CHAPTER VI

_Annunciators and Alarms_

=Three Wire Return Call System.= A three wire return call annunciator system is shown in Fig. 60.

There are two battery wires installed, from which taps are taken off and led to each room or push button.

Three way or return call push buttons are used as shown at points marked _B_.

In the diagram, the bells are marked _A_, the drops in the annunciator _D_, the annunciator bell _C_ and the return call buttons in the annunciator _E_. The batteries are as shown at _F_. The heavy black outline encloses the annunciator mechanism and connections which are drawn diagrammatically for the sake of clearness.

Three stations only are shown on the sketch, but the annunciators which are manufactured by Edwards and Co., Inc., of New York, are made in all standard sizes.

=Installing Elevator Annunciators.= The installing of electric bells and annunciators in elevators does not present any special problems, although the apparatus used must be selected with a view to its being suitable to withstand the shocks incident to elevator service.

In general the wires leading from the push buttons on the different floors to the bell or annunciator in the elevator, are flexible and made up into a cable. One end of this cable is attached to the underside of the elevator car, the other end being fixed usually to the elevator wall, at a point midway between the top and bottom of the shaft.

In Fig. 61 is shown a diagram of the general circuit used, details of course differing in each installation.

One point to be taken care of in elevator work is the attachment of the cables. The continual movement tends to break the wires at the two ends if good flexible cable is not used and the installation done in a workmanlike manner.

Elevator cable is a standard article and may be procured through any electrical supply store. That most commonly used consists of the requisite number of copper conductors each composed of 16 strands No. 30 B. and S. gauge soft and untinned copper wire. These flexible conductors are insulated with two reverse wrappings of cotton and one braid of cotton. The insulated conductors are cabled together with a steel supporting strand where extra tensile strength is required, as in the case of extra long cables. The number of conductors generally ranges from 3 to 20 inclusive.

The wires leading from the push buttons to the cable should be preferably rubber covered and braided. Only where economy at the outset is desired may ordinary annunciator or office wires be employed.

A connection block carrying binding posts is used at each point where the cable connects to the push button wires or to the annunciator. This may be home-made or purchased ready made, as desired.

=Burglar Alarm Annunciators.= Although almost any annunciator may be used for open circuit burglar alarm work, they usually do not contain certain devices which are desirable in burglar alarm work.

In Fig. 62 is shown a diagram of a burglar alarm annunciator, the view being schematic of the back board.

The references are as follows: _A_ is the main alarm bell situated wherever desired and connected to the binding posts _BB_. The battery connection leading directly to the battery _K_ is marked _C_ and that leading to the contact spring is marked _D_. The cut-off switch _E_ cuts off the battery while _F_ is the constant ring switch. _G_ is the upper bar and _H_ the lower bar, while the letters _JJ_ denote the indicating drops. The door and window springs are lettered _S_. At _L_ is a switch which may be used to disconnect the entire burglar alarm system. Where it is desired to disconnect only a section at a time, the switch corresponding to the section is turned off the upper bar _G_ and on to the lower bar _H_.

=Clock Alarm Circuit.= A diagram of the wiring and connections on the back board of all clock alarms is illustrated in Fig. 63. This diagram embodies the principles of the last described circuit, but includes the circuit of a clock-operated alarm.

=Bells for High Voltages.= The use of electric bells on lighting circuits is becoming quite general, as it obviates the necessity of using batteries, and thereby simplifies both installation and maintenance.

There is no fundamental objection to operating make and break bells on electric light circuits. Providing the voltage and amperage are the same, there is little difference between the current from a direct-current dynamo and that from a battery. But owing to the higher voltages of the lighting circuit over that generally employed from batteries, the bell coils must be wound to high resistances to keep down the current strength. There are also other slight changes to assist in suppressing sparking, as have been already treated on.

Where the circuit is not over 220 volts, the bells are wound with fine wire and have also self-contained resistance coils. For 500 volts and over, a resistance lamp is connected in with the bell which in this case is wound for a 150-volt circuit.

These bells up to 6-inch and inclusive will operate on circuits of either direct or alternating current.

Above this size it is necessary to use specially constructed bells on alternating current circuits.

Most large hotels and office buildings having direct current lighting service are using it for ringing bells and similar work to the total exclusion of batteries.

Where the number of units to be operated justifies it, motor generators are operated in connection with the lighting mains to produce a low voltage most suitable for the bells. The connections in this case are no different to those when batteries are employed.

=Bell-ringing Transformers.= The best system for operating bells and annunciators from alternating current circuits is undoubtedly that employing small specially constructed transformers to reduce the voltage. These transformers are being used universally for hotel and office work where alternating current is available. They are simple, being merely one or more coils of well insulated wire wound on soft iron cores and having connections for both the lighting circuit and the bell circuit.

As a general rule the coils are divided as to their number of turns or according to the ratio of transformation desired. For example, if the circuit were 110 volts and 10 volts was required for the bell circuit, the total number of turns in the transformer would be connected, 10/11 to the lighting circuit and 1/11 to the bell circuit.

The bell-ringing transformers on the market are made in several styles. One small style, Fig. 64, for single residences, is for use on 110 volts and produces a bell voltage or secondary voltage as it is termed, of 6 volts. Another size, Fig. 65, of this transformer has three secondary voltages 6, 12 and 18, each of which can be used by connecting to the right binding posts.

It is to be noted that where the lighting service voltage or primary voltage varies from the above, the secondary voltage delivered to the bell circuit will vary in like proportion. It should also be noted that a careless reversing of the connections, that is connecting the secondary leads to the lighting circuits, instead of the primary leads would cause a like high voltage at the other terminals of the transformer, raising it in due proportion instead of lowering it. Thus such carelessness would produce a voltage of 2,400 volts instead of 6 if a transformer intended to deliver 6 volts from a 120-volt circuit was wrongly connected.

The results might very well then be dangerous. All transformers are properly marked, however, and such an error only occurs through ignorance or carelessness.

The installation of these bell-ringing transformers is simplicity itself; they require no care after installation and have met with the approval of the National Board of Fire Underwriters.

=Combination Circuits.= Circuits intended primarily for electric bells or annunciators in houses and apartments may often be also made to serve for other electrical devices such as door openers, house telephones, etc. This subsidiary apparatus may be installed with a little additional wiring or perhaps will not need any other wires, as when both the devices are not used at once.

Electrical door openers are great conveniences and are practically indispensable where the outside door is on another level to the location of the dweller or where two or more families occupy the same house. The device is simple, consisting of an electrically released spring-plate against which the lock bolt is normally held and a door opening spring.

When the door opener button is pressed, the spring plate is released, releasing the lock bolt by the same action. The door spring then forces the door open enough to clear the opener plate, which flies back into position when the button is released.

These door openers are made in several forms for door frames, such as those on thin doors, iron gates, for surface or rim locks, for thick doors, sliding doors and any other regular type of door.

The push button is the same as used for electric bells and may be located wherever desired. The pushes are wired in multiple as shown in Figs. 66 and 67, which are two circuits of a type of the Western Electric interphone, a system of house telephones supplied for houses and buildings of every size. Fig. 66 shows a circuit which provides telephone service between the vestibule and the apartments, the door opener wiring being clearly indicated. In Fig. 67 the circuit provides a more extensive service, enabling the janitor, the apartments and the tradesmen to intercommunicate in the most desirable system. The door opener wiring is also clearly shown.

The convenience of having telephone connection in the house or hotel and its advantages over speaking tubes are too well known to need extended comment. Where electric bells have already been installed it is quite feasible now to use the same wires for telephones also.

Telephone sets especially designed for this service are manufactured by the Western Electric Company in their interphone series. They are simple and compact, and may be installed by anyone who can put up an electric bell.

=Fire Alarm Circuits.= A fire alarm circuit suitable for factories, private plants or groups of buildings is shown in Fig. 68. It is a series system, with closed circuit, the gongs sounding whenever the circuit is opened whether by the contact breaker in the boxes or by the accidental breaking of a wire. This insures that it remains in good working order, as when any part of the circuit is opened, a warning tap is sounded on every bell or gong.

The boxes have contact breakers which send a separate number of impulses for each box, thus announcing the box number on each gong. The boxes and gongs may be located anywhere, as the system is perfectly flexible.

The reference letters in the diagram are as follows: _C_ indicates the gongs which are preferably of the electro-mechanical type, a coiled spring providing force for the blow, electricity being merely used to release and retain the hammer or striker. The alarm boxes are marked _BB_ and the battery which is of the closed circuit type is marked _D_.

=Interior Fire Alarm System.= Another system suitable more particularly for indoor operation is illustrated in Fig. 69. Here the alarm is given by breaking the glass front of an alarm box and releasing or pressing an electrical contact.

The box sounded indicates by causing a drop to fall on an annunciator and at the same time rings an alarm bell. The latter are generally provided with constant ring attachments, which keep the bell sounding until shut off.

The annunciator shown in the diagram has switches for controlling each individual bell circuit, and also for control of the entire system.

There is no practical limit to the number of stations in this system, it being determined by the size of the annunciator used or by other obvious factors.

The reference letters on the diagram are as follows: _A_, alarm bells which may be located wherever desired. _B_, break-glass alarm boxes also located at convenient points. _C_, annunciator drops, _D_, switches on annunciator which control each individual bell circuit, enabling any circuit to be cut out, cut in or tested without disturbing any other circuit. _E_ is a general alarm switch, causing all bells to ring at once when it is operated.

The battery _F_ varies with the number of bells and boxes and the length of line, from three cells upwards. A cut-out switch _H_ is added to cut out the entire system by opening the battery wire. The annunciator bell is at _I_, an auxiliary bell being added in multiple with it when necessary.

=Fire Alarm System for Considerable Areas.= Where the area is more extensive and the number of stations considerable, the system illustrated in Fig. 70 is very suitable. It consists of the requisite number of break-glass boxes, bells and a more elaborate annunciator system. In general details it resembles the last system, but uses a relay to send out the current for ringing the alarm bells.

When a box operates, the current impulses sent on the line act on the relay instead of directly on the bells. Each stroke of the relay closes a local circuit which includes the bells and the battery.

This system does away with large batteries and is very economical of wire. The current needed for the relay is very small, whereas in a direct system of any size, the current and voltage to ring a number of bells located at wide intervals would be prohibitive.

The reference letters are as follows: _AA_ are the alarm bells, _BB_ the break-glass alarm boxes, _C_ is the annunciator bell, _D_ is the relay which remains closed when an alarm comes in keeping the bells constantly ringing until shut off. _E_ is a resistance coil and _F_ is the battery.

A system cut-out switch _G_ and _JJ_ switches on the annunciator for controlling individual circuits are also provided. _HH_ are the annunciator drops and _K_ is a constant-ring switch which can also be used for a general alarm to ring all the bells at once.

LEARN TO DO THINGS

Model Library Series

OF COPYRIGHTED BOOKS

1. The Study of Electricity for Beginners.

2. Dry Batteries, How to Make them.

* 3. Electrical Circuits and Diagrams, Part 1.

4. Electric Bells, Annunciators and Alarms.

5. Modern Primary Batteries.

6. Experimenting with Induction Coils.

* 7. Electric Gas Igniting Apparatus.

* 8. Small Accumulators, How to Make and Use.

9. Model Steam Engine Design.

* 10. Practical Electrics.

11. Inventions, How to Protect and Sell them.

12. Woodwork Joints, How to Make and Use.

* 13. The Fireman’s Guide to the Care of Boilers.

* 14. The Slide Valve Simply Explained.

* 15. The Magneto Telephone.

* 16. The Corliss Engine and Its Management.

* 17. Making Wireless Outfits.

18. Wireless Telephone Construction.

* 19. The Wimshurst Machine, How to Make It.

20. Simple Experiments in Static Electricity.

21. Small Electrical Measuring Instruments.

22. Electrical Circuits and Diagrams, Part 2.

* 23. Induction Coils, How to Make Them.

24. Model Vaudeville Theatres.

* 25. Alternating Currents, Simply Explained.

* 26. How to Build a 20 foot Bi-plane Glider.

* 27. A B C of the Steam Engine.

* 28. Simple Soldering, Hard and Soft.

* 29. Telegraphy for Beginners.

30. Low Voltage Lighting with Storage Batteries.

33. House Wiring for Electric Light.

34. Magnets and Magnetism.

* 36. Small Windmills and How to Make Them.

Injectors, Their Construction and Use. Keppy.

Refrigeration and Ice Making. Wakeman.

37. Collin’s Wireless Plans, Part 1.

38. Collin’s Wireless Plans, Part 2.

In paper covers Price 25c each postpaid.

*These books can also be had in cloth binding at 55c each postpaid.

Dubelle’s Famous Formulas.

KNOWN AS

Non Plus Ultra Soda Fountain Requisites of Modern Times

By G. H. DUBELLE.

_A practical Receipt Book for Druggists, Chemists, Confectioners and Venders of Soda Water._

SYNOPSIS OF CONTENTS.

INTRODUCTION.--Notes on natural fruit juices and improved methods for their preparation. Selecting the fruit. Washing and pressing the fruit. Treating the juice. Natural fruit syrups and mode of preparation. Simple or stock syrups.

FORMULAS.

FRUIT SYRUPS.--Blackberry, black current, black raspberry, catawba, cherry, concord grape, cranberry, lime, peach, pineapple, plum, quince, raspberry, red current, red orange, scuppernong grape, strawberry, wild grape. NEW IMPROVED ARTIFICIAL FRUIT SYRUPS--Apple, apricot, banana, bitter orange, blackberry, black current, cherry, citron, curacoa, grape, groseille, lemon, lime, mandarin, mulberry, nectarine, peach, pear, pineapple, plum, quince, raspberry, red current, strawberry, sweet orange, tangerine, vanilla. FANCY SODA FOUNTAIN SYRUPS.--Ambrosia, capillaire, coca-kina, coca vanilla, coca-vino, excelsior, imperial, kola coca, kola-kina, kola-vanilla, kola-vino, nectar, noyean, orgeat, sherbet, syrup of roses, syrup of violets. ARTIFICIAL FRUIT ESSENCES.--Apple, apricot, banana, bergamot, blackberry, black cherry, black currant, blueberry, citron, cranberry, gooseberry, grape, lemon, lime fruit, melon, nectarine, orange, peach, pear, pineapple, plum, quince, raspberry, red currant, strawberry. CONCENTRATED FRUIT PHOSPHATES. Acid solution of phosphate, strawberry, tangerine, wild cherry.--29 different formulas. NEW MALT PHOSPHATES--36. FOREIGN AND DOMESTIC WINE PHOSPHATES--9. CREAM-FRUIT LACTARTS--28. SOLUBLE FLAVORING EXTRACTS AND ESSENCES--14. NEW MODERN PUNCHES--18. MILK PUNCHES--17. FRUIT PUNCHES--32. FRUIT MEADS--18. NEW FRUIT CHAMPAGNES--17. NEW EGG PHOSPHATES--14. FRUIT JUICE SHAKES--24. EGG PHOSPHATE SHAKES. HOT EGG PHOSPHATE SHAKES. WINE BITTER SHAKES--12. SOLUBLE WINE BITTERS EXTRACTS--12. NEW ITALIAN LEMONADES--18. ICE CREAM SODAS--39. NON-POISONOUS COLORS. FOAM PREPARATIONS. MISCELLANEOUS FORMULAS--26. LATEST NOVELTIES IN SODA FOUNTAIN MIXTURES--7. TONICS.--Beef, iron and cinchona; hypophosphite; beef and coca; beef, wine and iron; beef, wine, iron and cinchona; coca and calisaya. LACTARTS.--Imperial tea; mocha coffee; nectar; Persian sherbert. PUNCHES. EXTRACTS.--Columbia root beer; ginger tonic; soluble hop ale. LEMONADES.--French; Vienna. Egg nogg. Hop ale. Hot tom. Malt wine. Sherry cobbler. Saratoga milk shake. Pancretin and wine. Kola-coco cordial. Iron malt phosphate. Pepsin, wine and iron, etc.

157 Pages, Nearly 500 Formulas. 12mo., Cloth, $1.00

A NEW AMERICAN BOOK ON INDUSTRIAL ALCOHOL.

A PRACTICAL HANDBOOK ON THE

Distillation of Alcohol

FROM FARM PRODUCTS AND

DE-NATURING ALCOHOL.

By F. B. WRIGHT.

Including the Free Alcohol Law and its Amendment, the Government regulations therefore and a number of U. S. government authorized de-naturing formulas.

In the preparation of this, the second edition, the author has followed his original plan of writing a plain practical handbook on the manufacture of alcohol and de-naturing for industrial purposes. This industry is bound to grow to enormous proportions as it has in Germany where over 100,000,000 gallons were manufactured last year principally in small farm distilleries. This work is not intended as a scientific treatise but as a help to farmers and others wishing to go into this industry on a moderate scale.

The original matter has been carefully revised. Some of the chapters rewritten and a very considerable amount of new information added. The total number of illustrations brought up to 60 including a number of plates giving the layout of distilleries.

Contents of Chapters.

1, Alcohol, its various forms and sources. 2, The preparation of mashes and Fermentation. 3, Simple Distilling Apparatus. 4, Modern Distilling Apparatus. 5, Rectification. 6, Malting. 7, Alcohol from Potatoes. 8, Alcohol from Grain, Corn, Wheat, Rice and other Cereals. 9, Alcohol from Beets. 10, Alcohol from Molasses and Sugar Cane. 11, Alcoholometry. 12, Distilling Plants. Their general arrangement and equipment. 13, De-natured Alcohol and U. S. Authorized De-naturing Formulae. 14, De-naturing Regulations in the United States. Index.

281 pages, 60 illustrations and plates, 12mo., cloth, $1.00.

Send for this to-day

Fourth Edition, Enlarged

REVISED AND REWRITTEN

ELECTRICAL TESTING

BY NORMAN H. SCHNEIDER

Contents of Chapters.

1. and 2. Galvanometers. 3. Rheostats, keys and shunts. 4. Voltmeters and ammeters. 5. The Wheatstone bridge. 6. Portable testing sets. 7. Testing with the galvanometer. 8. The Potentiometer. 9. Condensers. 10. Cable testing. 11. Testing with the voltmeter. 12. Testing telephone lines. 13. Testing telegraph wires and cables. 14. Locating faults in telegraph and telephone cables.

Tables; Index; with numerous practical illustrations worked out.

314 pages, 150 illustrations, cloth $1.15 postpaid.

Spon & Chamberlain, 123-5 LIBERTY STREET, NEW YORK

Transcriber’s Notes

Punctuation and spelling were made consistent when a predominant preference was found in this book; otherwise they were not changed.

Simple typographical errors were corrected.

Occurrences of inconsistent hyphenation have not been changed.