Charging monitor
First Claim
1. A charging monitor, comprising:
- a switch that is disposed between a load section having a storage battery and an external AC power supply supplying a current to the load section via a plurality of lines and interrupts the supply of the current from the external AC power supply to the load section;
a current detection circuit that outputs a detection signal corresponding to a difference in level between currents flowing through the lines;
a suppression circuit that suppresses a DC component contained in the detection signal;
a filter circuit that filters a plurality of frequency components contained in the detection signal so that attenuation increases as a frequency becomes high;
a rectifier smoothing circuit that rectifies and smoothens an output signal obtained when the detection signal passes through the filter circuit and the suppression circuit; and
an electric leakage determination circuit that detects an electric leakage and shuts off the switch when the level of the signal smoothened by the rectifier smoothing circuit exceeds a preset reference level,wherein the frequency characteristic of the filter circuit is set such that a frequency characteristic of an entire path that reaches the electric leakage determination circuit via the filter circuit, the suppression circuit and the rectifier smoothing circuit corresponds to the relationship between a frequency of a current flowing through a human and a current value perceived by the human.
2 Assignments
0 Petitions
Accused Products
Abstract
A charging monitor has a switch disposed between a load section having a storage battery and an external AC power supply supplying a current to the load section via a plurality of lines and interrupts the supply of the current from the external AC power supply to the load section; a current detection circuit; a suppression circuit that suppresses a DC component contained in the detection signal; a filter circuit that filters a plurality of frequency components contained in the detection signal so that attenuation increases as a frequency becomes high; a rectifier smoothing circuit that rectifies and smoothens an output signal; and an electric leakage determination circuit that detects an electric leakage and shuts off the switch.
48 Citations
19 Claims
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1. A charging monitor, comprising:
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a switch that is disposed between a load section having a storage battery and an external AC power supply supplying a current to the load section via a plurality of lines and interrupts the supply of the current from the external AC power supply to the load section; a current detection circuit that outputs a detection signal corresponding to a difference in level between currents flowing through the lines; a suppression circuit that suppresses a DC component contained in the detection signal; a filter circuit that filters a plurality of frequency components contained in the detection signal so that attenuation increases as a frequency becomes high; a rectifier smoothing circuit that rectifies and smoothens an output signal obtained when the detection signal passes through the filter circuit and the suppression circuit; and an electric leakage determination circuit that detects an electric leakage and shuts off the switch when the level of the signal smoothened by the rectifier smoothing circuit exceeds a preset reference level, wherein the frequency characteristic of the filter circuit is set such that a frequency characteristic of an entire path that reaches the electric leakage determination circuit via the filter circuit, the suppression circuit and the rectifier smoothing circuit corresponds to the relationship between a frequency of a current flowing through a human and a current value perceived by the human. - View Dependent Claims (2, 3, 5, 6, 7, 8, 12, 13, 15)
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4. A charging monitor, comprising:
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a switch that is disposed between a load section having a storage battery and an external AC power supply supplying a current to the load section via a plurality of lines and interrupts the supply of the current from the external AC power supply to the load section; a current detection circuit that outputs a detection signal corresponding to a difference in level between currents flowing through the lines; a suppression circuit that suppresses a DC component contained in the detection signal; a filter circuit that filters a plurality of frequency components contained in the detection signal so that attenuation increases as a frequency becomes high; a rectifier smoothing circuit that rectifies and smoothens an output signal obtained when the detection signal passes through the filter circuit and the suppression circuit; and an electric leakage determination circuit that detects an electric leakage and shuts off the switch when the level of the signal smoothened by the rectifier smoothing circuit exceeds a preset reference level, wherein in the filter circuit, a first input terminal is connected to a first output terminal via a first resistor, a series circuit composed of a first capacitor and a second resistor is connected between a second output terminal connected to a second input terminal and the first output terminal, the filtered signal by the filter circuit is output between the first and second output terminals, and the current detection circuit outputs the detection signal between the first and second input terminals, and wherein the frequency characteristic of the filter circuit is set such that a frequency characteristic of an entire path that reaches the electric leakage determination circuit via the filter circuit, the suppression circuit and the rectifier smoothing circuit corresponds to the relationship between a frequency of a current flowing through a human and a current value perceived by the human.
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9. A charging monitor, comprising:
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a switch that is disposed between a load section having a storage battery and an external AC power supply supplying a current to the load section via a plurality of lines and interrupts the supply of the current from the external AC power supply to the load section; a current detection circuit that outputs a detection signal corresponding to a difference in level between currents flowing through the lines; a suppression circuit that suppresses a DC component contained in the detection signal; a filter circuit that filters a plurality of frequency components contained in the detection signal so that attenuation increases as a frequency becomes high; a rectifier smoothing circuit that rectifies and smoothens an output signal obtained when the detection signal passes through the filter circuit and the suppression circuit; and an electric leakage determination circuit that detects an electric leakage and shuts off the switch when the level of the signal smoothened by the rectifier smoothing circuit exceeds a preset reference level, wherein the current detection circuit is a zero-phase-sequence current transformer that has a detection coil wound around a circular core, and the plurality of lines include one ground line and two AC lines, the switch has relay contacts for individually opening/closing the two AC lines, a sub-ground line splitting from the ground line and the two AC lines are inserted into the circular core of the current detection circuit, on a side closer to the external current power supply than the switch, the charging monitor further has a contact state detector that detects a voltage between each of the AC lines and the sub-ground line inserted into the core, on the side closer to the storage battery than the switch in a state where the switch is opened, and the contact state detector returns an AC component of a current flowing out of each of the AC lines from the sub-ground line to the ground line via the core. - View Dependent Claims (10, 11, 14)
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16. A charging monitor, comprising:
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a switch that is disposed between a load section having a storage battery and an external AC power supply supplying a current to the load section via a plurality of lines and interrupts the supply of the current from the external AC power supply to the load section; a current detection circuit that outputs a detection signal corresponding to a difference in level between currents flowing through the lines; a suppression circuit that suppresses a DC component contained in the detection signal; a filter circuit that filters a plurality of frequency components contained in the detection signal so that attenuation increases as a frequency becomes high; a rectifier smoothing circuit that rectifies and smoothens an output signal obtained when the detection signal passes through the filter circuit and the suppression circuit; and an electric leakage determination circuit that detects an electric leakage and shuts off the switch when the level of the signal smoothened by the rectifier smoothing circuit exceeds a preset reference level, wherein the plurality of lines include one ground line and two AC lines, the switch has relay contacts for individually opening/closing the two AC lines, a sub-ground line splitting from the ground line and the two AC lines are inserted into a circular core of the current detection circuit, on a side closer to the external current power supply than the switch, the charging monitor further has a contact state detector that detects a voltage between each of the AC lines and the sub-ground line inserted into the core, on the side closer to the storage battery than the switch in a state where the switch is opened, and the contact state detector returns an AC component of a current flowing out of each of the AC lines from the sub-ground line to the ground line via the core. - View Dependent Claims (17, 18, 19)
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Specification