US3555530A

US3555530A - Annunciator module with return to normal indicating feature

Info

Publication number: US3555530A
Application number: US679017A
Authority: US
Inventors: Art Lee
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1967-10-30
Filing date: 1967-10-30
Publication date: 1971-01-12
Anticipated expiration: 1988-01-12

Abstract

AN ANNUNCIATOR MODULE ADAPTED FOR SELECTIVE OPERATION WITH EITHER A NORMALLY OPEN OR A NORMALLY CLOSED ALARM CONTACT FOR INDICATING BOTH AN ABNORMAL CONDITION OF A VARIABLE AND A RETURN TO NORMAL CONDITION OF THE VARIABLE. THE MODULE INCLUDES A FIRST RELAY HAVING TWO OPPOSITELY POLED WINDINGS EACH ENERGIZED THROUGH A SEPARATE PAIR OF TERMINALS WITH ONE PAIR OF TERMINALS ADAPTED FOR ASSOCIATION WITH A NORMALLY OPEN ALARM CONTACT AND THE OTHER PAIR OF TERMINALS FOR ASSOCIATION WITH A NORMALLY CLOSED ALARM CONTACT. WHEN A NORMALLY OPEN ALARM CONTACT IS USED, THE OTHER TERMINALS ARE CONNECTED BY A REMOVABLE CONDUCTIVE LINK. THE MODULE INCLUDES A SECOND RELAY CONTROLLED BY THE FIRST RELAY, AND A THIRD RELAY, WITH ALL THREE RELAYS CONTROLLING ALARM MEANS SO THAT THE ALARM MEANS IS ACTUATED BOTH WHEN THE VARIABLE BECOMES ABNORMAL AND WHEN THE VARIABLE SUBSEQUENTLY RETURNS TO NORMAL. A FUNC-

TION TEST SWITCH CONTROLS THE SECOND RELAY TO PERMIT A FUNCTION TEST OF THE SECOND AND THIRD RELAYS AND THE ALARM MEANS, AND THE FIRST RELAY CONTROLS USER''S EXTERNAL INFORMATION CIRCUITS. THE ALARM MEANS INCLUDES AN INDICATING LIGHT WHICH IS ADAPTED FOR CONNECTION TO A POWER SOURCE INDEPENDENT OF THE MAIN POWER SOURCE FOR THE MODULE.

Description

Jan. 12, 1971 A. LEE

ANNUNGIATOR MODULE WITH RETURN To NORMAL INDICATING FEATURE Filed Oct" TUE ART Lsr.

fiAA/M/ A r TORNEY 2 Sheets-Sheet l Jan, 12, 1971 Filed Oct. so, 1967 A. LEE ANNUNCIATOR MODULE WITH RETURN To NORMAL INDICATING FEATURE 2 Sheets-Sheet'Z FIG.Z

RELAY WlNDINGS CONDITION LlGHT HORN N.0.ALARM NQALARM CONTACTS CONTACTS IC 2C [(1 2C IA 15 NORMAL OFF OFF D I E D E D D ABNORMAL FLASH ON ,E. E. D D E D ACKNOWLEDGE ABNORMAL STEADY OFF E E D D E- E.

RETURN TO NORMAL FLASH 0N D E D E D E ACKNOWLEDGFZ RETURN To oFF OFF D F.v D a D D NORMAL Fuucnom TEST FLASH ON D E. D E E D FIG; 5

FIG. 4

IN VEA/I'OE ART [.255

United States Patent US. Cl. 340-2131 23 Claims ABSTRACT OF THE DISCLOSURE An annunciator module adapted for selective operation with either a normally open or a normally closed alarm contact for indicating both an abnormal condition of a variable and a return to normal condition of the variable. The module includes a first relay having two oppositely poled windings each energized through a separate pair of terminals with one pair of terminals adapted for association with a normally open alarm contact and the other pair of terminals for association with a normally closed alarm contact. When a normally open alarm contact is used, the other terminals are connected by a removable conductive link. The module includes a second relay controlled by the first relay, and a third relay, with all three relays controlling alarm means so that the alarm means is actuated both when the variable becomes abnormal and when the variable subsequently returns to normal. A function test switch controls the second relay to permit a function test of the second and third relays and the alarm means, and the first relay controls users external information circuits. The alarm means includes an indicating light which is adapted for connection to a power source independent of the main power source for the module.

BACKGROUND OF THE INVENTION Annunciator modules have been provided for indicating the condition of a variable such as pressure, temperature, etc., and have ordinarily included a relay means responsive to a signal such as the position of an associated alarm contact which is movable in accord with the condition of the associated variable to actuate suitable alarm means when the variable deviates from a normal condition. Prior art designs have made provision for indicating not only an abnormal condition of the associated variable but also a return to normal condition of the variable so that the attendant is alerted when each of these conditions occurs. Such prior art designs generally have been unsatisfactory, being of costly and bulky construction because of the use of expensive special circuits and alarm means heretofore necessary to provide both the abnormal and return to normal indications.

Further, prior art designs with a return to normal indicating feature have made no provision for functional testing of the relays and alarm means while the associated alarm contact is in its normal position. They have also failed to provide for actuation of users external information circuits to permit an indication of the condition of a variable independently of the alarm means. When such external circuits are employed, it is desirable that they remain undisturbed when a function test is being performed.

Attempts have previously been made to provide an annunciator module design with a return to normal indicating feature which can be used interchangeably with either a normally open or a normally closed alarm contact. However, these attempts generally have been unsatisfactory in that they have resulted in modules of complex, costly and ineflicient design. Moreover, previously available designs with a return to normal indicating feature 3,555,530 Patented Jan. 12, 1971 have been inflexible in their application because they haverequired a single power supply. It is desirable that provision be made to permit energization of the light device and associated circuits from a power source independent of the main power source for the module.

OBJECTS OF THE INVENTION It is accordingly a primary object of the present invention to provide a novel and improved annunciator module capable of indicating both an abnormal condition of a variable and a return to normal condition of the variable.

It is another object of the invention to provide a. module according to the preceding object including compact and low cost magnetic reed switch control relays.

It is still another object of the invention to provide a novel and improved annunciator module having a return to normal indicating feature with provision for permitting a functional test of the relays and alarmv means of the module while the associated variable is in normal condition.

It is a'further object of the invention to provide a novel and improved annunciator module having a return to normal indicating feature with provision for controlling users external information circuits to permit an indication of the condition of the associated variable independently of the alarm means.

It is still another object of the invention to provide a novel and improved annunciator module having a return to normal indicating feature with means permitting use of the module in association either with a normally closed or a normally open alarm contact.

It is another object of the invention to provide a novel and improved annunciator module having a return to normal indicating feature and containing an indicating light device and associated control circuits adapted for connection to a power source independent of the main power source for the module.

In carrying out the invention in one preferred form an annunciator module is provided for indicating the condition of an associated varialble and includes first, second, and third relays and a single indicating light device. The module is adapted for association with an external audible horn and the first relay includes two oppositely poled windings and a plurality of contacts, the second and third relays each having a single *winding and a plurality of contacts. The two windings of the first relay are arranged to produce a first magnetic flux condition when either winding alone is energized and a second substantially zero resultant magnetic flux condition when both windings are simultaneously energized or are deenergized. An energizing circuit for one winding of the first relay includes first spaced terminals for association with a normally open alarm contact and an energizing circuit for the other winding of the first relay includes second spaced terminals for association with a normally closed alarm contact. The second terminals are connected by a removable electrooonductive link when the first terminals are associated with a normally open alarm contact.

The arrangement is such that when either type of alarm contact is used and is in its normal condition, the windings of the first relay produce one flux condition to establish certain operating conditions of the associated contacts, and when the alarm contact is in its abnormal condition, the windings produce the other flux condition to establish opposite operating conditions of the associated contacts. Contacts of the first relay are included in energizing circuits for the winding of the second relay, and contacts of all three relays are included in energizing circuits for the indicating light and horn. The first relay also includes contacts for controlling users external information circuits to permit indication of the condition of the associated variable independently of the alarm light and horn. When the alarm contact goes olf normal, the winding of the second relay is energized to cause the light to flash and the horn to sound. A manually operable silence switch is effective when thereafter actuated to energize the winding of the third relay to change the flashing light indication to a steady light indication and to silence the horn. When the alarm contact thereafter returns to normal, the winding of the second relay is deenergized to again cause the light to flash and the horn to sound. A manually operable acknowledge switch is effective when thereafter actuated to deenergize the winding of the third relay to extinguish the light and to silence the horn. A manually operable function test switch is provided to permit energization of the winding of the second relay when the alarm contact is in its normal condition to permit a function test of the second and third relays and the light and horn without disturbing the users external circuits. The light and its energizing circuits are adapted for connection to a power source independent of the main power source for the module.

Other objects and advantages of the invention will become apparent from the following description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram showing an annunciator system comprising two identical modules embodying the invention;

FIG. 2 is a chart showing the sequence of operation of one of the modules of the system of FIG. 1; and

FIGS. 3, 4 and 5 are schematic representations showing respectively the relays C, A and B employed in each of the modules of FIG. 1.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to the drawing FIG. 1 shows a preferred embodiment of an annunciator module schematically illustrated by the broken line rectangle and constructed in accordance with the invention. The module 10 functions to indicate the condition of an associated variable such as temperature, voltage, etc. and is responsive to a signal such as the condition of an alarm contact 11 having first and second conditions representative respectively of normal and abnormal conditions of the associated variable. One or more annunciator modules may be employed in association with one or more variables to function independently to indicate the condition of the associated variable. In the specific embodiment illustrated in FIG. 1 two identical modules 10 and 12 are each associated with a separate one of two variables. Details of design of the module 10 will now be described.

In order to indicate the condition of an associated variable the module 10 includes suitable visual alarm means shown as comprising a single indicating light device .14 forming part of the module. The energization of the light device is controlled such that it is extinguished while the associated variable is in normal condition and is illuminated in response to the associated variable assuming an abnormal condition and also in response to the variable returning to its normal condition. The light device is preferably controlled so that it flashes in response to the occurrence of an abnormal condition and also in response to the occurrence of a return to normal condition of the associated variable. The device 14 may assume any suitable form, such as an incandescent lamp. In its preferred form the device 14 comprises an electroluminescent panel. The alarm means preferably includes an additional audible alarm device shown in the form of a horn 15 which is external to the module and which is in common with a plurality of modules when such are employed. The horn 15 is controlled to be silent while a variable is in normal condition and to emit a sound in response to the variable assuming an abnormal condition and also in response to the variable returning to its normal condition.

In order to control operation of the light device 14 and the horn 15 the module 10 includes control means responsive to the condition of the associated alarm contact 11 for controlling energizing circuits for the light device and horn. In the embodiment illustrated the control means comprises a plurality of electromagnetic relays each having energizable winding means and a plurality of sets of contacts responsive to the condition of energization of the associated winding means. Three relays C, A and B are employed, the relay C being controlled by the alarm contact .11 and in turn controlling the relay A, with all three relays controlling the light device 14 and the horn 15.

In accord with one aspect of the invention provision is made to permit selective use of the module 10 with either a normally open or a normally closed alarm contact. To this end the relay C includes two windings 1C and2C having separate energizing circuit means adapted to be controlled respectively by a normally open alarm contact and a normally closed alarm contact. The windings 1C and 2C and their energizing circuit means are arranged so that when either type of alarm contact is employed, the windings 1C and 2C have conditions of energization resulting in the same first flux condition and the same first operating conditions of associated contacts when the selected alarm contact is in its normal condition, and the windings have conditions of energization resulting in the same second flux condition different from the first flux condition and the same second operating conditions of associated contacts different from the first operating conditions when the selected alarm contact is in its abnormal condition.

In the specific embodiment of the invention illustrated in FIG. 1, the energizing circuit means for windings 1C and 2C include a pair of spaced terminals 17 in series with the winding 1C with the series circuit connected across positive and negative power lines .18 and 19 connected to a suitable power supply 20. The energizing circuit means for the winding 2C includes a pair of spaced terminals 22 in series with the winding 2C with the series circuit connected across the power lines 18 and 19. The terminals 17 cooperate with a normally open alarm contact 11 whereas the terminals 22 cooperate with a normally closed alarm contact (not shown) when such is used instead of a normally open alarm contact. When a normally open alarm contact 11 is employed as shown, a suitable removable electroconductive link 24 is positioned to connect the terminals 22 in place of a normally closed alarm contact so that when the alarm contact 11 is in its normally open condition indicating a normal condition of the associated variable, the winding 1C is deenergized and the winding 2C is energized through the link 24. When the alarm contact 11 moves from its normal position shown to its abnormal position wherein it bridges the terminals 17 in response to an abnormal condition of the associated variable, the winding 1C is thereby energized so that both windings 1C and 2C are energized in response to the variable going off normal. The windings 1C and 2C are oppositely poled so as to produce a first magnetic flux condition when either one of the windings 1C and 2C alone is energized, and to produce a second substantially zero resultant magnetic flux} condition when both windings 1C and 2C are simultaneously energized or are deenergized. When both windings are energized simultaneously, the magnetic fluxes produced thereby effectively cancel each other. Thus, when the normally open alarm contact 11 is in its normal condition, resulting energization of the winding 2C alone establishes the first flux condition, and when the normally open alarm contact 11 is in its abnormal condition, resulting energization of both windings 1C and 2C establishes the second flux condition.

If it is desired to use a normally closed alarm contact instead of a normally open alarm contact, the link 24 is replaced by a normally closed alarm contact (not shown) with the result that when the normally closed alarm contact is in its normal condition the winding 2C is energized and the winding 1C is deenergized thus producing the same first magnetic flux condition as when a normally open alarm contact is used and is in its normal condition. When a normally closed alarm contact is used and is moved to its abnormal open condition, the result is that both windings 1C and 2C are deenergized thus establishing the same second substantially zero resultant magnetic flux condition as when a normally open alarm contact is used and is moved to its abnormal closed condition.

In the following description contact sets of the relays C, A and B are designated by the reference letter used to identify the relay followed by a numerical identification. The designations normally open and normally closed as applied in respect to contacts of the relay C refer to the conditions of the contacts when zero resultant magnetic flux is produced by the winding means of relay C. Therefore, normally closed contacts of relay C are closed when windings 1C and 2C are both energized or deenergized. As applied to contacts of relays A and B, the designations normally open and normally closed refer to the conditions of the contacts when the associated windings are deenergized. In the drawing all contacts are shown in their normally open or closed conditions.

In order to effect certain controlling functions the relay C includes normally closed contact sets C1 and C2 and normally open contact sets C3, C4 and C5 responsive to the magnetic flux conditions produced by windings 1C and 2C. A first energizing circuit for winding 1A of relay A includes the contacts C1 and the winding 1A in series across the power lines 18 and 19. A second energizing circuit for the winding 1A includes a manually operable normally open function test switch 26, a diode 27, the contacts C3, and the winding 1A in series across the power lines 18 and 19. The contacts C1 are connected in parallel circuit relation with the series connection of the switch 26, diode 27, and contacts C3. The contacts C2 and C4 are adapted for connection to users external circuits as will be described hereinafter. The contacts C5 are included in a control circuit containing also a manually operable normally closed acknowledge switch 30, normally open contacts B1 of relay B, a portion 31 of a common bus F and a winding 33 of a flasher and horn relay, all in series across the power lines 18 and 19.

A includesnormally open contact sets A1, A2 and A3 and In order to effect certain controlling functions the relay normally closed contact sets A4 and A5 responsive to magnetic flux conditions produced by winding 1A. The contacts A1 are included in a holding circuit for the wind;- ing 1A containing also normally closed contacts B2 of relay B and a diode 34, all in series across the power lines 18 and .19. The contacts A2 are in series with normally closed contacts B3 of relay B, this series connection being in parallel with the series connection of contacts C5 and B1. The contacts A3 are included in a first energizing circuit for light device 14 containing also normally open contacts B4 of relay B and the light device 14 all in series across additional power lines L1 and L2 connected to a power supply 36. The contacts A4 are included in a second test circuit for light device 14 containing also normally closed contacts B5 of relay B, a portion 38 of a common test bus T, a manually operable normally open light test switch 39, and light device 14 all in series across the power lines L1 and L2. The contacts A5 are included in a third energizing circuit for light device 14 containing light device 14, contacts A4, normally open contacts B6 of relay B, a portion 41 of a common bus I and normally open contacts 43, all in series across the power lines L1 and L2.

The relay B includes in addition to previously mentioned contact sets B1, B2, B3, B4, B5, and B6, normally closed contacts B7 and normally open contacts B8. The contacts B7 are in series with the contacts A3 with such series circuit in parallel with the series connection of contacts A4, B6 and A5. In accord with the invention the winding 1B of relay B is energized through two separate circuits each including a separate manually operable control switch. To this end the normally open contacts B8 are in a first energizing circuit for the winding 1B including the winding 1B and the acknowledge switch 30 all in series across the power lines 18 and 19. A second energizing circuit for the winding 1B includes the winding 1B and a manually operable normally open acknowledge or silence switch 44 in series across the power lines 18 and 19. The switch 44 is in parallel with the series connection of the contacts B8 and the switch 30.

In order to control the light device 14 and the horn 15 the flasher and horn relay includes normally open contacts 45 connected in series with the horn 15 with the series circuit across the power lines 18 and 1'9. A flashing motor 47 is connected in parallel relation with the horn 15 and is effective when energized to oscillate the contacts 43 between open and closed conditions to effect a flashing illumination of light device 14 either when the contacts A3 and B7 are closed or when contacts A4, B6 and A5 are closed. The invention provides that the light device 14 and its energizing circuits are energizable from the power supply 36 independent of the power supply 20 thus increasing the flexibility of application of the module.

In accord with another feature of the invention provision is made for permitting the user of the module 10 to connect any desired circuits to terminals associated with the module 10 for producing informational or con trol functions in accord with the condition of the associated variable independently of the alarm means. To this end the contacts C2 of relay C are connected between a first terminal 50 and a common terminal 51, and the contacts C4 of relay C are connected between the common terminal 51 and a third terminal 52. With the described arrangement, the user may connect circuits to the

terminals

50, 51 and 52 and such circuits will be established and interrupted in accord with the condition of the associated variable inasmuch as such circuits are controlled by relay C which in turn is controlled by the alarm contact.

According to a further aspect of the invention, provision is made for permitting a complete function test of the relays A and B their energizing circuits, the light device 14 and the horn 15 and their energizing circuits when the associated variable is in its normalcondition. Further, such a function test is performed without in any way disturbing the users external circuits which may be connected to

terminals

50, 51 and 52. To this end the winding 1A of the relay A includes a separate energizing circuit containing in series the function test switch 26 and the normally open contacts C3 of relay C which contacts are closed when the associated variable is in its normal condition to thereby permit energization of the winding 1A in response to closure of the switch 26 to perform a function test simulating an abnormal condition of the associated variable.

Operation of the module 10 will now be described. Assume initially that a normally open alarm contact 11 is used and that it is in its illustrated normally open condition indicating that the associated variable is normal. For this condition, the winding 1C of relay C is deenergized whereas the winding 2C is energized through the link 24 which is employed when using a normally open alarm contact. Windings 1C and 2C therefore produce the first flux condition so that contacts C1 and C2 are open, and contacts C3, C4 and C5 are closed. The winding 1A of relay A is thus deenergized so that contacts A1, A2 and A3 are open and contacts A4 and A5 are closed as shown in FIG. 1. Winding 1B of relay B is deenergized because switch 44 is open so that normally open contacts B1, B4, B6 and B8 are open and the normally closed contacts B2, B3, B and B7 are closed. The winding 33 of the flasher and horn relay is deenergized because contacts A2 and B1 are open. The light device 14 is extinguished and the horn is silent because contacts A3, B6 and 45 are open. A function test may be performed under these conditions because contacts C3 are closed. A separate test of the light device may also be performed since contacts A4 and B5 are closed.

Assume now that the normally open alarm contact 11 moves to its closed condition wherein it bridges terminals 17 thereby indicatng that the associated variable has gone off normal. This results in energization of winding 1C of relay C so that both windings 1C and 2C are now energized to provide the second substantially zero resultant magnetic flux condition. This results in closure of contacts C1 to energize winding 1A of relay A, opening of contacts C3 to prevent a function test, closure of contacts C2 and opening of contacts C4 to change the condition of external circuits which may be connected to the

terminals

50, 51 and 52, and opening of contacts C5. Energization of winding 1A or relay A causes closure of its normally open contacts A1, A2 and A3 and opening of its normally closed contacts A4 and A5. Closure of contacts A1 establishes the holding circuit for winding 1A since contacts B2 are closed. Closure of contacts A2 results in energization of winding 33 of the flasher and horn relay through closed contacts A2 and B3 to thereby close contacts 45 and energize the horn 15 and the motor 47. The horn 15 emits an audible sound and the motor 47 causes the contacts 43 to oscillate between open and closed conditions. Closure of contacts A3 results in energization of the light device 14 through closed contacts A3, B7 and the oscillating contacts 43 resulting in flashing of the light. Opening of contacts A4 prevents the performance of a test for the light device 14. Opening of contacts A4 has no affect. At this time the horn 15 is sounding and the light device 14 is flashing to thus alert an operator that the associated variable has gone off normal. The holding circuit for maintaining energization of winding 1A is established to provide a memory system wherein windng 1A willremain energized to flash the light and sound the horn even though the variable has previously returned to normal and winding 1C is deenergized and its contacts C1 are open.

In order to acknowledge the abnormal condition the operator closes the silence switch 44 which establishes a first energizing circuit for winding IE to energize such winding. The switch 44 may be of spring return type and when it is released by the operator and returns to its open position, the winding 1B remains energized be cause contacts B8 closed when winding 1B was energized to thereby establish a second energizing circuit for winding 1B. Energization of winding 1B results in closure of contacts B1 which has no affect at this time, and opening of contacts B2 to interrupt the holding circuit for winding 1A so that winding 1A will be deenergized in response to the variable subsequently returning to normal. Energization of winding 13 also opens contacts B3 to effect deenerigization of winding 33 of the flasher and horn relay to open contacts 45 for silencing the horn and deenergizing the motor 47. Energization of winding 1B also closes contacts B4 and opens contacts B7 whereby the light device 14 is energized to provide a steady illumination. At the same time, contacts B5 open and contacts B6 close without affect. Thus, acknowledgement of the abnormal condition by closing switch 44 silence the horn and effects steady illumination of the light.

In accord with the invention provision is made to automatically actuate the alarm means in response to the variable returning to normal condition after actuation of switch 44. In the preferred embodiment, the return to normal of the variable is indicated by flashing of the light device and sounding of the horn. Assume now that the variable returns to normal subsequent to actuation of switch 44. When this occurs the alarm contact 11 returns to its normally open position thus deenergizing winding 1C which opens contacts C1 and closes contacts C5. Opening of contacts C1 results in deenergization of winding 1A because contacts B2 in its holding had previously opened in response to energization of winding 1B resulting from actuation of switch 44. Closing of contacts C5 effects energization of Winding 33 through now closed contacts B1 to sound the horn and oscillate the contacts 43. Deenergization of winding 1A opens contacts A3 to interrupt the first energizing circuit for the light device across the power lines L1 and L2, and closes contacts A4 and A5 to complete the third energizing circuit for the light device through now closed contacts B6 and the oscillating contacts 43. Accordingly, the horn sounds and the light device is transferred from a steady illumination to effect deenerigization ofthe light device 14 so that the the variable has returned to normal.

In order to acknowledge the return to normal indication the operator opens the acknowledge switch 30 which results in opening the first energizing circuit for the winding IE to deenergize winding 13. The switch 30 may be of the spring return type and when it is released by the operator and returns to its closed position, the winding 1B cannot be reenergized because its earlier deenergization opened contacts B8. Deenergization of winding 1B opens contacts B1 to thereby deenergize the winding 33 to silence the horn. At the same time, contacts B6 open to effect deenergization of the light device 14 so that the light is extinguished. The remaining contacts of relay B assume their normal conditions so that the annunciator circuit is now in its normal standby condition.

Assume now that prior to actuation of the silence switch 44 the abnormal variable had returned to normal. In such event, the holding circuit for winding 1A maintains energization of such winding so that flashing of the light and sounding of the horn continues. Also, subsequent actuation of the switch 44 does not change the alarm indication and results in continued flashing of the light and sounding of the horn. This is explained by considering that closing of switch 44 energizes winding 1B to open contacts B2 in the holding circuit for winding 1A to thereby deenergize winding 1A, contacts C1 having been previously opened in response to the variable returning to normal. Although contacts B3 open to interrupt one energizing circuit for winding 33, contacts B1 close at the same time to maintain energization of the winding 33 through another energizing circuit including previously closed contacts C5. The horn thus continues to sound and the contacts 43 continue to oscillate. Although contacts A3 and B7 open to interrupt the first energizing circuit for light device 14 including oscillating contacts 43, contacts B6 close at the same time to thereby maintain energization of the light device through the third energizing circuit including now closed contacts A4 and A5 and the oscillating contacts 43. Therefore, the light continues to flash. Accordingly, when the operator actuates the switch 44 without changing the flashing light and horn sounding indication, he is advised that the variable had previously returned to normal. He may then actuate the switch 30 to return the annunciator circuit to its normal standby condition.

A pluraity of modules identical to the module 10 may be employed in association with a group of variables and when so employed, the modules have in common certain switches and circuits. The function test switch 26 is connected to each of the modules through a common bus and the acknowledge switch 30 is connected to each of the modules through a common bus D. The silence switch 44 is connected to each of the modules through a common bus S. Also, the winding 33 of the flasher and horn relay is connected to each of the modules through the common bus F and the light test switch 39 is connected to each module through the common bus T.

Although the relays C, A and B may be of any suitable construction, they preferably comprise reed switch relays. Referring to FIG. 3 the relay C is illustrated as comprising a plurality of reed switches each including a plurality of magnetically responsive contacts within a sealed capsule surrounded by the oppositely poled winding 1C and 2C which produce when simultaneously energized magnetic fluxes which essentially cancel. The relay C includes three identical double throw reed switches 62, 63 and 64 including respectively the normally closed and normally open contacts C1 and C3, the normally closed and normally open contacts C2 and C4, and the normally open contacts C5 thereby providing the five contact sets of relay C. The normally closed contacts of reed switch 64 are not used. While any suitable type of double throw reed switch may be employed, it is preferred that the reed switches 62, 63 and 64 comprise the design disclosed in US. Pat. No. 3,117,202.

In accord with Patent 3,117,202 the relay 62 for example has a reed movable between two fixed contacts and a bias ma net M poled as shown biases the reed so that contacts C1 and C3 are respectively normally closed and normally open. When winding 2C is energized by current fiow in the direction indicated by the associated arrows, as it normally is through either the link 24 or a normally closed alarm contact, the fiux so generated over comes the bias magnet flux so that the reed snaps up to open contacts C1 and close contacts C3. When winding 1C is energized in response to closure of normally open alarm contact 11, current flows therethrough in the direction of the associated arrows to produce a flux which essentially cancels the flux produced by winding 2C to establish the second substantially zero resultant flux condition. The results in the reed being attracted down by magnet M to close contacts C1 and open contacts C3. The

switches

63 and 64 operate in the same manner.

FIG. 4 illustrates relay A in the form of a reed switch relay. The relay A includes five contact sets comprised of three normally open contact sets and two normally closed contact sets. As shown in FIG. 4 these contact sets are provided by two identical double throw reed switches 65 and 66 identical to

switches

62, 63 and 64, and two single throw reed switches 67 and 68 which may comprise the design disclosed in US. Pat. 2,289,830, all surrounded by the single winding 1A. Thus, the switch 65 contains normally open and closed contacts A3 and A4, the switch 66 contains normally closed contacts AS. the switch 67 contains normally open contacts A1, and the switch 68 contains normally open contacts A2. The normally open contacts of the switch 66 are not used.

FIG. 5 illustrates the relay B in the form of a reed switch relay comprising four double throw reed switches 71, 72, 73 and 74 each identical to

switches

62, 63 and 64 and forming the four normally closed and four normally open contact sets of relay B. Switch 71 contains the normally closed and open contacts B2 and B1, switch 72 contains the normally closed and open contacts B3 and B4, switch 73 contains the normally closed and open contacts B5 and B6, and switch 74 contains the normally closed and open contacts B7 and B8. The four switches are surrounded by the winding 1B which when energized has current flowing therethrough in the directions indicated by the associated arrows.

Certain structural features disclosed in this application are disclosed and broadly claimed in application Ser. No. 678,913 filed Oct. 30, 1967 by Art Lee and assigned to the same assignee as this application.

Although the invention has been described with reference to certain specific embodiments thereof, numerous modifications are possible and it is desired to cover all modifications falling within the spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An annunciator circuit responsive to a signal having a condition representative of the condition of a variable comprising in combination,

a first relay having a winding and a plurality of contacts,

first means for controlling energization of the first relay winding in accord with the condition of said signal such that said first relay winding is normally deenergized and is energized in response to said variable assuming an abnormal condition,

said first means comprising a control relay having winding means and a plurality of contacts, energizing circuit means for the control relay winding means containing terminals to which said signal is applied, and a first energizing circuit for the first relay winding containing first contacts of said control relay which are open when said variable is normal and which close in response to said variable assuming an abnormal condition,-

a second relay having a winding and a plurality of contacts,

a manually operable normally open first acknowledge switch for controlling energization of the second relay winding, said first switch being effective when closed subsequent to said variable assuming an abnormal condition for energizing said second relay winding,

alarlrjiii means for indicating the: condition of said varifirst alarm control means including contacts of said first and second relays effective in response to said variable assuming an abnormal condition for energizing said alarm means to provide a first alarm indication, and effective in response to subsequent closure of said first switch while said variable is in abnormal condition for energizing said alarm means to provide a second alarm indication different from said first alarm indication,

second alarm control means including other contacts of said first and second relays effective in response to said variable returning to normal condition subsequent to closure of said first switch for energizing said alarm means to provide an alarm indication different from said second alarm indication, and

a manually operable normally closed second acknowledge switch, said second switch being effective when opened subsequent to said variable returning to normal for deenergizing said alarm means.

A circuit as defined in claim 1 including a second energizing circuit for the first relay winding containing second contacts of said control relay which are closed when said variable is normal and which open in response to said variable assuming an abnormal condition, and

a manually operable normally open function test switch in series with said second contacts and the first relay winding.

3. A circuit as defined in claim 2 wherein said alarm means includes an indicating light device, said first alarm control means including a first energizing circuit for said light device containing normally open contacts of said first relay and normally closed contacts of said second relay in series to provide a flashing light indication in response to said variable assuming an abnormal condition, and

a second energizing circuit for said light device containing said normally open contacts of said first relay and normally open contacts of said second relay in series to provide a steady light indication in response to closure of said first switch.

4. A circuit as defined in claim 2 wherein said second switch is connected in series with said second relay winding and with normally open contacts of said second relay,

said first switch being connected in parallel with the series connection of said second switch and said normally open contacts of said second relay, and in series with said second relay winding.

5. A circuit as defined in claim 2 wherein said control 1 1 relay includes third contacts for connection to users eX- ternal circuits.

6. A circuit as defined in claim 2 wherein said control relay winding means comprises first and second windings arranged to produce a first magnetic flux condition when either winding alone is energized, and a second substantially zero resultant magnetic flux condition when both windings are simultaneously energized or are deenergized,

the contacts of said control relay having first operating conditions for said first flux condition and having second different operating conditions for said second flux condition, first spaced terminals in series with said first winding for association with a normally open signal contact,

second spaced terminals in series with said second winding for association with a normally closed signal contact, said second terminals being adapted for connection by a removable electroconductive link which is positioned to connect said second terminals when said first terminals are associated with a normally open signal contact,

said first and second terminals when associated respectively with a normally open signal contact and said link being respectively open and connected so as to effect deenergization of said first winding and energization of said second winding to establish said first flux condition when said normally open signal contact is open, and being respectively connected so as to effect energization of both said first and second windings to establish said second flux condition when the normally open signal contact is closed,

said first and second terminals when said second terminals are associated with a normally closed signal contact being respectively open and connected so as to effect deenergization of said first winding and energization of said second winding to establish said first flux condition when said normally closed signal contact is closed, and being respectively open so as to effect deenergization of both said first and second windings to establish said second flux condition when said normally closed signal contact is open.

7. A circuit as defined in claim 1 wherein said control relay includes third contacts for connection to users external circuits.

8. A circuit as defined in claim 1 wherein said control relay winding means comprises first and second windings arranged to produce a first magnetic flux condition when either winding alone is energized, and a second substantially zero resultant magnetic flux condition when both windings are simultaneously energized or are deenergized,

said first and second terminals when associated respectively with a normally open signal contact and said link being respectively open and connected so as to effect deenergization of said first winding and energization of said second winding to establish said first fiux condition when said normally open signal contact is open, and being respectively connected so as to effect energization of both said first and second windings to establish said second flux condition when the normally open signal contact is closed,

9. A circuit as defined in claim 8 wherein said alarm means includes an indicating light device, said first alarm control means including a first energizing circuit for said light device containing normally open contacts of said first relay and normally closed contacts of said second relay in series to provide a flashing light indication in response to said variable assuming an abnormal condition, and

10. A circuit as defined in claim 8 wherein said second switch is connected in series with said second relay winding and with normally open contacts of said second relay,

11. A circuit as defined in claim 8 wherein said control relay includes third contacts for connection to users external circuits.

12. A circuit as defined in claim 1 wherein said alarm means includes an indicating light device, said first alarm control means including a first energizing circuit for said light device containing normally open contacts of said first relay and normally closed contacts of said second relay in series to provide a flashing light indication in response to said variable assuming an abnormal condition, and

13. A circuit as defined in claim 1 wherein said second switch is connected in series with said second relay winding and with normally open contacts of said second relay,

14. An annunciator circuit responsive to a signal having a condition representative of the condition of a variable comprising in combination,

a first relay having a winding and a plurality of contacts,

first means for controlling energization of the first relay winding in accord with the condition of said signal such that said first relay winding is normally deenerglzed and is energized in response to said variable assuming an abnormal condition,

a second relay having a winding and a plurality of contacts,

alarm means for indicating the condition of said variable,

first alarm control means including contacts of said first and second relays effective in response to said variable assuming an abnormal condition for energizing said alarm means to provide a first alarm indication, and effective in response to subsequent closure of said first switch while said variable is in abnormal condition for energizing said alarm means to provide a second alarm indication different from said first alarm indication,

second alarm control means including other contacts of said first and second relays effective in response to said variable returning to normal condition subsequentto closure of said first switch for energizing said alarm means to provide an alarm indication different from said second alarm indication,

a manually operable normally closed: second acknowledge switch, said second switch being effective when opened subsequent to said variable returning to normal for deenergizing said alarm means,

said second switch being connected in series with said second relay winding and with normally open contacts ofsaid second relay, and 1 said first ,switch being connected in parallel with the series connection of said second switch and said normally open contacts of said second relay, and in series 'with said second relay winding.

15. An annunciator circuit responsive to a signal having a condition representative of the condition of a variable comprising in combination,

a first relay having a winding and a plurality of contacts,

a second relay having a winding and a plurality of contacts,

a manually operable normally open first acknowledge switch for controlling energization of the second relay winding, said first switch being efiective when closed subsequent to said variable assuming anabnormalcondition for energizing said second relay winding,

alarm means for indicating the condition of said variable including an indicating light device,

first alarm control means including contacts of said first and second relays eflFective in response to said variable assuming an abnormal condition for energizing "said alarm means to provide a first alarm indication, and efiective in response to subsequent closure of said first switch while said variable is in abnormal condition for energizing said alarm means to provide a second alarm indication different from said first alarm indication,

said first alarm control means including a first energizing circuit for said light device containing normally open contacts of said first relay and normally closed contacts of said second relay in series to provide a flashing light indication in response to said variable assuming an abnormal condition, and a second energizing circuit for said light device containing said normally open contacts of said first relay and normally open contacts of said second relay in series to provide a steady light indication in response to closure of said first switch,

said alarm control means including other contacts of said first and second relays efiective in response to said variable returning to normal condition subsequent to closure of said first switch for energizing said alarm means to provide an alarm indication different from said second alarni indication,

a manually operable normally closed second acknowledge switch, said second switch being effective when opened subsequent to said variable returning to normal for deenergizing said alarm means,

said second switch being connected in series with said second relay winding and with normally open contacts of said second relay, and

control relay having winding means and a plurality of contacts,

energizing circuit means for the control relay winding means containing terminals to which said signal is applied,

first relay having a winding and a plurality of contacts,

first energizing circuit for the first relay winding containing first contacts of said control relay which are open when said variable is normal and which close in response to said variable assuming an abnormal condition,

second relay having a winding and a plurality of contacts,

manually operable normally open first acknowledge switch,

first energizing circuit for the second relay winding containing said first switch,

manually operable normally closed second acknowledge switch,

second energizing circuit for the second relay winding containing in series said second switch and normally open first contacts of said second relay with the series connection in parallel with said first switch,

oscillatable control contacts, a motor efiective when energized for oscillating said control contacts,

a flasher relay having a winding and a pair of normally open contacts in series with said motor,

first energizing circuit for the flasher relay winding including in series normally open first contacts of said first relay and normally closed second contacts of said second relay,

second energizing circuit for the flasher relay winding including in series normally open third contacts of said second relay and second contacts of said control relay which are closed when the variable is normal and which open in response to the variable assuming an abnormal condition, the series connection of said third contacts of said second relay and said second contacts of said control relay being in parallel with the series connection of said first contacts of said first relay and said second contacts of said second relay,

first energizing circuit for said light device including in series normally open second contacts of said first relay, normally closed fourth contacts of said second relay and said oscillatable contacts,

said first energizing circuit for said flasher relay winding and said first energizing circuit for said light device both being established in response to said variable assuming an abnormal condition whereby said light device provides a flashing indication, second energizing circuit for said light device including in series said second contacts of said first relay and normally open fifth contacts of said second relay,

said second relay winding being energized to establish a third energizing circuit for said light device including in series normally closed third and fourth contacts of said first relay, normally open sixth contacts of said second relay and said oscillatable contacts,

said second energizing circuit for said flasher relay winding and said third energizing circuit for said light device both being established in response to said variable returning to normal condition whereby said light device provides said flashing indication,

said second switch when opened subsequent to said variable returning to normal effecting deenergization of said second relay winding to interrupt said third energizing circuit for said light device.

17. A circuit as defined in claim 16 wherein said alarm means includes an audible horn in parallel with said motor.

18. A circuit as defined in claim 16 including a first power supply,

means connecting said energizing circuits for the windings of said control relay, said first and second relays and said flasher relay to said first power supply for energization therefrom,

a second power supply independent of said first power supply, and

means connecting said energizing circuits for said light device to said second power supply for energization therefrom.

19. A circuit as defined in claim 16 wherein said control relay winding means comprises first and second windings arranged to produce a first magnetic flux condition when either winding alone is energized, and a second substantially zero resultant magnetic flux condition when both windings are simultaneously energized or are deenergized,

said first and second terminals when associated respectively with a normally open sginal contact and said link being respectively open and connected so as to effect deenergization of said first winding and energization of said second Winding to establish said first flux condition when said normally open signal contact is open, and being respectively connected so as to elfect energization of both said first and second windings to establish said second flux condition when the normally open signal contact is closed,

20. A circuit as defined in claim 19 including a second energizing circuit for the first relay winding containing third contacts of said control relay which are closed when said variable is normal and which open in response to said variable assuming an abnormal condition, and

a manually operable normally open function test switch in series with said third contacts of said control relay and the first relay winding.

21. A circuit as defined in claim 20 wherein said control relay includes fourth contacts for connection to users external circuits.

22. A circuit as defined in claim 16 including a. second energizing circuit for the first relay winding containing third contacts of said control relay which are closed when said variable is normal and which open in response to said variable assuming an abnormal condition, and

23. A circuit as defined in claim 16 wherein said control relay includes fourth contacts for connection to users external circuits.

References Cited UNITED STATES PATENTS 2,730,702 l/1956 Marmorstone 3402l3.1 3,234,541 2/1966 Paull 340213.1X 2,701,872 2/1955 Marmorstone 340213.1

THOMAS B. HABECKER, Primary Examiner US. Cl. X.R.

P0405" UNITED STATES PATENT OFFICE 5 9 CERTIFICATE OF CORRECTION Patent No. 3,555,530 Dated January 12, 1971 Inventor(s) Art Lee It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 5, line 49, "A includes normally open contact sets Al, A2 and A3 and" should be canceled.

Column 5, line 51, preceding "normally closed", A includes normally open contact sets Al, A2 and A3 and should be inserted.

Column 7, line 36, "A4" should read A5 Column 7, line 48, the should be inserted after "be of" Column 7, line 59, "deenerigization" should read deenergization Column 7, line 66, "silence" should read silences Column 8, line 16, "effect deenerigization of the light device 14 so" should be canceled.

Column 8, line 16, preceding "that", a flashing illumination to thus alert the operator should be inserted Column 8, line 62, "pluraity" should read plurality Column ll, line 42, "claim 1" should read claim 2 Column 11, line 45, "claim 1" should read claim 2 Column 12, line 31, "claim 1" should read claim 2 Column 12, line 44, "claim 1'' should read claim 2 Column 15, line 43, "sginal" should read signal Signed and sealed this L ,th day of May 1971 (SEAL) Attest:

EDWARD M.FI.ETGHER,JR. WILLIAM E. SGHUYLER Attesting Officer Commissionerof Pat