AC current sensor for measuring electric AC current in a conductor and an indicator system comprising such a sensor
First Claim
1. An AC current sensor (22;
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24;
26) for performing a substantially real time measurement of electric AC current magnitude in a conductor and for generating a non-electrical wave signal as an output, said non-electrical wave signal comprising a series of pulses having a frequency, which is proportional to the magnitude of current measured, said current sensor comprising;
a current responsive unit comprising an inductive wire-wound current transformer (2210), adapted for mounting adjacent to said electric conductor, said inductive wire-wound current transformer (2210) providing electrical power as a driving current for said current sensor;
a sensor circuitry (2220) comprising current level indication circuitry (2222) comprising a current-to-frequency converter adapted to provide said non-electrical wave signal as a substantially real time current level indication pulse signal (CS1) having a pulse width of 0.5 to 5 μ
s and a pulse frequency (Pfcs) that is proportional to the magnitude of said conductor current when it is within a predetermined current interval (I1-I2); and
said sensor circuitry (2220) further comprising a means (2230) for emitting said non-electrical wave signal as an output to a remote detector, said means (2230) further being adapted for providing at least one further non-electrical wave indication signal in form of a current polarity indication signal (POS) to the remote detector, wherein said non-electrical wave signal and at least one further non-electrical wave indication signal are provided simultaneously.
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Accused Products
Abstract
The invention concerns a current sensor (22; 24; 26) for substantially in real time measuring electric current in a conductor. It is suitable for application in an indicator system (1) such as a short circuit indicator system for measuring instantaneous i.e. live current value, power, reactive power, phase angle, polarity, short circuits, in single or averaged values. It comprises current responsive means comprising a current transformer (2210), adapted for mounting adjacent to said electric conductor; and sensor circuitry (2220) comprising means for emitting a non-electrical wave signal as an output; said sensor circuitry (2220) comprises current level converter circuitry (2222) comprising a current-to-frequency converter adapted to provide said non-electrical wave signal as a current level indication pulse signal (CS1) having a pulse frequency (Pfcs) which is proportional to said real time electric conductor current, when the latter is within a predetermined current interval (I1-I2). Thus, a low cost sensor is provided. The invention further relates to an indicator system (1) for an electric conductor comprising at least one of the above mentioned current sensors (22; 24; 26).
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Citations
16 Claims
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1. An AC current sensor (22;
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24;
26) for performing a substantially real time measurement of electric AC current magnitude in a conductor and for generating a non-electrical wave signal as an output, said non-electrical wave signal comprising a series of pulses having a frequency, which is proportional to the magnitude of current measured, said current sensor comprising;a current responsive unit comprising an inductive wire-wound current transformer (2210), adapted for mounting adjacent to said electric conductor, said inductive wire-wound current transformer (2210) providing electrical power as a driving current for said current sensor; a sensor circuitry (2220) comprising current level indication circuitry (2222) comprising a current-to-frequency converter adapted to provide said non-electrical wave signal as a substantially real time current level indication pulse signal (CS1) having a pulse width of 0.5 to 5 μ
s and a pulse frequency (Pfcs) that is proportional to the magnitude of said conductor current when it is within a predetermined current interval (I1-I2); andsaid sensor circuitry (2220) further comprising a means (2230) for emitting said non-electrical wave signal as an output to a remote detector, said means (2230) further being adapted for providing at least one further non-electrical wave indication signal in form of a current polarity indication signal (POS) to the remote detector, wherein said non-electrical wave signal and at least one further non-electrical wave indication signal are provided simultaneously. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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24;
Specification