| Patent Number |
Title Of Patent |
Date Issued |
| 5161191 |
Encryption system for time division multiplexed networks |
November 3, 1992 |
| An encryption system is provided for interfacing a time division multiplexing (TDM) telecommunications arrangement with an encryption device for the scrambling of data received by the telecommunications arrangement. The telecommunications arrangement produces a TDM data stream format |
| 4362995 |
Method of and apparatus for producing a logarithmic representation of an input voltage |
December 7, 1982 |
| An input voltage is converted into a logarithmic representation thereof by exponentially changing the charge of a capacitor, producing pulses at a rate dependent upon the time taken for the charge to change between the two reference voltages, and counting the pulses during the time taken |
| 4320338 |
Methods of and apparatus for determining the capacitance of a transmission line by integrating l |
March 16, 1982 |
| Apparatus is disclosed for automatically measuring accurately and rapidly alternating and direct voltages, resistance, and capacitance of a telephone line. Direct voltages and relatively high resistances can be determined by filtering out 60 Hz a.c. signals and measuring line current |
| 4317052 |
Apparatus for converting an A.C. input signal to a rectified and smoothed D.C. signal |
February 23, 1982 |
| Offset voltages of a precision rectifier circuit, buffer amplifiers, and an input comparator of a log converter are compensated for by charging a coupling capacitor to the combined total offset voltage of the apparatus. The charging is effected by causing the comparator to operate as a u |
| 4307305 |
Precision rectifier circuits |
December 22, 1981 |
| A precision rectifier circuit includes two differential amplifiers each having a negative feedback path including a diode. Two pnp transistors have their base-emitter paths connected in parallel with the respective diodes and their collectors connected together and via an output resistor |
