Loop length compensation circuit

Details Loop length compensation circuit Loop length compensation circuit

1981-12-28

1984-06-05

Pellinen, A. D.

Electricity: power supply or regulation systems

Remote sensing

179 81B, 323315, H04B 336

Patent

active

044530374

ABSTRACT:
A compensation circuit (10) controls the gain of transmit and receive amplifiers (47), (49) as a function of a residual input current (I.sub.res). Circuit (10) includes a constant current source (24) which is connected to produce mirrored constant currents in transistors (26) and (28). The residual current is passed through a resistor (R.sub.loop) to produce a reference voltage. The constant current from the transistor (26) is divided with the first part of the current passing through the resistor (R.sub.loop) and the second part of the current passing through a resistor (50) and a transistor (54). The transistor (54) is connected in a mirror configuration with a transistor (58). When the residual current increases, the current mirrored to transistor (58) decreases. A transistor (32) is connected in parallel with the transistor (58) to receive the remaining current from the transistor (28) which is not drawn by the transistor (58). The transistor (32) serves as the master side of a mirror circuit having slave transistors (38) and (42). The current mirrored to the transistors (38), (42) is drawn from the amplifiers (47), (49) wherein the current through the amplifiers is proportional to the gain thereof. Thus, the gain of the amplifiers is inversely proportional to the residual current thereby compensating the amplifier gain for the length of the telephone line.

REFERENCES:
patent: 3781481 (1973-12-01), Shaffer et al.
patent: 4007340 (1977-02-01), Russell

Affiliated with

Also associated with

Rating

Loop length compensation circuit does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Loop length compensation circuit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Loop length compensation circuit will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1499041