US2905861A - Remote alarm circuit for warning lights or the like - Google Patents

Description

J. H. GANZENHUBER REMOTE ALARM CIRCUIT FOR WARNING LIGHTS OR THE LIKE sept. 2z, 1959 Filed Sept. 10, 1958 United States Patent Hee REMOTE ALARM CIRCUIT FOR WARNING LIGHTS R THE LIKE John H. Ganzenhuber, La Canada, Calif.

l Application September 10, 1958, Serial No. 760,272

Claims. (Cl. 315-136) This invention is directed to remote alarm circuits for warning or marker lights and, more particularly, to a circuit which provides a remote indication of the condition of warning lights on a tower or the like and which, where desired, automatically connects a replacement lamp in the lighting circuit when its companion lamp fails.

Antenna towers for television stations, microwave relay stations, radar stations and the like constitute hazards to aircraft in ight. Many governmental agencies have spent large periods of time and great sums of money in attempts to reduce the hazardous nature of such towers. One step which has been taken is the establishment of rigid standards of lighting for such towers and the requirement that any such lighting have a high degree of reliability. Because the towers are generally located at some distance from a manned control point and further,

because some of the towers are so tall as to extend above 'dicating lamps or the like so that when the current for the'series coil is discontinued for an extended period a remote indication of that condition is given. However,

` such relays are expensive and have a limited amount of reliability over long periods of time.

One of the problems that is involved is that in many tower lighting installations the lamps are flashed so that the current flowing to the lamp is intermittent and it is necessary to provide in the alarm or indicating circuits a time delay which prevents actuation of the alarm device when the normal liasrhing operation is occurring but will cause actuation of the alarm device if the lamp burns out.

Therefore, it is an object of this invention to provide 'for a warning light circuit an improved remote indication circuit showing the condition of the warning light.

It is a further object of this invention to provide for a tower lighting system a remote indication circuit which ,will respond to a lamp burn-out condition but will not respond to intermittent ashing of the lamp in the tower lighting circuit.

It is a still further object of this invention to provide for a tower lighting circuit a remote indication and lamp I transfer circuit which will automatically indicate the burning out of one of the lamps in the tower lighting circuit and at the same time will transfer power to a second for auxiliary lamp circuit so as to provide continued and @reliable marking of the tower.

According to the present invention a current transformer has its primary connected in series with the warning lamp circuit and has its secondary connected to the resistive element of a thermal time delay relay which is adjusted to have its response time longer than the time between successive flashes of the warning lamp, where 2,905,861 Patented Sept. 22, 1959 a flashing warning lamp is used, and has its control contacts connected for controlling a remote alarm or indicating device directly or through an auxiliary relay. A lamp transfer relay may be provided with its control winding either shunting the alarm or indicating device or provided with power through the contacts of a relay controlled by the time-delay relay which actuates the alarm or indicating device.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with'further objects and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawings, in which,

Figure 1 is a circuit diagram, partially in block form, showing a remote alarm and lamp transfer circuit according to the present invention.

Figure 2 is a circuit diagram of the alarm circuit portion of the circuit of Figure l.

In Figure l, alternating current power for the warning lamp circuit is applied to terminals 1l) and 11 and flows through contact arm 13 of relay 14, contact terminal 1S with which contact arm 13 is normally in electrical contact, through primary 12, lamp 16 which is located on the tower or obstruction, and circuit interrupter 17, in the event that warning lamp 16 is of the flashing type. Of course, lamp 16 instead of being a sole lamp may be replaced by a plurality of lamps in parallel. Secondary 18 of current transformer 19 is coupled to the input terminal 41 and 42 of heating element 20 in thermal time-delay relay 21. Load resistor 4t) shunts secondary winding 18 of current transformer 19. Controlled contacts 22 and 23 of thermal relay 21 are connected to control terminals 24 and 25 of the remote indicator or alarm 26. Output control terminals 27 and 28 of alarm 26 are coupled to control winding 29 of transfer relay 14. Power to .operate alarm 26 and relay 14 is applied at power input terminals 30 and 31. Alternatively, of course, relay 14 may be controlled directly by contacts 22 and 23 on relay' 21.

The circuit of Figure 1 operates as follows. The alternating current applied to terminals 1li and 11 is applied 'in an interrupted form through the primary 12 of current transformer 19 and the closed contacts 13 and 15 of relay 14 to lamp 16. Circuit interrupter 17 is an electrome- :chanically driven switch of any one of several conventional varieties. The intermittent current owing through lprimary 12 induces a current through the heating element 20 of thermal time-delay relay 21. The heating of element 20 in relay 21 opens the circuit between contacts 22 and 23. Alarm 26 thus remains unactivated as long as a predetermined current flows at least intermittently through primary 12. The response time of relay 21 is longer than the time between successive periods of current llow produced by circuit interrupter 17 so that for normal operation of flashing lamp 16 the contacts 22 and 23 will remain disconnected in the alarm and the alarm 25 will not be actuated. Of course, it is possible to provide in alarm 26 a relay which requires contacts 22 and 23 to be closed during normal operation of the lamp 16 in Vorder that alarm 26 be not actuated and which actuates alarm 26 when contacts 22 and 23 are open circuited. Such a circuit would provide an additional fail-safe fea ture in that if relay 21 ceased to function, alarm 26 would be actuated. Further, the closing of contacts 22 and 23 could be used to actuate an indicator of normal lamp operation. Also, if relay 21 is of the single-pole double-throw type the normally closed contact can be used to activate an alarm, whereas the normally open contact can be used to operate a lights Qn indicator.

electromagnetic relay; rst and second lamp power terminals adapted for the application of electrical power thereto; said rst terminal of each of said lrst and second lamps being connected to said first lamp power terminal; said primary winding having a pair of terminals one connected to said second terminal of said rst lamp and the other coupled to said second lamp power terminal through said first output contact and said input arm of said second electromagnetic relay; said second terminal of said second lamp being coupled to said second output contact of said second electromagnetic relay.

References Cited in the le of this patent UNITED STATES PATENTS

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