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US 5,479,504 AGranted
Low voltage balanced hybrid circuit with operational amplifiers
AssigneeSharp Kabushiki Kaisha
InventorsTakahiko Nakano, Shinji Hattori
Life of this patent
Estimating the term…
Abstract
A hybrid circuit applies a data sending signal and an inverted data sending signal to the ends of a primary coil, so that the primary coil receives voltages based on the sum of the voltages of the two signals. As a result, the gains of internal amplifiers can be small, thereby maintaining low level voltages in the hybrid circuit. In addition, because the hybrid circuit is balanced, grounding is unnecessary and noise is kept at a low level.
Claims15
A hybrid circuit, comprising:
- two input terminals for respectively receiving a first signal and a second signal, the second signal being an inverted form of the first signal, and for supplying the first signal and the second signal to a telephone line;
- two output terminals for outputting a communication signal received from the telephone line;
- first amplification means for receiving the first signal from one of the two input terminals and for amplifying the first signal;
- second amplification means for receiving the second signal from the other of the two input terminals and for amplifying the second signal;
- first voltage drop means for dropping a first voltage of the first signal amplified by the first amplification means to a second voltage;
- second voltage drop means for dropping a third voltage of the second signal amplified by the second amplification means to a fourth voltage;
- transformer means including a primary coil having an end for receiving the first signal having the second voltage and another end for receiving the second signal having the fourth voltage, and a secondary coil for receiving the communication signal from the telephone line;
- third amplification means for amplifying the first signal having the first voltage and for providing an output;
- fourth amplification means for amplifying the first signal having the second voltage and for outputting a voltage substantially equal to a voltage of the output from the third amplification means;
- fifth amplification means for amplifying the second signal having the third voltage and for providing an output;
- sixth amplification means for amplifying the second signal having the fourth voltage and for outputting a voltage substantially equal to a voltage of the output from the fifth amplification means;
- first comparison means for outputting a difference between the voltage of the output from the third amplification means and the voltage of the output from the fourth amplification means, the first comparison means connected to one of the output terminals;
- and
- second comparison means for outputting a difference between the voltage of the output from the fifth amplification means and the voltage of the output from the sixth amplification means, the second comparison means connected to the other of the output terminals.
11 more elements
A hybrid circuit, comprising:
- two input terminals for respectively receiving a first signal and a second signal and for supplying the first signal and the second signal to a telephone line;
- two output terminals for outputting a communication signal received from the telephone line;
- first voltage drop means for receiving the first signal having a first voltage from one of the two input terminals, and for dropping the first voltage of the first signal to a second voltage;
- second voltage drop means for receiving the second signal having a third voltage from the other of the two input terminals, and for dropping the third voltage of the second signal to a fourth voltage;
- transformer means including a primary coil having an end for receiving the first signal having the second voltage and another end for receiving the second signal having the fourth voltage, and a secondary coil for receiving the communication signal from the telephone line;
- first amplification means for receiving the first signal output from the first voltage drop means and for amplifying the first signal having the second voltage to have an amplified second voltage substantially equal to the first voltage of the first signal and for outputting the first signal having the amplified second voltage;
- second amplification means for receiving the second signal output from the second voltage drop means and for amplifying the second signal having the fourth voltage to have an amplified fourth voltage substantially equal to the third voltage of the second signal and for outputting the second signal having the amplified fourth voltage;
- first comparison means for receiving the first signal having the first voltage and the first signal having the amplified second voltage, and for outputting a difference between the first voltage of the first signal and the amplified second voltage, the first comparison means connected to one of the output terminals;
- and
- second comparison means for receiving the second signal having the third voltage and the second signal having the amplified fourth voltage, and for outputting a difference between the third voltage of the second signal and the amplified fourth voltage, the second comparison means connected to the other of the output terminals.
7 more elements
A hybrid circuit, comprising:
- two input terminals for respectively receiving a first signal and a second signal and for supplying the first signal and the second signal to a telephone line;
- two output terminals for outputting a communication signal received from the telephone line;
- first voltage drop means for receiving a first signal having a first voltage from one of the two input terminals, and for dropping the first voltage of the first signal to a second voltage;
- second voltage drop means for receiving a second signal having a third voltage from the other of the two input terminals, and for dropping the third voltage of the second signal to a fourth voltage;
- transformer means including a primary coil having an end for receiving the first signal having the second voltage and another end for receiving the second signal having the fourth voltage, and a secondary coil for receiving the communication signal from the telephone line;
- third voltage drop means for receiving the first signal having the first voltage and for dropping the first voltage of the first signal to a fifth voltage substantially equal to the second voltage of the first signal;
- fourth voltage drop means for receiving the second signal having the third voltage and for dropping the third voltage of the second signal to a sixth voltage substantially equal to the fourth voltage of the second signal;
- first comparison means for receiving the first signal having the second voltage and the first signal having the fifth voltage and for outputting a difference between the second voltage of the first signal and the fifth voltage, the first comparison means connected to one of the output terminals;
- and
- second comparison means for receiving the second signal having the fourth voltage and the second signal having the sixth voltage and for outputting a difference between the fourth voltage of the second signal and the sixth voltage, the second comparison means connected to the other of the output terminals.
7 more elements
Dependencies are inferred from the claim text.