Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
226 words
A detector circuit to be used in current measurements and comprising two identically wound toroidal transformers (T 1 ,T 2 ), in which a main current, the primary current (I 1 ), induces magneto-motive forces which in turn are neutralized by other magneto-motive forces induced therein by a compensation current, the secondary current (I 2 ), said detector circuit further including sensing windings (21, 22) wound on each toroid or core (11,12), one of which sensing windings, at least, carries a magnetizing current, the sensing current (I3), from an external current source (23), which sensing current is conducted to a synchronous rectifier (32) to provide a d.c. control signal for said compensation current (I2), characterized in that said two sensing windings (21,22) are wound on said two toroids or cores (11,12) to magnetize them in mutually opposite senses by the sensing current (1 3 ), each of said two sensing windings (21,22) further being divided into two equal subwindings (21a,21a';22b,22b') in such a manner that the ampere-turns of all four subwindings are substantially equal, said subwindings further being connected mutually and to said current source (23) in such a manner that the magnetizing currents through said four subwindings are so controlled by means of gating or switching devices (27,28,29,51-54) that the odd-harmonic components of the magnetizing currents are outbalanced whereas the even-harmonic components thereof are added.
Claim 2
Dependent Claim
226 words
A detector circuit to be used in current measurements and comprising two identically wound toroidal transformers (T 1 ,T 2 ), in which a main current, the primary current (I 1 ), induces magneto-motive forces which in turn are neutralized by other magneto-motive forces induced therein by a compensation current, the secondary current (I 2 ), said detector circuit further including sensing windings (21, 22) wound on each toroid or core (11,12), one of which sensing windings, at least, carries a magnetizing current, the sensing current (I3), from an external current source (23), which sensing current is conducted to a synchronous rectifier (32) to provide a d.c. control signal for said compensation current (I2), characterized in that said two sensing windings (21,22) are wound on said two toroids or cores (11,12) to magnetize them in mutually opposite senses by the sensing current (1 3 ), each of said two sensing windings (21,22) further being divided into two equal subwindings (21a,21a';22b,22b') in such a manner that the ampere-turns of all four subwindings are substantially equal, said subwindings further being connected mutually and to said current source (23) in such a manner that the magnetizing currents through said four subwindings are so controlled by means of gating or switching devices (27,28,29,51-54) that the odd-harmonic components of the magnetizing currents are outbalanced whereas the even-harmonic components thereof are added.
Claim 3
Dependent Claim
169 words
A detector circuit as claimed in claim 1, wherein said subwindings (21a,21a';22b,22b') and said synchronous rectifier (32) are mutually connected through an auxiliary transformer (T 3 ), a primary winding (24) of which at a center-tap (25) thereof is connected to said current source (23) and at outer terminals thereof to said sensing windings (21,22) in such a manner that one of said outer terminals is connected to a plus-terminal of one of said subwindings (21a', 22b) on each toroid or core (11,12) and the other one of said outer terminals to a minus-terminal of the other subwinding (21a,22b') on each toroid or core (11,12), and wherein a secondary winding (31) of said auxiliary transformer (T3) is incorporated as a part of said synchronous rectifier (32), whereas the remaining four terminals of said subwindings (21a,21a';22b,22b') are connected through gating or switching devices (27,28,29) to a control signal generator (30) to supply a symmetric square wave voltage signal to selectively controlling of the magnetizing current through said sensing windings (21,22).
Claim 4
Dependent Claim
116 words
A detector circuit as claimed in claim 1, wherein the subwindings (21a,21a';22b,22b') on each toroid (11,12) respectively, are series connected with a minus-terminal to a plus-terminal thus forming a center tap (45) of each sensing winding (21,22), the center tap of each sensing winding being connected mutually and directly to said synchronous rectifier (32) via a summing resistor or a summing amplifier (46), and wherein each of said sensing windings (21,22) are connected with one of their free terminals to a positive voltage source (47) and with the remaining free terminal to a negative voltage source (48) through suitable current limiting switching means (51-54) to selectively supplying of magnetizing current to said four subwindings (21a, 21a';22b,22b').
Claim 5
Dependent Claim
100 words
A detector circuit as claimed in claim 1, wherein all four subwindings (21a,21a';22b,22b') are series connected in such a manner that the sensing windings (21,22) at their junction (60) are interconnected back-to-back in a magnetical sense, said junction (60) being connected to said synchronous rectifier (32) through a summing resistor or a summing amplifier (46), and the outer terminals of said series connected sensing windings (21,22) each being connected to a positive and a negative voltage source (47,48), respectively, through individual sets of current limiting switching devices (51,52,53,54) to selectively supplying of magnetizing current to said two sensing windings (21,22).