Annunciator circuit

Claim 2

An annunciator circuit comprising: a. means for generating an output level signal in response to a sensed abnormal signal condition; b. an audible alarm; c. means for actuating said audible alarm upon initial recognition of the output level signal from said generating means and means responsive to the output level signal for deactuating said audible alarm if said audible alarm is still actuated when the abnormal signal condition is corrected and the output level signal is extinguished; and d. acknowledgement means electrically coupled to said alarm actuating means for deactuating said audible alarm only while the abnormal signal condition is sensed and for the duration of the output level signal.

Claim 3

An annunciator circuit according to claim 1, further comprising: a. visual alarm means; b. a pulse generator; and c. first logic driver means responsive to actuation of said alarm actuating means and output pulse signals from said pulse generator for intermittently driving said visual alarm means, whereby to cause said visual alarm means to flash and thereby produce an intermittent visual alarm indication.

Claim 4

An annunciator circuit according to claim 2, further comprising second logic driver means responsive to the output level signal from said generating means and to deactuation of said alarm actuating means for continuously driving said visual alarm means, whereby to cause said visual alarm means to produce a steady state alarm indication.

Claim 5

An annunciator circuit according to claim 1, wherein said generating means is comprised of a photo-electric transducer for converting the sensed abnormal signal condition in the form of a DC or AC signal to the output level signal which is electrically isolated from the sensed abnormal signal condition.

Claim 6

An annunciator circuit according to claim 1, wherein said generating means is further comprised of a Hall Effect transducer for converting the sensed abnormal signal condition in the form of an AC or DC signal to the output level signal which is electrically isolated from the sensed abnormal signal condition.

Claim 7

An annunciator circuit according to claim 1, wherein said actuating means is comprised of: a. a silicon controlled rectifier having a gate terminal; b. a differentiator circuIt for responding to the initial recognition of the output level signal from said generating means to produce and apply a trigger signal to the gate terminal of said silicon controlled rectifier; and c. a transistor electrically connected in series with said silicon controlled rectifier, said transistor having a base terminal responsive to the output level signal from said generating means for allowing current to pass through said silicon controlled rectifier and said transistor to said audible alarm after the trigger signal has been applied to the gate of said silicon controlled rectifier, for the duration of the output level signal, and prior to deactuation of said alarm actuating means by said acknowledgement means.

Claim 8

An annunciator circuit according to claim 6, wherein said acknowledgement means is comprised of a normally closed switch which is electrically coupled in series with said silicon controlled rectifier and a DC power source, whereby upon opening of said normally closed switch, the flow of current through said silicon controlled rectifier terminates.

Claim 9

An annunciator circuit according to claim 6, further comprising: a. first out signal means generated upon actuation of said alarm actuating means for preventing actuation of other annunciator circuits while current is passing through said silicon controlled rectifier; and b. means responsive to a generated first out signal means of another annunciator circuit for inhibiting the application of a trigger signal to the gate of said silicon controlled rectifier for preventing actuation of said alarm actuating means while an alarm actuating means of the other annunciator circuit is still actuated.

Claim 10

An annunciator card including therein an annunciator circuit, said annunciator circuit comprising: a. means for generating an output level signal in response to a sensed abnormal signal condition; b. means for providing a signal to actuate an audible alarm upon initial recognition of the output level signal from said generating means and means responsive to the output level signal for deactuating said audible alarm if said audible alarm is still actuated when the abnormal signal condition is corrected and the output level signal is extinguished; and c. means within said card for regulating a DC power to said generating means and said alarm actuating means, said means for regulating the D.C. power being electrically coupled to means of other annunicator cards for sharing power therebetween.

Claim 11

An annunciator card including therein an annunciator circuit, said annunciator circuit comprising: a. means for generating an output level signal in response to a sensed abnormal signal condition; b. means for providing a signal to actuate an audible alarm upon initial recognition of the output level signal from said generating means and means responsive to the output level signal for deactuating said audible alarm if said audible alarm is still actuated when the abnormal signal condition is corrected and the output level signal is extinguished; and c. means within said card for regulating a DC power to said generating means and said alarm actuating means, said means for regulating the D.C. power being electrically coupled to means of other annunicator cards for sharing power therebetween.