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| 1.Triphase Electric-larceny-protection Mechanism |
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 Inventor：Liu Fangbiao |
 Patent Application Number：96206189 |
 Abstract： |
| This utility model is a kind of triphase electric-larceny-protection mechanism preventing electric larceny by changing wire connection of metering mechanism. To monitor total current and current recorded in electric meter by three secondary current transformers, making using of unbalanced induction current caused by electric larceny as working current of current unit, after half-wave rectification, to monitor voltage of electric meter by continuous voltage and phase shifting of capacitance-resistance. The current unit and voltage unit are separately recorded and radio alarm signal can be transmitted so as to prevent from electric larceny conducts such as shifting external electric wire of electric meter which will cause broken circuit, shunting, commutation, transformer inverted running by primary and secondary countercurrent, interchanging of leg of circuit and zero line, loss of phase and change of phase in pressurewire, voltage in zero line and switching off metering mechanism, etc. |
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| 2. Monophase Electric-larceny-protection Mechanism |
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Inventor： Liu Fangbiao |
| Patent Application Number：90204368 |
| Abstract： |
| This utility model is a kind of monophase electric-larceny-protection mechanism preventing electric larceny by changing wire connection of singlephase watt-hours meter. To measure electric larceny current by two current transformers and to monitor zero line of electric meter by monitoring circuit. Because there is powersupply control circuit, this mechanism can still work in low voltage. There are two kinds of control modes, i.e. switch-off-delaying-restore and time-keeping so as to adapt different customers. It can effectively control means of electric larceny such as shifting external electric wire of singlephase watt-hours meter that will cause interconversion of input and output electric wire, shunting out of meter, one live wire& one ground wire, cutting off zero line and shutting off powersupply of the mechanism as well as control wire. |
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| 3.Generator Excitation Equipment |
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Inventor：Liu Fangbiao |
| Patent Application Number：01263833 |
| Abstract： |
| This utility model is a kind of generator excitation equipment that can improve the operation performance of generators under capacitive character load. It is to concatenate a diode between major loop output terminal of original excitation equipment and excitation winding, by means of using voltage drop of diode to make three-terminal semiconductor switch into conduction so as to form a circuit. When there is great deal of capacitive character load in generator, because countercurrent in excitation winding- caused by assist-excitation-function of capacitive current- cannot conduct through diode, while three-terminal semiconductor is still turnon, the countercurrent forms a low voltage circuit. As a result, the assist-excitation-function is impaired and the range of voltage upraising is decreased. Consequently, the operation performance of generators under capacitive character load is improved. |
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