| US 7,525,441 B2 | ||
| Intelligent life testing methods and apparatus for leakage current protection device with indicating means | ||
| Feng Zhang, Shanghai (China); Hongliang Chen, Shanghai (China); Fu Wang, Yueqing Zhejiang (China); Wusheng Chen, Yueqing Zhejiang (China); Yulin Zhang, Shanghai (China); and Huaiyin Song, Yueqing Zhejiang (China) | ||
| Assigned to General Protecht Group, Inc., Zhejiang (China) | ||
| Filed on Oct. 26, 2006, as Appl. No. 11/588,017. | ||
| Claims priority of application No. 2005 1 0132845 (CN), filed on Dec. 27, 2005. | ||
| Prior Publication US 2007/0146945 A1, Jun. 28, 2007 | ||
| This patent is subject to a terminal disclaimer. | ||
| Int. Cl. G08B 21/00 (2006.01) | ||
| U.S. Cl. 340—638 | 21 Claims |
| 1. An apparatus for testing the life of a leakage current protection device, wherein the leakage current protection device
has a first input, a second input, a third input, a first output, a second output, a third output, a reset circuit having
an input and an output electrically coupled to the third input and the first output, respectively, a trip coil circuit having
an input electrically coupled to the output of the reset circuit and the first output, a first output electrically coupled
to the second output and a second output, and a signature signal generating unit having a first input electrically coupled
to the first input, a second input electrically coupled to the second output of the trip coil circuit, and an output electrically
coupled to the third output, comprising:
(i) a microcontroller unit (MCU) having a first input electrically coupled to the second output of the leakage current protection
device, a second input, a first output electrically coupled to the third input of the leakage current protection device, a
second output, and a power supply input P;
(ii) a signal conversion circuit having an input electrically coupled to the third output of the leakage current protection
device, and an output electrically coupled to the second input of the MCU;
(iii) an alarm circuit having an input electrically coupled to the second output of the MCU, and a power supply input;
(iv) a power supply circuit having an input electrically coupled to the first output of the leakage current protection device,
and an output electrically coupled to the power supply input P of the MCU and the power supply input of the alarm circuit;
and
(v) a ground fault simulation unit having an input and an output electrically coupled to the first input and the second input
of the leakage current protection device, respectively,
wherein, in operation, the ground fault simulation unit generates a series of simulated ground faults, the signature signal
generating unit generates a DC voltage indicating the working condition of the leakage current protection device, the signal
conversion circuit receives the DC voltage corresponding to the signal to be received by the second input of the MCU, and
the MCU compares the DC voltage with a predetermined threshold value to determine whether a fault exists in the leakage current
protection device, and activates the alarm circuit if at least one fault exists.
|