Digitally controlled ringer signal generation

• US 5,323,456 A
• Filed: 06/05/1992
• Issued: 06/21/1994
• Est. Priority Date: 06/12/1991
• Status: Expired due to Term

• Current Assignee: Mitel Networks Corporation
• Original Assignee: Zarlink Semiconductor Inc. (Microchip Technology Incorporated)
• Inventors: Oprea, Dan R. F.
• Primary Examiner(s): Dwyer, James L.
• Assistant Examiner(s): WEAVER, SCOTT LOUIS
• Application Number:
  US07/894,632
• Time in Patent Office: 746 Days
• Field of Search: 379/375, 379/373, 379/418, 379/372, 379/252, 379/253, 379/254, 340/384 E, 340/325.44
• US Class Current: 379/375.01
• CPC Class Codes: G08B 3/1025 Paging receivers with audible signalling details
• CPC Class Codes: H04M 19/04 the ringing-current being generated at the substations

Abstract

A method and apparatus, of producing an alarm or ringing signal by providing a first pulse signal having a predetermined pulse width to define an alarm or ringing signal amplitude, and modulating the pulse signal with a second pulse signal having a pulse rate at least an order lower than the frequency of the first pulse signal to define the alarm or ringing signal frequency, averaging the modulated first pulse signal in a loudspeaker voice coil and reproducing the result in the loudspeaker to provide the alarm or ringing signal.

Claims

1. An alarm or ringing signal generator comprising:

(a) means for generating a first pulse signal having a predetermined pulse width for defining an alarm signal amplitude;

(b) means for modulating the first pulse signal with a lower frequency second pulse signal having a frequency defining an alarm or ringing signal frequency;

(c) means for averaging the modulated first pulse signal and acoustically reproducing the averaged modulated pulse signal to produce said alarm signal.

2. An alarm or ringing signal generator as defined in claim 1 in which the acoustically reproducing means is a loudspeaker and in which the averaging means is a voice coil of said loudspeaker.

3. An alarm or ringing signal generator as defined in claim 2 in which the first pulse signal generating means is a binary pulse counter for producing a plurality of count pulses having pulse widths related to a repetitive binary count, and further including means for controlling the lengths of digital pulses with said count pulses to produce said first pulse signal.

4. An alarm or ringing signal generator as defined in claim 3, further including means for generating plural pulse signals each having a different pulse rate being at least an order lower than the pulse rate of said first pulse signal, and means for providing one of said plural pulse signals as said second pulse signal.

5. A method of producing an alarm or ringing signal comprising:

providing a first pulse signal having a predetermined pulse width and frequency to define an alarm or ringing signal amplitude, and modulating the pulse signal with a second pulse signal having a pulse rate at least an order lower than the frequency of the first pulse signal to define the alarm or ringing signal frequency, averaging the modulated first pulse signal and reproducing a result of said averaging in a loudspeaker to provide said alarm or ringing signal.

6. A method as defined in claim 5 in which the averaging and reproducing steps are effected simultaneously by inductance of said loudspeaker.

7. A method as defined in claim 6 including the step of varying the pulse rate of the second pulse signal to provide a warbling alarm or ringing signal.

8. A method as defined in claim 7 including alternating the pulse rate of the second pulse signal between pulse rates.

9. A method of producing a ringing signal for a telephone as defined in claim 5 comprising:

designating a different ringing signal for each of a group of telephone users, storing a digital code defining said first and second pulse signal corresponding to each different ringing signal in a memory, receiving a ringing enable signal from a remote location containing a designation of a particular telephone user, retrieving one of said digital codes corresponding to said designation of said particular user from said memory, and enabling a ringing signal generating means with said one digital code to generate a particular ringing signal corresponding thereto.

10. A method of producing a ringing signal for a telephone as defined in claim 5 comprising:

designating a particular ringing signal having predetermined frequency, cadence and volume as an alarm, storing a digital code defining said first and second pulse signals corresponding to said alarm in a memory, receiving an alarm digital code and enabling a ringing signal generating means with said digital code to generate said particular ringing signal.

11. A method as defined in claim 10 further including designating a different ringing signal for each of a group of telephone users, storing a digital code corresponding to each different ringing signal in said memory, receiving a ringing enable signal from a remote location containing a designation of a particular telephone user, retrieving one of said digital codes corresponding to said designation of said particular user, and enabling a ringing signal generating means with said one digital code to generate a particular ringing signal corresponding thereto.

12. A method as defined in claim 9 in which said different ringing signals are warbled between at least two different frequencies, the different ringing signals having different amplitudes of their different frequencies.

13. A method of producing an alarm signal as defined in claim 5 comprising:

designating a different alarm signal for each person of a group of persons and different alarm conditions, storing a digital code defining said first and second pulse signal corresponding to each different alarm signal in a memory, receiving an alarm enable signal containing a designation of a particular person, retrieving one of said digital codes corresponding to said enable signal from said memory, and enabling an alarm signal generator using said one digital code to generate an unique alarm corresponding to said one digital code.