How to Install Electric Bells, Annunciators, and Alarms. Including Batteries, Wires and Wiring, Circuits, Pushes, Bells, Burglar Alarms, High and Low Water Alarms, Fire Alarms, Thermostats, Annunciators, and the Location and Remedying of Troubles

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 sho...

=The Wire.= The size of the copper wire used in bell work is No. 16, or No. 18, B and S gauge, and sometimes smaller, such as No. 20 to 22. But smaller wire than No. 18 has too...

Polarized, or magneto, bells are used in telephone work, and are rarely operated by a battery, but have a miniature dynamo generator operated by hand, or power, to supply the ac...

The degree in which different substances expand varies for the same increase in temperature. This fact is used in a common form of thermostat shown in Fig. 38. A strip of wood o...

The Leclanche battery cell is shown in Fig. 2, where _J_ is a glass jar, _Z_ a rod of zinc, and _P_ a jar of porous earthenware containing a carbon rod surrounded by powdered ca...

=The Annunciator.= The mechanism of an annunciator consists of electromagnets which allow shutters to drop or needles to move on the circuits being closed. A bell is also rung i...

Three-wire return call system--Installing elevator annunciators--Burglar alarm annunciators--Clock alarm circuit--Bells for high voltages--Bell-ringing transformers--Combination...