Pulse detector for counting dial generated pulses
AssigneeAerotel Israel
InventorZvi Kamil
Life of this patent
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Abstract
A pulse detector system for reliably counting pulse signals generated by calling party telephone dials. The system includes generating a dial pulse template based on a sample train of pulses. A preferred embodiment uses a pulse amplitude template comprising an amplitude histogram.
Claims19
A dial pulse detector system at a called party's telephone line circuit for reliably counting dial pulse signals generated by a connected calling party's telephone dial, said detector system comprising:
- amplifier means for amplifying said dial pulse signals to provide amplified dial pulse signals at said amplified called party's line circuit, said dial pulse signals forming a modulation envelope of amplified dial pulse signals,
- filter means for filtering said amplified dial pulse signals to limit said envelope to a particular frequency range,
- envelope detector means for detecting the limited envelope,
- analog to digital converter means for converting the detected envelope to digital signals,
- processing means at the called party's line circuit for reliably counting the number of dial pulses generated by the dial at the calling party's line circuit that is attached to said called party's line circuit over telephone lines, and
- said processing means including means for providing dial pulse template means to determine dial pulse time and amplitude characteristics for the dial at the calling party's line circuit based on sample trains of dial pulse signals generated by the dial at the calling party's line circuit.
A detector system for reliably determining a number of pulses generated by a calling telephone dial where the determined number is used as an input to a computer connected to a called telephone, said detector system comprising:
- means for connecting said detector system to the receiver side of the line circuit of said called telephone, and
- means for providing dial pulse template means of time and amplitude characteristics for said calling telephone dial, the lines and connections between the calling telephone dial and the detector system at the called telephone from sample trains of pulses generated by the calling telephone dial.
A pulse detector method for reliably counting dial pulse signals received at a called party's line circuit and generated by a dial in a calling party's telephone line circuit, said dial pulse detector method comprising the steps of:
- amplifying said dial pulse signals to provide amplified dial pulse signals, said amplified dial pulse signals forming a modulation envelope of dial pulse signals,
- filtering said amplified dial pulse signals to limit said envelope to a particular frequency range,
- detecting the limited envelope,
- converting the detected envelope to digital signals,
- counting the digital signals to obtain the number of signals generated by the calling party's telephone dial, and
- said counting step including the step of providing a dial pulse template showing dial pulse characteristics for the calling party's telephone dial based on at least a sample train of dial pulse signals generated at the calling party's telephone dial and using the template for distinguishing dial pulses from noise.
A dial pulse detector system at a called party's telephone line circuit for reliably counting dial pulse signals generated by a telephone dial at a calling party's line circuit, said calling party's line circuit being connected to said called party's line circuit, said detector system comprising:
- (a) amplifier means for amplifying said dial pulse signals to provide amplified dial pulse signals, said amplified dial pulse signals forming a modulation envelope of amplified dial pulse signals;
- (b) filter means for filtering said amplified dial pulse signals to limit said envelope to a particular frequency range;
- (c) envelope detector means for detecting the limited envelope;
- (d) analog to digital converter means for converting the detected envelope to digital signals;
- (e) processing means at the called party's line circuit for processing the digital signals to reliably count the number of dial pulses generated by the dial at the calling party's line circuit when said calling party's line circuit is connected to the called party's line circuit over telephone lines;
- (f) said processing means including means for providing dial pulse template means for the calling party's telephone dial based on two sample trains of dial pulse signals generated by the calling party's telephone dial;
- (g) said template means including means for providing an amplitude template for determining the number of dial pulses as a function of an amplitude characteristic of the dial pulses in said sample trains of dial pulse signals;
- and
- (h) said amplitude characteristic comprising the vertical distance between maxima and minima of an amplitude versus time graph of the sample trains of dial pulse signals.
A pulse detector method for reliably counting dial pulse signals received at a called party's line circuit and generated at a calling party's telephone dial, said method comprising the steps of:
- (a) amplifying the received dial pulse signals;
- (b) said amplified dial pulse signals forming a modulation envelope of signals;
- (c) filtering said amplified dial pulse signals to limit said envelope to a particular frequency range;
- (d) detecting the limited envelope, converting the detected envelope to digital signals;
- (e) counting the number of digital signals generated by the calling party's telephone dial;
- (f) said counting step including the step of providing dial pulse amplitude and time template means for the calling party telephone dial based on amplitude characteristics and time lengths of at least two sample trains of dial pulse signals generated at the calling party's telephone dial and received at the called party's line circuit;
- and
- (g) said amplitude characteristics comprising the distances between maxima and minima of the amplitude versus time graph of the two sample trains of dial pulse signals.
Dependencies are inferred from the claim text.