BURGLAR ALARM ACTUATED BY CUT TELEPHONE WIRE

• US 3,852,541 A
• Filed: 08/10/1973
• Issued: 12/03/1974
• Est. Priority Date: 08/10/1973
• Status: Expired due to Term

• Current Assignee: Edmund C. Altenberger
• Original Assignee: Edmund C. Altenberger
• Inventors: Altenberger, Edmund C.
• Primary Examiner(s): Blakeslee, Ralph D.
• Application Number:
  US05/387,462
• Time in Patent Office: 480 Days
• US Class Current: 379/33
• CPC Class Codes: H04M 11/04 with alarm systems, e.g. fire, police or burglar alarm systems

Abstract

A burglar alarm which is actuatable by cutting of a telephone set wire such as located outside of a residence home, the alarm relay switch-actuating circuit being connected to either battery and/or DC-rectified AC-power source, the detector and actuating circuitry of a preferred embodiment including leads of the device being advantageously connectable to telephone wire contacts of either polarity - being connectable to '"'"''"'"''"'"''"'"'either'"'"''"'"''"'"''"'"' positive or negative polarity and thus avoiding problems of erroneous matching of polarity which heretofore would render the alarm device inoperative and/or subject to false-alarms upon line change of polarity during use of the telephone, each lead of the device being inter-connected with the other lead thereof through a bridging telephone(s)-capacitor(s)-discharging resistorinterconnection and each lead thereafter including adjacently thereafter in series a resistor and thereafter continuing-inseries both leads connected to input different terminals (one lead per terminal) of a common full-wave bridge-rectifier having negative and positive output terminals and leads therefrom having in parallel across the positive and negative leads each of a resistor, a zener diode, and a field effect transistor (FET), the negative lead of the bridge-rectifier being connected to the FET gate terminal and to the diode such that electrons are flowable solely from said negative lead to said positive lead, and the positive lead of the bridge-rectifier being connected to each of the FET source and to a base of typically an NPN transistor, the FET drain being connected in series through a fourth resistor and a relay switch coil to the NPN collector and the FET drain being further connected through the fourth resistor to the positive current power source, a relay switch being actuatably closable of an alarm power circuit, the NPN emitter being connected to a negative terminal power source current of the relay alarm switchactuating circuit, and a relay-actuatable switch being operatively connected in series in an alarm circuit.

Claims

1. A telephone set cut-line alarm device, comprising in combination:

separate positive and negative connector leads;

at least each of a first resistor means and a zener diode connected across said leads;

at a corresponding end of each of said connector leads, second and third resistor means connected one per lead in series, and at an opposite end of each respective resistor means each resistor means being connectable to a telephone-set line of optional polarity;

said zener diode being connected for unidirectional electron flow from said negative lead to said positive lead;

a field effect transistor having separate gate, drain and source leads, said gate lead being connected to said zener diode at a negative lead thereof;

first switch means having second circuit input and output switch contacts for turning on and off respectively a first current flow controllable of a first relay-activation circuit-second current flow, said first switch means being operatively connected to one of said source leads and to said drain lead of said field effect transistor;

a first capacitor means having first and second leads at least one of which is operatively connected to said zener diode at a positive terminal thereof such that discharge of potential at said gate takes place whenever telephone line voltage on either of said connector leads is terminated or significantly decreased, such that the gate potential is prior to discharge, of a predetermined magnitude large enough to prevent current flow through said drain to said source;

a second currentflow circuit including in series within said second current-flow circuit a direct current means providable of direct current, first relay means having first-circuit input and output actuation leads connected for activating said first relay means, and said switch of said first switch means, and operatively cOnnected to said source lead;

fourth resistor means connected between said drain lead and one of said first relay means input and output leads; and

said first relay means including alarm-circuit switch contacts, said first relay input lead being connected in series with one of said first switch means second circuit contacts; and

said capacitor means being for attenuating AC current.

2. An alarm device of claim 1, in which said first switch means comprises a base/emitter/collector transistor having base, emitter and collector leads, one of said first switch means second-circuit input and output switch contacts being connected to said emitter lead and the other of said first switch means second circuit input and output switch contacts being connected to said collector lead.

3. An alarm device of claim 2, in which the first lead of said first capacitor means is connected to said zener diode at a positive terminal thereof.

4. An alarm device of claim 3, in which the base/emitter/collector transistor is an NPN transistor, said collector being connected to one of said first relay means input and output leads.

5. An alarm device of claim 3, and an alarm circuit including in series with one-another an electrically responsive alarm, said alarm-circuit switch contacts, and said primary coils.

6. An alarm device of claim 5, in which said direct current means comprises step-down transformer means including primary and secondary coils, and rectifier means for imparting direct current to said second circuit in a flow-direction toward said collector lead, toward said drain lead, from said emitter lead and from said source lead;

and including a second capacitor means connected between said first relay means actuating input lead and output lead.

7. An alarm device of claim 6, in which said alarm circuit is about 110 volts AC, in which said transformer secondary coil is about 12 volts AC, and in which said second current-flow circuit is about 15 volts DC.

8. An alarm device of claim 3, in which said base/emitter/collector transistor is a PNP transistor and in which said emitter lead is connected, in series in said second current-flow circuit.

9. An alarm device of claim 8, and an alarm circuit including in series with one-another an electrically responsive alarm, said alarm-circuit switch contacts, and said primary coils, and in which said direct current means comprises step-down transformer means including primary and secondary coils;

and rectifier means for operatively imparting direct current from said secondary coil to said second circuit in a flow-direction of electrons toward said emitter lead, and toward said source lead; and

including a second capacitor means connected between said first relay means actuating input lead and output lead.

10. An alarm device of claim 9, in which said alarm circuit is about 110 volts AC, in which said transformer secondary coil is about 12 volts AC, and in which said second current flow circuit is about 15 volts DC.

11. An alarm device of claim 1, including bridge rectifying means for attenuating AC current and operatively connected across said positive and negative connector leads and operatively connected between (a) said positive and negative connector leads and (b) the second and third resistor means in series between the second and third resistor means and the positive and negative connector leads, such that at said connected end of each of respective resistor means either positive or negative polarity resulting from interchangeable telephone-set line connections is functionally operative for the alarm device.

12. An alarm device of claim 11, in which said capacitor means comprises two capacitors each at a first terminal thereof connected to a positive terminal of the zener diode and one of the two capacitors connected operatively at its remaining terminal to one of said second and third resistor means and the other of the two capacitors connected operatively at its remainiNg terminal to the other of said second and third resistor means, and said rectifier means including first and second rectifier elements with one thereof connected across said one of the two capacitors and the other rectifier element connected across the other of the two capacitors, the third and fourth rectifier elements one being in series between the negative connector lead and one of said second and third resistor means and the other of the third and fourth rectifier elements of said rectifier means connected in electrical series operatively between the positive connector lead and another of said second and third resistor means.

13. An alarm device of claim 12, and at said opposite ends away from the rectifying means, connected between said second and third resistor means, a fifth resistor means, such that discharge of telephone-set capacitor is prompt thereby avoiding delayed triggering of the first relay means.

14. An alarm device of claim 1, and at said opposite ends away from said connector leads, a fifth resistor means connected between said second and third resistor means, such that discharge of telephone-set capacitors is prompt thereby avoiding delayed triggering of the first relay means.

15. A telephone set cut-line alarm device, comprising in combination:

separate positive and negative connector leads;

connected across said leads at least each of a first resistor means and a zener diode;

at a corresponding end of each of said connector leads, second and third resistor means connected one per lead in series, and at an opposite end of each respective resistor means each resistor means being connectable to a telephone-set line of identical polarity;

said zener diode being connected for unidirectional electron flow from said negative lead to said positive lead;

a field effect transistor having separate gate, drain, and source leads, said gate lead being connected to said zener diode at a negative lead thereof;

first switch means having second circuit input and output switch contacts for turning on and off respectively a first current flow controllable of a first relay-activation circuit-second current flow, said first switch means being operatively connected to one of said source leads and to said drain lead of said field effect transistor;

a first capacitor means having first and second leads, and operatively connected to said zener diode at at-least a positive terminal thereof such that discharge of potential at said gate takes place whenever telephone line voltage on either of said connector leads is terminated or significantly decreased, such that the gate potential is prior to discharge, of a predetermined magnitude large enough to prevent current flow through said drain to said source;

a second current-flow circuit including in series within said second current-flow circuit a direct current means providable of direct current, first relay means having first-circuit input and output actuation leads connected for activating said first relay means, and said switch of said first switch means, and operatively connected to said source lead;

said first relay input lead being connected in series with one of said first switch means second circuit contacts;

fourth resistor means connected between said drain lead and one of said first relay means input and output leads; and

said first relay means including alarm-circuit switch contacts.