Multiple point alarm system with two state alarm switches

Claim 2

Direct current operated zone encoder circuitry for connection with normally open and/or normally closed alarm switches for a multiple point alarm system comprising: a common conductor to which one side of each alarm switch connected to the encoder is connected; an output conductor; a plurality of circuit means, one for each alarm switch, connected to said output conductor, each circuit means including a selector switch connecting with the other side of an alarm switch, said selector switch when in one position serving to connect the alarm switch to the circuit means at one point when the alarm switch is of the normally open type to cause said circuit means to present an electrical signal at said output conductor when the normally open alarm switch closes, and said selector switch when in a second position serving to connect the alarm switch to the circuit means at another point when the alarm switch is of the normally closed type to cause said circuit means to present an electrical signal at said output conductor similar to said first mentioned electrical signal, thereby permitting the alarm switches to be connected to the encoder without first requiring knowledge of the type of alarm switch being connected; a resistor having one end connected to said output conductor and the other end connected to said circuit means; said circuit means including a semiconductor device having one electrode connected to said common conduCtor, a second electrode connected to said selector switch when in said second position and a third electrode connected to said selector switch when in said one position; and said circuit means having a diode connected between said third electrode and said resistor.

Claim 3

Direct current operated zone encoder circuitry for connection with normally open and/or normally closed alarm switches for a multiple point alarm system comprising: a common conductor to which one side of each alarm switch connected to the encoder is connected; an output conductor; a plurality of circuit means, one for each alarm switch, connected to said output conductor, each circuit means including a selector switch connecting with the other side of an alarm switch, said selector switch when in one position serving to connect the alarm switch to the circuit means at one point when the alarm switch is of the normally open type to cause said circuit means to present an electrical signal at said output conductor when the normally open alarm switch closes, and said selector switch when in a second position serving to connect the alarm switch to the circuit means at another point when the alarm switch is of the normally closed type to cause said circuit means to present an electrical signal at said output conductor similar to said first mentioned electrical signal, thereby permitting the alarm switches to be connected to the encoder without first requiring knowledge of the type of alarm switch being connected; a resistor having one end connected to said output conductor and the other end connected to said circuit means; said circuit means including a semiconductor device having one electrode connected to said common conduCtor, a second electrode connected to said selector switch when in said second position and a third electrode connected to said selector switch when in said one position; and said circuit means having a diode connected between said third electrode and said resistor.

Claim 4

Direct current operated zone encoder circuitry for connection with normally open and/or normally closed alarm switches for a multiple point alarm system comprising: a common conductor to which one side of each alarm switch connected to the encoder is connected; an output conductor; a plurality of circuit means, one for each alarm switch, connected to said output conductor, each circuit means including a selector switch connecting with the other side of an alarm switch, said selector switch when in one position serving to connect the alarm switch to the circuit means at one point when the alarm switch is of the normally open type to cause said circuit means to present an electrical signal at said output conductor when the normally open alarm switch closes, and said selector switch when in a second position serving to connect the alarm switch to the circuit means at another point when the alarm switch is of the normally closed type to cause said circuit means to present an electrical signal at said output conductor similar to said first mentioned electrical signal, thereby permitting the alarm switches to be connected to the encoder without first requiring knowledge of the type of alarm switch being connected; a resistor having one end connected to said output conductor and the other end connected to said circuit means; said circuit means including a semiconductor device having one electrode connected to said common conduCtor, a second electrode connected to said selector switch when in said second position and a third electrode connected to said selector switch when in said one position; and said circuit means having a diode connected between said third electrode and said resistor.

Claim 5

Direct current operated zone encoder circuitry for connection with normally open and/or normally closed alarm switches for a multiple point alarm system comprising: a common conductor to which one side of each alarm switch connected to the encoder is connected; an output conductor; a plurality of circuit means, one for each alarm switch, each circuit means including a selector switch, a semiconductor device and a pulse forming means, said selector switch connecting with the other side of an alarm switch, said selector switch being placed in one position when a normally open alarm switch is connected to said switch and being placed in a second position when a normally closed alarm switch is connected to it, said semiconductor device connected to said common conductor, said pulse forming means connected at one end to said output conductor, said pulse forming means connecting at its other end with said selector switch and said semiconductor device, said pulse forming means being energized via said semiconductor device when said selector switch is in said one position and the connected alarm switch initially moves to the alarm position to produce an electrical pulse at said output conductor and being energized via said selector switch and the connected alarm switch when said selector switch is in said other position and the connected alarm switch initially moves to the alarm position to produce an electrical pulse at said output conductor; a resistor having one end connected to said output conductor; and said circuit means including a diode connected between said other end of said pulse forming means and the other end of said resistor, said diode having its anode connected to said other end of said pulse forming means.

Claim 6

Direct current operated zone encoder circuitry for connection with normally open and/or normally closed alarm switches for a multiple point alarm system comprising: a common conductor to which one side of each alarm switch connected to the encoder is connected; an output conductor; a plurality of circuit means, one for each alarm switch, each circuit means including a selector switch, a semiconductor device and a pulse forming means, said selector switch connecting with the other side of an alarm switch, said selector switch being placed in one position when a normally open alarm switch is connected to said switch and being placed in a second position when a normally closed alarm switch is connected to it, said semiconductor device connected to said common conductor, said pulse forming means connected at one end to said output conductor, said pulse forming means connecting at its other end with said selector switch and said semiconductor device, said pulse forming means being energized via said semiconductor device when said selector switch is in said one position and the connected alarm switch initially moves to the alarm position to produce an electrical pulse at said output conductor and being energized via said selector switch and the connected alarm switch when said selector switch is in said other position and the connected alarm switch initially moves to the alarm position to produce an electrical pulse at said output conductor; a resistor having one end connected to said output conductor; and said circuit means including a diode connected between said other end of said pulse forming means and the other end of said resistor, said diode having its anode connected to said other end of said pulse forming means.

Claim 7

A multiple point alarm system for monitoring at a central station a plurality of remote zone encoders, each connected to a plurality of alarm switches comprising: a d.c. voltage supply at the central station having at least two output levels; each zone encoder having a common input conductor; means connecting one of said d.c. supply output levels to said common input conductor; each zone encoder having a zone output and an alarm point output for each alarm switch connected to an encoder, a zone encoder presenting an electrical signal at said zone output when an alarm switch connected to the encoder moves to the alarm position, a zone encoder also presenting a d.c. path between said zone output and an alarm point output when the alarm switch for the alarm point output is in the alarm position; a plurality of zone indicating circuit means at the central station, one for each zone encoder, each zone indicating circuit means having an input; a zone output conductor for each zone encoder connecting the zone output of a zone encoder to the input of a zone indicating circuit means; a plurality of alarm point indicating circuit means at the central station each connected to one of said alarm point outputs in each of said zone encoders, each of said alarm point indicating circuit means requiring the other of said two output levels of said d.c. voltage supply to be applied to place the alarm indicating circuit means in operation; and a normally open switch at the central station for each of said zone indicating circuit means, said switch for a given zone indicating circuit means connecting the other of said two output levels of said d.c. voltage supply to the input of said given zone indicating circuit means when said switch is operated to the closed position, said other of two output levels of said d.c. voltage supply thereby being applied to one of said plurality of alarm point indicating circuit means via said zone output conductor connected to said given zone indicating circuit means to the connected zone encoder and thence via said d.c. path presented in a zone encoder by an alarm switch in the alarm position and the associated alarm point output.

Claim 8

A multiple point alarm system for monitoring at a central station a plurality of remote zone encoders, each connected to a plurality of alarm switches comprising: a d.c. voltage supply at the central station having at least two output levels; each zone encoder having a common input conductor; means connecting one of said d.c. supply output levels to said common input conductor; each zone encoder having a zone output and an alarm point output for each alarm switch connected to an encoder, a zone encoder presenting an electrical signal at said zone output when an alarm switch connected to the encoder moves to the alarm position, a zone encoder also presenting a d.c. path between said zone output and an alarm point output when the alarm switch for the alarm point output is in the alarm position; a plurality of zone indicating circuit means at the central station, one for each zone encoder, each zone indicating circuit means having an input; a zone output conductor for each zone encoder connecting the zone output of a zone encoder to the input of a zone indicating circuit means; a plurality of alarm point indicating circuit means at the central station each connected to one of said alarm point outputs in each of said zone encoders, each of said alarm point indicating circuit means requiring the other of said two output levels of said d.c. voltage supply to be applied to place the alarm indicating circuit means in operation; and a normally open switch at the central station for each of said zone indicating circuit means, said switch for a given zone indicating circuit means connecting the other of said two output levels of said d.c. voltage supply to the input of said given zone indicating circuit means when said switch is operated to the closed position, said other of two output levels of said d.c. voltage supply thereby being applied to one of said plurality of alarm point indicating circuit means via said zone output conductor connected to said given zone indicating circuit means to the connected zone encoder and thence via said d.c. path presented in a zone encoder by an alarm switch in the alarm position and the associated alarm point output.

Claim 9

A multiple point alarm system in accordance with claim 3 wherein said d.c. path for each encoder includes a diode in each encoder connected between the zone output and the common input conductor.

Claim 10

A multiple point alarm system for monitoring a plurality of normally open and/or normally closed alarm switches comprising: zone encoder circuit means and zone identification circuit means, means connecting said zone encoder circuit means to said zone identification circuit means comprising a single output from said zone encoder circuit means, said zone encoder circuit means connected to said alarm switches, said zone encoder circuit means providing a single electrical pulse at said single output in response to each movement of any of said alarm switches to the alarm position, said zone encoder circuit means, after one of said electrical pulses is produced, providing a direct current signal at said single output which remains for so long as any of said alarm switches are in the alarm position, said zone identification circuit means having a first, second and third semiconductor means, said first semiconductor means including a gated semiconductor device, said first and third semiconductor means connected to said single output, said first semiconductor means triggered to conduct in response to said electrical pulse, said third semiconductor means conducting in response to said direct current signal, said second semiconductor means connected to said first and third semiconductor means, said second semiconductor means conducting in response to conduction of either of said first and third semiconductor means, and a signal means included in said zone identification circuit means connected to said second semiconductor means, said signal means being energized when said second semiconductor means is conducting.

Claim 11

A multiple point alarm system for monitoring a plurality of normally open and/or normally closed alarm switches comprising: zone encoder circuit means and zone identification circuit means, means connecting said zone encoder circuit means to said zone identification circuit means comprising a single output from said zone encoder circuit means, said zone encoder circuit means connected to said alarm switches, said zone encoder circuit means providing a single electrical pulse at said single output in response to each movement of any of said alarm switches to the alarm position, said zone encoder circuit means, after one of said electrical pulses is produced, providing a direct current signal at said single output which remains for so long as any of said alarm switches are in the alarm position, said zone identification circuit means having a first, second and third semiconductor means, said first semiconductor means including a gated semiconductor device, said first and third semiconductor means connected to said single output, said first semiconductor means triggered to conduct in response to said electrical pulse, said third semiconductor means conducting in response to said direct current signal, said second semiconductor means connected to said first and third semiconductor means, said second semiconductor means conducting in response to conduction of either of said first and third semiconductor means, and a signal means included in said zone identification circuit means connected to said second semiconductor means, said signal means being energized when said second semiconductor means is conducting.

Claim 12

A multiple point alarm system in accordance with claim 5 further including a multivibrator circuit connected to said second semiconductor means, said multivibrator circuit providing a periodic signal to said second semiconductor means causing said second semiconductor means to conduct in accordance with said periodic signal when said second semiconductor means is conducting in response to conduction of said first semiconductor means.

Claim 13

A multiple point alarm system in accordance with claim 5 further including manually operable means when operated terminating conduction of said first semiconductor means permitting movement of another of said alarm switches to the alarm position to provide another electrical pulse to be applied to said first semiconductor means to again trigger said first semiconductor means to conduct.