Dial pulse restorer
First Claim
1. A dial pulse restorer for receiving and restoring telephone dial pulses which may be distorted, and also for discriminating telephone hang-up pulses which may be applied to a telephone line when a remote telephone coupled to said telephone line hangs up, said telephone dial pulses originating as substantially rectangular pulses defined by pairs of transitions, said dial pulse restorer comprising:
- means for receiving at least the pairs of transitions defining each dial pulse and a single transition representing the hang-up pulse;
shaping means for shaping said transitions;
window generating means coupled to said shaping means and responsive to the first transition of a pair of transitions to generate a window pulse having a duration encompassing the expected time of occurrence of the second transition of said pair of transitions;
pulse generating means coupled to said window generating means and enabled by said window pulse and responsive to said second transition to generate a simulated dial pulse of predetermined duration if said second transition is received during said window pulse; and
hang-up pulse discriminating means coupled to said window generating means to produce a disconnect pulse if a transition is not received during said window pulse.
2 Assignments
0 Petitions
Accused Products
Abstract
A dial pulse restorer for receiving and restoring telephone dial pulses which may be distorted, and also for discriminating telephone-hang-up pulses which may be applied to a telephone line when a remote telephone coupled to the telephone line hangs up. A particular use for such a dial pulse restorer is to control the functions of dictation apparatus operatively coupled to one end of the telephone line in response to the operation of the dial mechanism at the remote telephone. The dial pulse restorer comprises a transition pulse generator for generating transition pulses in response to telephone pulse transitions that are received over the telephone line, such telephone pulse transitions being received either in response to telephone dial pulses or to a telephone hang-up pulse. A window generator is responsive to a transition pulse to generate a window pulse of predetermined duration and substantially centered on the expected time of occurrence of the next following transition pulse. A control pulse generator produces a control pulse in the event that the next-following transition pulse occurs during the window pulse duration; and a hang-up pulse detector indicates the receipt of a telephone hang-up pulse if a transition pulse does not occur during the window pulse duration.
30 Citations
19 Claims
-
1. A dial pulse restorer for receiving and restoring telephone dial pulses which may be distorted, and also for discriminating telephone hang-up pulses which may be applied to a telephone line when a remote telephone coupled to said telephone line hangs up, said telephone dial pulses originating as substantially rectangular pulses defined by pairs of transitions, said dial pulse restorer comprising:
-
means for receiving at least the pairs of transitions defining each dial pulse and a single transition representing the hang-up pulse; shaping means for shaping said transitions; window generating means coupled to said shaping means and responsive to the first transition of a pair of transitions to generate a window pulse having a duration encompassing the expected time of occurrence of the second transition of said pair of transitions; pulse generating means coupled to said window generating means and enabled by said window pulse and responsive to said second transition to generate a simulated dial pulse of predetermined duration if said second transition is received during said window pulse; and hang-up pulse discriminating means coupled to said window generating means to produce a disconnect pulse if a transition is not received during said window pulse. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A dial pulse restorer for controlling the functions of dictation apparatus operatively coupled to one end of a telephone line in response to telephone dial pulses which originate from a remote telephone that is connected to the other end of said telephone line and for disconnecting said dictation apparatus from said telephone line when said remote telephone hangs up, said dial pulse restorer comprising:
-
means for generating transition pulses in response to telephone pulse transitions that are received over said telephone line, a pair of said telephone pulse transitions defining a telephone dial pulse and a single telephone pulse transition representing a hang-up pulse that is applied to said telephone line when said remote telephone hangs up; window generating means responsive to the first transition pulse of a pair of transition pulses to generate a window pulse of predetermined duration and substantially centered on the expected time of occurrence of the second transition pulse of said pair; control pulse generating means coupled to said window generating means and to said means for generating transition pulses, and responsive to a transition pulse that is generated during said window pulse duration to produce a control pulse for use in said dictation apparatus; and means for disconnecting said dictation apparatus from said telephone line in response to said window pulse if a transition pulse is not generated during said window pulse duration. - View Dependent Claims (12, 13, 14)
-
-
15. Apparatus for discriminating between telephone dial pulses and a telephone hang-up pulse applied to a telephone line, said telephone dial and hang-up pulses being susceptible to distortion such that at least the transitions that define said telephone dial pulse and the transition that defines said telephone hang-up pulse are received by said apparatus, comprising:
-
shaping means for shaping the received transitions; window pulse generating means coupled to said shaping means and responsive to a transition for generating a window pulse at a predetermined time after said transition and of a duration encompassing the expected time of occurrence of the next following transition; means for generating a simulated telephone dial pulse if a transition occurs during said window pulse; and hang-up pulse detecting means responsive to a generated window pulse for indicating the receipt of a telephone hang-up pulse at a time delayed from said window pulse if a simulated telephone dial pulse is not generated during the time delay interval. - View Dependent Claims (16, 17, 18, 19)
-
Specification