John T Gilmer

US Patent:

42231841, Sep 16, 1980

Filed:

Oct 24, 1978

Appl. No.:

5/954180

Inventors:

John L. Gilmer - Falls Church VA
Joseph F. Rizzo - Lodi NJ

Assignee:

Bell Telephone Laboratories, Incorporated - Murray Hill NJ

International Classification:

H04Q 136

US Classification:

179 16EA

Abstract:

Pulse signals, for example, dial pulses, wink signals or the like, have been corrected to have minimum break and make intervals by employing at least two analog resistor/capacitor type timers, usually connected in tandem. These prior timer arrangements are not readily implemented by employing large-scale integration because of their use of analog circuit components. Indeed, it is desirable to correct pulse signals to have at least minimum break and make intervals (FIG. 2) by employing digital techniques. To this end, a control signal (ENO) for determining the minimum break and make intervals is generated by utilizing a single digital counter (35) and associated logic for controllably supplying first (Y15) and second (Y30) timing signals (from 34) to the counter (36). The frequencies of the first and the second timing signals are selected in relationship to the desired minimum break and make intervals, respectively. An output control circuit (12 or 11 and 12) is jointly responsive to the control signal (ENO) and first (OPR) and second (REL) input signals representative of first and second states, respectively, of a supplied pulse signal for generating a corrected pulse signal (H) having the desired minimum break and make intervals.

US Patent:

42426367, Dec 30, 1980

Filed:

Oct 24, 1978

Appl. No.:

5/954179

Inventors:

John L. Gilmer - Falls Church VA
Joseph F. Rizzo - Lodi NJ

Assignee:

Bell Telephone Laboratories, Incorporated - Murray Hill NJ

International Classification:

H03K 520
H04G 136
H04K 117

US Classification:

328 63

Abstract:

Operate/release timing circuits are employed to generate time delayed pulse signals, for example, dial pulses, wink signals and other supervisory signals employed in telecommunications signaling systems. Pulse position and pulse width errors and other problems found in prior operate/release timers are resolved by employing a single digital counter and associated control logic elements. The timing circuit is controllably configured into several timer circuit arrangements including an integrating timer, AM timer, integrating timer including coast option, and AM timer including coast option. With the coast option enabled, initial noise immunity in the pulse signal is realized by resetting the counter to an initial state in response to any discontinuity in the input pulse signal until the input pulse signal is continuously present for a predetermined interval. Pulse break, gap and the like immunity is achieved by controlling the counter to count up for a predetermined interval regardless of the presence or absence of the input pulse signal. Once a valid input pulse has been detected and is terminated a timer output change of state is delayed for a so-called release delay interval.

US Patent:

42270545, Oct 7, 1980

Filed:

Dec 1, 1978

Appl. No.:

5/965471

Inventors:

John L. Gilmer - Falls Church VA

Assignee:

Bell Telephone Laboratories, Incorporated - Murray Hill NJ

International Classification:

H04Q 136

US Classification:

179 16EA

Abstract:

Constant-percent break pulse correctors ensure that the break interval of a dial pulse signal subsists for a substantially constant percentage of the total dial pulse interval, i. e. , break interval plus make interval. The pulse corrector also delays via an operate timer and a release timer initiation of pulse correction cycles and other supervisory functions. Erroneous generation of corrected output dial pulses is effectively eliminated by completely isolating the release timer from the pulse corrector and by controlling the operate timer to generate a single narrow output pulse for initiating only one pulse correction cycle during each valid operate interval. The pulse corrector employs a control arrangement in conjunction with a counter to initiate a pulse correction cycle upon detection of a valid operate interval. Detection of a valid operate interval by the counter reaching a first maximum count also causes the counter to be set to a second count lower than the first maximum count and to be inhibited from counting up until the counter reaches a prescribed initial count. The time interval required to reach the prescribed initial count from the second count is sufficiently long to prevent initiation of erroneous pulse correction cycles in response to noise.