Method, device and switch for providing short-circuit protection for resistive ac load

Abstract

The invention relates to a method for providing short-circuit protection for a resistive AC load, wherein the load is connected with an AC power supply through an active controlled switch controlled by a controller. The method for providing short-circuit protection for the resistive AC load comprises the following steps of: turning on the active controlled switch within a first conduction angle range; obtaining the mean current value of the load through a current detection circuit; and determining whether the mean current value of the load is greater than a default value or not, wherein, if so, the active controlled switch is controlled to be turned off, and if not, the active controlled switch is controlled to be turned on. The invention also relates to a device and a switch for providing short-circuit protection for the resistive AC load. The method, the device and the switch for providing short-circuit protection for the resistive AC load, which are provided by the invention, have the advantages that: when the switch is required to be turned on, the switch is turned on first within the first conduction angle range which cannot cause damage to the switch and the circuit and then whether the switch is continued to be turned on or not is determined by determining whether the resistive AC load is subjected to a short circuit or not through the obtained current value; therefore, the switch and the circuit which are connected with the load can be protected while the resistive AC load in a short-circuit condition can be detected.