An LCDI is a safety protection device installed between a power supply and an electrical equipment, and mainly includes a shielded wire, a leakage current detection unit, a tripping mechanism, and other circuit protection devices. The existing LCDI is usually required to be used in an integrated circuit (IC). For example, CN1988099B has disclosed an LCDI having a fireproof shielded wire. Referring to FIG. 1, the LCDI includes a current leakage detection unit, and when a current leakage accident occurs, an induction coil detects an unbalanced current passing through a live line and a neutral line and then breaks contact between moving and stationary contacts of a tripping mechanism. The LCDI further includes a fireproof unit, which includes two rectifying components respectively connected to the live line and the neutral line of a grid, voltage dropping components respectively connected in series to the two rectifying components, and a fireproof connecting end extending from the voltage dropping components. The LCDI further includes a fireproof shielded wire. The live core and the neutral core are respectively connected to output ends of the live line and the neutral line of the LCDI and are wrapped by a copper braided wire. One end of the copper braided wire is connected to the fireproof connecting end of the fireproof unit. When the copper braided wire contacts the live core and/or the neutral core, the fireproof unit produces a separation from the live line and/or the neutral line, resulting in the unbalanced current passing through the live line and the neutral line, thereby breaking the contact between the moving and stationary contacts of the tripping mechanism.
The above technical solution requires the use of an integrated chip for receiving a signal from the induction coil and outputting the signal after adjustment to control the tripping mechanism, causing the relatively high cost of the entire LCDI. Besides, as the induction coil is used for detecting the leakage current, possibly a tiny leakage current in the circuit cannot be detected, and therefore hidden danger exists.
Therefore, a heretofore unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies.
USPTO Backgrounds
USPTO Backgrounds