Intelligent life testing methods and apparatus for leakage current protection
First Claim
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 fourth input, a first output, a second output, a third output, a trip switch having two LINE terminals that are electrically coupled to the first input and the second input, respectively, and two LOAD terminals that are electrically coupled to the inputs of an electrical appliance, respectively, a reset circuit having an input that is electrically coupled to the third input, and an output that is electrically coupled to the first output, a trip coil circuit having a switching device having a gate, an anode and a cathode, a first input electrically coupled to the output of the reset circuit and the first output, a second input that is electrically coupled to the fourth input, an output that is electrically coupled to the second output, and a leakage current detection circuit having an output that is electrically coupled to the third output of the leakage current protection device, comprising:
- (i) a microcontroller unit (MCU) having a first input that is electrically coupled to the second output of the leakage current protection device, a second input, a third input that is electrically coupled to the output of the leakage current detection device and the third output of the leakage current protection device, a first output that is electrically coupled to the third input of the leakage current protection device, a second output, a third output, a fourth output that is electrically coupled to the second input of the trip coil circuit and the fourth input of the leakage current protection device, and a power supply input P;
(ii) a power grid signal synchronization monitoring circuit having an input that is electrically coupled to the first output of the leakage current protection device, and an output that is electrically coupled to the second input of the MCU;
(iii) an alarm circuit having an input that is electrically coupled to the third output of the MCU, and a power supply input;
(iv) a power supply circuit having an input that is electrically coupled to the first output of the leakage current protection device, and an output that is 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 that is electrically coupled to the second output of the MCU, a first output that is electrically coupled to the first input of the leakage current protection device, a second output that is electrically coupled to the second input of the leakage current protection device,wherein, in operation, the power grid signal synchronization monitoring circuit generates a first signal synchronized with an AC power from the first input and the second input of the leakage current protection device to form a power grid signal synchronization signal electrically coupled to the second input of the MCU;
the MCU generates a pulse signal when the power grid signal synchronization signal reduces to a first predetermined threshold value during every positive half-wave of the AC power, and a second signal from the second output to the ground fault simulation unit to generate a simulated ground fault signal;
the leakage current detection circuit generates a third signal in responsive to the simulated ground fault signal and the pulse signal, which is input into the third input of the MCU;
the gate of the switching device receives the pulse signal to turn the switching device into its conductive state during the pulse period; and
the MCU receives a DC voltage at the first input of the MCU, and compares the DC voltage with a second predetermined threshold value to determine whether a fault exists in the leakage current protection device, and activates the alarm circuit if the at least one fault exists.
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Accused Products
Abstract
An apparatus for testing the life of a leakage current protection device having a leakage current detection circuit and a trip mechanism having a switch device. In one embodiment, the apparatus a ground fault simulation unit, a fault detector of the leakage current detection circuit and the trip mechanism, and a life testing detection control unit having an MCU for controlling operation of the fault detector. In operation, a first signal (pulse signal) is sent to the gate of the switching device to generate a first voltage at the cathode of the switching device, a second signal is sent to the ground fault simulation unit to generate a simulated ground fault for the leakage current detection circuit to generate a second voltage at the gate of the switching device, and the first and second voltages are measured to determine whether a fault exists in the leakage current detection circuit and the trip mechanism.
104 Citations
20 Claims
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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 fourth input, a first output, a second output, a third output, a trip switch having two LINE terminals that are electrically coupled to the first input and the second input, respectively, and two LOAD terminals that are electrically coupled to the inputs of an electrical appliance, respectively, a reset circuit having an input that is electrically coupled to the third input, and an output that is electrically coupled to the first output, a trip coil circuit having a switching device having a gate, an anode and a cathode, a first input electrically coupled to the output of the reset circuit and the first output, a second input that is electrically coupled to the fourth input, an output that is electrically coupled to the second output, and a leakage current detection circuit having an output that is electrically coupled to the third output of the leakage current protection device, comprising:
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(i) a microcontroller unit (MCU) having a first input that is electrically coupled to the second output of the leakage current protection device, a second input, a third input that is electrically coupled to the output of the leakage current detection device and the third output of the leakage current protection device, a first output that is electrically coupled to the third input of the leakage current protection device, a second output, a third output, a fourth output that is electrically coupled to the second input of the trip coil circuit and the fourth input of the leakage current protection device, and a power supply input P; (ii) a power grid signal synchronization monitoring circuit having an input that is electrically coupled to the first output of the leakage current protection device, and an output that is electrically coupled to the second input of the MCU; (iii) an alarm circuit having an input that is electrically coupled to the third output of the MCU, and a power supply input; (iv) a power supply circuit having an input that is electrically coupled to the first output of the leakage current protection device, and an output that is 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 that is electrically coupled to the second output of the MCU, a first output that is electrically coupled to the first input of the leakage current protection device, a second output that is electrically coupled to the second input of the leakage current protection device, wherein, in operation, the power grid signal synchronization monitoring circuit generates a first signal synchronized with an AC power from the first input and the second input of the leakage current protection device to form a power grid signal synchronization signal electrically coupled to the second input of the MCU;
the MCU generates a pulse signal when the power grid signal synchronization signal reduces to a first predetermined threshold value during every positive half-wave of the AC power, and a second signal from the second output to the ground fault simulation unit to generate a simulated ground fault signal;
the leakage current detection circuit generates a third signal in responsive to the simulated ground fault signal and the pulse signal, which is input into the third input of the MCU;
the gate of the switching device receives the pulse signal to turn the switching device into its conductive state during the pulse period; and
the MCU receives a DC voltage at the first input of the MCU, and compares the DC voltage with a second predetermined threshold value to determine whether a fault exists in the leakage current protection device, and activates the alarm circuit if the at least one fault exists.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for intelligently 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 fourth input, a first output, a second output, a third output, a trip switch having two LINE terminals that are electrically coupled to the first input and the second input, respectively, and two LOAD terminals that are electrically coupled to the inputs of an electrical appliance, respectively, a reset circuit having an input that is electrically coupled to the third input, and an output that is electrically coupled to the first output, a trip coil circuit having a switching device having a gate, an anode and a cathode, a first input electrically coupled to the output of the reset circuit and the first output, a second input 140a2 that is electrically coupled to the fourth input, an output that is electrically coupled to the second output, and a leakage current detection circuit having an output that is electrically coupled to the third output of the leakage current protection device, comprising the steps of:
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(i) providing a testing device having; (a) a microcontroller unit (MCU) having a first input that is electrically coupled to the second output of the leakage current protection device, a second input, a third input that is electrically coupled to the output of the leakage current detection device and the third output of the leakage current protection device, a first output that is electrically coupled to the third input of the leakage current protection device, a second output, a third output, a fourth output that is electrically coupled to the second input of the trip coil circuit and the fourth input of the leakage current protection device, and a power supply input P; (b) a power grid signal synchronization monitoring circuit having an input that is electrically coupled to the first output of the leakage current protection device, and an output that is electrically coupled to the second input of the MCU; (c) an alarm circuit having an input that is electrically coupled to the third output of the MCU, and a power supply input; (d) a power supply circuit having an input that is electrically coupled to the first output of the leakage current protection device, and an output that is electrically coupled to the power supply input P of the MCU and the power supply input of the alarm circuit; and (e) a ground fault simulation unit having an input that is electrically coupled to the second output of the MCU, a first output that is electrically coupled to the first input of the leakage current protection device, a second output that is electrically coupled to the second input of the leakage current protection device, (ii) generating a power grid synchronization signal that is received at the second input of the MCU, by the power grid signal synchronization monitoring circuit; (iii) producing a pulse signal when the power grid signal synchronization signal reduces to a first predetermined threshold value and a second signal during every positive half-wave of the AC power by the MCU, wherein the pulse signal is output to the gate of the switching device, and wherein the second signal is output to the ground fault simulation unit so as to generate a simulated ground fault signal therein; (iv) generating a third signal in responsive to the simulated ground fault signal, which is received at the third input of the MCU; (v) received the pulse signal at the gate of the switching device to turn the switching device into a conductive state during the pulse period; (v) detecting a DC voltage between the gate and the cathode of the switching device; (vi) comparing the DC voltage to a second predetermined threshold value by the MCU to determine whether a fault exists in the leakage current protection device, wherein the MCU is programmed such that if the DC voltage is greater than the second predetermined threshold value, no fault exists in the leakage current protection device, and if the DC voltage is less than the second predetermined threshold value, a fault exists in the leakage current protection device; and (vii) activating the alarm circuit by the MCU if a fault exists in the leakage current protection device to generate an alarm to alert users of the leakage current protection device. - View Dependent Claims (11)
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12. A leakage current protection device with intelligent life testing, comprising:
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(i) a leakage current protection device having; (A) a first input; (B) a second input; (C) a third input; (D) a fourth input; (E) a first output; (F) a second output; (G) a third output; (H) a trip switch having two LINE terminals that are electrically coupled to the first input and the second input, respectively, and two LOAD terminals that are electrically coupled to the inputs of an electrical appliance, respectively. (I) a reset circuit having an input that is electrically coupled to the third input, and an output that is electrically coupled to the first output; (J) a trip coil circuit having a switching device that has a gate, a anode and a cathode, a first input that is electrically coupled to the output of the reset circuit and the first output, and a second input that is electrically coupled to the fourth input, and an output that is electrically coupled to the second output; and (K) a leakage current detection circuit having a output that is electrically coupled to the third input of the MCU, (ii) a microcontroller unit (MCU) having a first input that is electrically coupled to the second output of the leakage current protection device, a second input, a third input that is electrically coupled to the output of the leakage current detection device and the third output of the leakage current protection device, a first output that is electrically coupled to the third input of the leakage current protection device, a second output, a third output, a fourth output that is electrically coupled to the second input of the trip coil circuit and the fourth input of the leakage current protection device, and a power supply input P; (iii) a power grid signal synchronization monitoring circuit having an input that is electrically coupled to the first output of the leakage current protection device, and an output that is electrically coupled to the second input of the MCU; (iv) an alarm circuit having an input that is electrically coupled to the third output of the MCU, and a power supply input; (v) a power supply circuit having an input that is electrically coupled to the first output of the leakage current protection device, and an output that is electrically coupled to the power supply input P of the MCU and the power supply input of the alarm circuit; and (vi) a ground fault simulation unit having an input that is electrically coupled to the second output of the MCU, a first output that is electrically coupled to the first input of the leakage current protection device, a second output that is electrically coupled to the second input of the leakage current protection device, wherein, in operation, the power grid signal synchronization monitoring circuit generates a first signal synchronized with an AC power from the first input and the second input of the leakage current protection device to form a power grid signal synchronization signal electrically coupled to the second input of the MCU;
the MCU generates a pulse signal when the power grid signal synchronization signal reduces to a first predetermined threshold value during every positive half-wave of the AC power, and a second signal from the second output to the ground fault simulation unit to generate a simulated ground fault signal;
the leakage current detection circuit generates a third signal in responsive to the simulated ground fault signal and the pulse signal, which is input into the third input of the MCU;
the gate of the switching device receives the pulse signal to turn the switching device into its conductive state during the pulse period; and
the MCU receives a DC voltage at the first input of the MCU, and compares the DC voltage with a second predetermined threshold value to determine whether a fault exists in the leakage current protection device, and activates the alarm circuit if the at least one fault exists.- View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
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Specification