Telephone privacy and alerting device
First Claim
1. A telephone privacy and alerting device for connection to a telephone line and a telephone device, comprising:
- a privacy circuit including a voice connecting circuit for connection between the telephone line and the telephone device, said voice connecting circuit having a self-latching switch means having an on and off state; and
voltage breakdown means for turning said self-latching switch means on when a closed circuit is provided through the telephone device and the potential across said telephone line is above a first predetermined threshold, thereby allowing said voice connecting circuit to establish a current path between the telephone line and the telephone device; and
an alerting circuit for connection to said telephone line, said alerting circuit including alarm means for generating an alarm signal when said alarm means receives a first triggering signal and a second triggering signal simultaneously;
current monitoring means responsive to said voice connecting circuit and operatively coupled to said alarm means for providing said first triggering signal when current is present in said voice connecting circuit; and
further voltage breakdown means for connection to said telephone line and operatively coupled to said alarm means for providing said second triggering signal when the potential across said telephone line is below a second predetermined threshold.
1 Assignment
0 Petitions
Accused Products
Abstract
A telephone privacy and alerting device for connection between a common telephone line and a telephone device. The privacy and alerting device includes a privacy circuit to prevent the telephone device from accessing the telephone line when another telephone device is already off-hook, and an alerting circuit to indicate an alarm when the telephone device is off-hook and a further telephone device is also off-hook. The privacy circuit includes a voice connecting circuit for connection between the telephone line and the telephone device, a self-latching switch means connected to the voice connecting circuit having an on and off state, and voltage breakdown means for turning the self-latching switch means on when a closed circuit is provided through the telephone device and the potential across said telephone line is above a first predetermined threshold, thereby allowing the voice connecting circuit to establish a current path between the telephone line and the telephone device. The alerting circuit includes alarm means for generating an alarm signal when the alarm means receives a first triggering signal and a second triggering signal simultaneously, current monitoring means responsive to the voice connecting circuit and operatively coupled to the alarm means for providing the first triggering signal when current is present in the voice connecting circuit, and further voltage breakdown means operatively coupled to the alarm means for providing the second triggering signal when the potential across the telephone line is below a second predetermined threshold.
-
Citations
21 Claims
-
1. A telephone privacy and alerting device for connection to a telephone line and a telephone device, comprising:
-
a privacy circuit including a voice connecting circuit for connection between the telephone line and the telephone device, said voice connecting circuit having a self-latching switch means having an on and off state; and
voltage breakdown means for turning said self-latching switch means on when a closed circuit is provided through the telephone device and the potential across said telephone line is above a first predetermined threshold, thereby allowing said voice connecting circuit to establish a current path between the telephone line and the telephone device; andan alerting circuit for connection to said telephone line, said alerting circuit including alarm means for generating an alarm signal when said alarm means receives a first triggering signal and a second triggering signal simultaneously;
current monitoring means responsive to said voice connecting circuit and operatively coupled to said alarm means for providing said first triggering signal when current is present in said voice connecting circuit; and
further voltage breakdown means for connection to said telephone line and operatively coupled to said alarm means for providing said second triggering signal when the potential across said telephone line is below a second predetermined threshold. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. The telephone privacy and alerting device for connection between a telephone line and a telephone device, comprising:
-
a first rectifier circuit having two AC terminals and two DC terminals, the AC terminals being adapted for series connection between said telephone line and said telephone device; a voice connecting circuit connected between the DC terminals of said first rectifier circuit, said voice connecting circuit including a self-latching switch means having an on and off state; a voltage breakdown circuit connected to the DC terminals of said first rectifier circuit for turning said self-latching switch means on when the potential across said first rectifier circuit exceeds a first predetermined threshold, thereby causing said voice connecting circuit to establish a current path between the DC terminals of said first rectifier circuit; a second rectifier circuit having two AC terminals and two DC terminals, the AC terminals being adapted for connection across said telephone line; an alarm circuit connected to the DC terminals of said second rectifier circuit for generating an alarm signal when said alarm circuit receives a first triggering signal and a second triggering circuit simultaneously; a current monitoring circuit responsive to said voice connecting circuit and operatively coupled to said alarm circuit for providing said first triggering signal when current is present in said voice connecting circuit; and a further voltage breakdown circuit operatively coupled to said alarm circuit for providing said second triggering signal when the potential across said telephone line is below a second predetermined threshold. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
-
-
18. The telephone privacy and alerting device for connection to a common telephone line and one of at least two telephone devices sharing said line, the privacy and alerting device comprising:
-
a voice connecting circuit for connection between a respective telephone device and the telephone line, said circuit including a SCR having an on and off state; means for turning said SCR on when a closed circuit is provided through said respective telephone line operated device, provided the voltage across the telephone line exceeds a first predetermined threshold level, thereby permitting said voice connecting circuit to operate; an alarm circuit for generating a signal on the telephone line that causes an audio sound to be generated by the ear-piece of said respective telephone line operated device when said alarm circuit receives a first triggering signal and a second triggering signal simultaneously; a current monitoring circuit responsive to said voice connecting circuit and operatively connected to said alarm circuit for providing said first triggering signal when current is present in said voice connecting circuit; and a voltage monitoring circuit for connection to the telephone line and operatively connected to said alarm circuit for providing said second triggering signal when the voltage across the telephone line drops below a second predetermined threshold level. - View Dependent Claims (19, 20)
-
-
21. An alerting device for connection to a telephone line and a telephone device, the alerting device comprising:
-
a voice circuit for series connection between the telephone line and the telephone device; an alarm circuit for generating a periodic audio signal in the ear-piece of the telephone device when said alarm circuit receives a first triggering signal and a second triggering signal simultaneously; a current monitoring circuit connected to said voice circuit for detecting the presence of current in said voice circuit, said current monitoring circuit being operatively connected to said alarm circuit for providing said first triggering signal to said alarm circuit when current is present in said voice circuit; and a voltage monitoring circuit for connection to the telephone line for detecting when the voltage across the telephone line drops below a threshold value, said voltage monitoring circuit being operatively connected to said alarm circuit for providing said second triggering signal to said alarm circuit when said voltage is below said threshold.
-
Specification