the working state of the resonance controller chip and reduces the output voltage signals. The switch power circuit has the advantages of being low in power consumption, resistant to temperature rising, strong in load capacity and wide in application range.

Description

technical field [0001] The invention relates to the field of electronic technology, in particular to a switching power supply circuit with a short-circuit protection function. Background technique [0002] At present, switching power supply has become the mainstream power supply in the market. With the maturity, standardization and internationalization of switching power supply, the international requirements for switching power supply are more stringent. And as the world pays more and more attention to energy and environmental protection issues, the development and application of switching power supplies are also imperative in terms of energy conservation, resource conservation and environmental protection. At the same time, more requirements are put forward for the volume, weight, quality, safety, use environment, centralized monitoring, and parallel expansion of switching power supplies. [0003] At present, the traditional switching power supply does not consider the po...

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Problems solved by technology

[0003] At present, the traditional switching power supply does not consider the power consumption and temperature rise of the switching power supply circuit when the load device (external device or external device) is short-circuited

In order to solve this problem in the prior art, the switching power supply circuit is improved. For example, a self-locking method is adopted for the output short circuit, that is, once the short circuit is detected, the output voltage is turned off, which causes the switching power supply to be reset and turned on to be normal. At the same time, it also reduces the load capacity of the switching power supply; in addition, there is another switching power supply that adopts an isolation (self-recovery) method on the output short circuit to deal with the occurrence of a short circuit

Although this technical solution can play a role of short-circuit protection to a certain extent, it is difficult to achieve parallel expansion and limit the application of switching power supplies without constant current and constant voltage operating mode control.

However, when the output of pure constant current and constant voltage switching power supply is short-circuited, the disadvantage is that the switching power supply (about 1000 watts) generally has a loss of tens of watts, which causes waste of energy, and also causes the temperature rise of the power supply to exceed There are serious safety hazards in accordance with the requirements of safety regulations, and at the same time, it cannot meet the requirements of energy saving and environmental protection

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