PROTECTIVE TELEPHONE ALARM SYSTEM

• US 3,710,024 A
• Filed: 11/12/1970
• Issued: 01/09/1973
• Est. Priority Date: 11/12/1970
• Status: Expired due to Term

• Current Assignee: Warrick T. Lacey
• Original Assignee: Warrick T. Lacey
• Inventors: Lacey, Warrick T.
• Primary Examiner(s): Blakeslee, Ralph D.
• Application Number:
  US05/088,583
• Time in Patent Office: 789 Days
• Field of Search: 179/5R,5P,1.1R
• US Class Current: 379/40
• CPC Class Codes: H04M 11/045 using recorded signals, e.g. speech

Abstract

A protective alarm for automatically connecting itself to a telephone line, dialing a remote telephone and delivering an audio message to the remote telephone, in response to an intrusion. The alarm has a magnetic tape and an associated tape player. On the tape is recorded a 5-kilohertz control signal 100 percent modulated by telephone dialing pulses which are followed by an oral message that is superimposed on the continous control signal. A dialing switch connects the audio output of the tape player to the telephone line when an intrusion switch located, for an example in a window, is opened. A bi-polar transistor controls the dialing switch. The transistor is biased to cause the dialing switch to disconnect the telephone from the alarm system. The transistor circuit responds to the presence of the control signal by connecting the alarm to the telephone line when the control signal is present. An intrusion opens an intrusion switch, begins the magnetic tape player which, in turn, permits the modulated control signal to turn the dialing switch on and off and thereby dial a remote phone. The oral message is then delivered to the remote location.

Claims

1. A protective alarm for connection to a telephone line and for automatically dialing a remote telephone and delivering an audio message in response to an intrusion, the alarm comprising:

a. an audio playback means for providing a programmed signal at its output including a control signal and an audio message;

b. an electronically operated electromechanical dialing switch means having an energization coil and connected to couple the audio output of said playback means to said telephone line when said dialing switch means is closed and to disconnect the telephone when said dialing switch means is open and having an input for operating said dialing switch;

c. a control signal responsive circuit means connected between the input of said dialing switch means and said playback means output for causing the closing Of the dialing switch means in response to the presence of said control signal at said output, said control signal responsive circuit means comprising a transistor having its output switching terminals connected to said energization coil and a source of power and having a capacitor connecting the transistor input to the output of said playback means, the transistor being d-c biased to hold the dialing switch means in an open state; and

d. an impedance matching audio transformer connected to couple the output of said playback means to said telephone line, the primary being connected to the output and the secondary being serially connected to said telephone line and said dialing switch means.

2. an audio message superimposed on a continuous control signal b. an electronically operated dialing switch means connected to couple the audio output of said playback means to said telephone line when said dialing switch means is closed and to disconnect the telephone when said dialing switch means is open and having an input for operating said dialing switch;

and c. control signal responsive circuit means, connected between the input of said dialing switch means and said playback means output, for causing the closing of the dialing switch means in response to the presence of said control signal at said output said control signal responsive circuit means having its switch terminals connected between the input to said dialing switch means and a source of power and having an input for operating the control switch means, the control switch input being coupled to the output of playback means.

3. A protective alarm for connection to a telephone line and for automatically dialing a remote telephone and delivering an audio message in response to an intrusion, the alarm comprising:

a. an audio playback means for providing a programmed signal at its output including a control signal and an audio message said playback means comprising a magnetic tape and an associated tape player and said programmed output being recorder on the tape and including in sequence;

4. An alarm according to claim 3 wherein the control signal is a frequency in the range of 5 KHz to 7KHz

5. An alarm according to claim 3 wherein a. an impedance matching audio transformer is connected to couple the output of said tape player to said telephone line, the primary being connected to said output and the secondary being serially connected to said telephone and said dialing switch means;

b. the dialing switch means is a normally closed electromechanical switch having an energization coil;

c. the control switch means is a bipolar transistor being serially connected at its collector and emitter terminals between said energization coil and a source of power for energizing the energization coil when said transistor is in conduction;

d. a capacitor connects the transistor base to said output;

e. a resistance is connected between the collector and the base of the transistor for biasing the transistor in a conducting state and thereby energizing said energization coil to open said dialing switch; and

f. the input circuit of said transistor has a time constant sufficiently longer than the pEriod of said control signal and sufficiently shorter than the period of said dialing pulses that said control signal will charge the capacitor to cut off the transistor in a time interval substantially less than a dialing pulse.

6. An alarm according to claim 5 wherein a. a plurality of intrusion actuated switches are serially connected to a source of power for being actuated to an open circuit condition by an undesired intrusion;

b. at least three electrically operated alarm switches are provided having their actuating input terminals parallel connected to each other and serially connected to said intrusion switches and said source of power, for maintaining the alarm switches in an open condition so long as said intrusion switches remain unopened by an intrusion;

c. one of said alarm switches in a normally closed power connect switch having its switch terminals connected between the source of power and said control switch and said playback means for applying power to the control switch and the playback means when an intrusion switch is opened;

d. another of said alarm switches is a normally closed line connect switch having its switch terminals connected between the telephone line and the protective alarm, for disconnecting the line from the alarm until one of said intrusion switches is opened and for then connecting the line to the alarm; and

e. another of said alarm switches is a normally open, unlatching switch having its switch terminals serially connected to said intrusion switches and to said parallel connected acutating input terminals to maintain the alarm switches in a closed condition after an intrusion switch has been opened.

7. An alarm according to claim 6 wherein an open biased switch is connected between said source of power and said parallel connected actuating input terminals.

8. An alarm according to claim 3 wherein the alarm switches are electromechanical switches having energization coils and the energization coil terminals are the acutating input terminals.