The Electrical experimenter
The Electrical experimenter
The Electrical experimenter
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May, 19 1<br />
NOVEL TELEGRAPH INSTRU-<br />
MENT THAT RESPONDS TO<br />
VOICE.<br />
Strange as the title may seem, yet the<br />
successful operation of such a device has<br />
been accomplislied thru the researches of<br />
Mr. Christian Berger of New Vork City.<br />
<strong>The</strong> accompanyintr phutograpli shows the<br />
complete equipment of the electric voiceoperated<br />
telegraph instrument. <strong>The</strong> operation<br />
of the device is not attained by the<br />
employment of a microphone of any kind,<br />
but by means of a sensitive sound-operated<br />
circuit-breaker, which controls a special<br />
relay and wliich in turn operates electrically<br />
either a sounder or recording instrument.<br />
<strong>The</strong> circuit-I)rcaker is placed in<br />
a metal bo.x which is seen in the center<br />
background of the photograph. This consists<br />
of a bent wire, properly balanced on<br />
an insulating block. <strong>The</strong> end of this wire<br />
presses lightly against the side of the bo.x,<br />
which makes a permanent contact when it<br />
is not disturbed. <strong>The</strong> second connection<br />
is made thru tlie metal box and this is terminated<br />
with one binding post of a battery,<br />
while the bent wire is connected to one<br />
side of the relay electro-magnet, the opposite<br />
side being linked to the other binding<br />
post of the battery. <strong>The</strong> electro-magnet<br />
actuates an armature which controls<br />
a cog-wheel by means of a projecting strip<br />
on the armature. On the same shaft with<br />
the cog-wheel is a drum upon which a<br />
number of contacts are secured. <strong>The</strong>se are<br />
alternately connected, so that one will complete<br />
the electrical circuit when desired<br />
and when moved to the next stud, the circuit<br />
will be opened. It is built on tlie lines<br />
of a step-by-step relay, which has been<br />
used some years ago for controlling moving<br />
vessels by radio waves. <strong>The</strong> drum circuit<br />
and the horizontal brushes which touch<br />
the drum studs, are connected in series<br />
with the recording instrument and battery.<br />
<strong>The</strong> operation of the apparatus is exceedingly<br />
simple as one must only be familiar<br />
with the telegraph code, but not<br />
experienced in handling a telegraph key,<br />
as the transmitting is done by calling out<br />
the dot and dashes to the instrument.<br />
When a signal is made the sensitive sound<br />
actuated circuit-breaker opens the circuit<br />
which causes the armature of the relay to<br />
release it, thus giving a rotary motion to<br />
the cogwheel and in turn closing the recording<br />
instrument circuit. <strong>The</strong> complete<br />
equipment is very interesting when in action<br />
and possesses many diversified possi-<br />
bilities.<br />
THE ELECTRICAL EXPERIMENTER •7<br />
LOS ANGELES HAS WONDERFUL<br />
ELECTRIC FIRE TRUCK.<br />
electric THEtire-fighting equipment of a new<br />
apparatus recently<br />
built by the I-os Angeles fire<br />
partment has no equal in<br />
de-<br />
the<br />
country.<br />
mounted on a ton<br />
This equipment is<br />
and a half motor truck<br />
As a precaution against any one accidentally<br />
touching the foot throttle and speeding<br />
up the engine to too great a speed, when<br />
the wagon is standing at a fire, a special<br />
protective device has been provided, which<br />
consists of a hood which can be lowered<br />
and locked in a position, completely protecting<br />
the foot throttle from the curious.<br />
Los Angeles, Cal., Boasts of Having One of the Most Complete Electric Fire-fighting Trucks<br />
in the United States. <strong>The</strong> Equipment Comprises Five Powerful Searchlights Which Are<br />
Supplied with Power from Either a Large Storage Battery or the Dynamo Shown in the<br />
Picture.<br />
and was both designed and built by members<br />
of the fire department.<br />
<strong>The</strong> equipment consists of five powerful<br />
searchlights, each rated at 250 watts, capable<br />
of throwing a brilliant beam of light<br />
over 500 feet avvay. .At this distance work<br />
at a fire can be carried on with great efficiency.<br />
Vet these lights are so arranged<br />
with diflfusing lenses that it does not blind<br />
the firemen, even a few feet away.<br />
<strong>The</strong> lights are 16 inches in diameter.<br />
Three are permanent and<br />
two are portable, each being<br />
attached to 320 feet of<br />
heavily insulated cable<br />
wound on a reel which can<br />
be unrolled, permitting the<br />
lights to be carried this<br />
distance<br />
building.<br />
into a burning<br />
<strong>The</strong> handicap of a strange<br />
and smoky building is overcome<br />
by the use of these<br />
portable lights. <strong>The</strong>y will<br />
penetrate smoke to almost<br />
an unliclievable distance,<br />
Speak to This Telegraphic Novelty and It Reco ds the<br />
alent Dots and Dashes on a Paper T ape.Equlv-<br />
permitting the firemen to<br />
fight fires thru dense smoke<br />
with the greatest of ease.<br />
I'ower is received from eight large stor-<br />
ICELAND'S ELECTRICAL PAPER.<br />
r.h'ktron is the name of an electrical<br />
magazine publisht monthly at Reykjavik,<br />
Iceland. <strong>The</strong> leading article is on the Icelandic<br />
telegraphs and telephones, by Mr.<br />
Oisli J. Olafscn, who visited this country<br />
a year or more ago and studied .Xmcrican<br />
age batteries placed behind the seat. <strong>The</strong>se<br />
batteries themselves are capable of furnishing<br />
current for the lights for seven hours.<br />
Also installed on the right foot-board is<br />
a generator of SO amperes, 25 volts. 1.25<br />
K.W. This is run by a silent chain drive<br />
off the main propeller shaft and is controlled<br />
by a separate clutch, shown in front<br />
telegr.Tph and telephone methods. This article<br />
is printed in the Danish and English<br />
of the switchboard seen in the photo. <strong>The</strong><br />
generator may be cut in or out at will, by<br />
languages.<br />
means of this clutch.<br />
-A perfectly equipt switchboard is mounted<br />
on the right side immediately above the<br />
generator, having a marble back in an enclosed<br />
case with a glass front. It is equipt<br />
with a master switch for both the batteries<br />
and generators. Also an individual<br />
switch for each light and gages to show<br />
amperes and volts, a resistance cut-out and<br />
small lights to illuminate the board. Fuses<br />
of proper capacity are installed for each<br />
switch. To prevent damage to generator or<br />
batteries an under-load and an over-load<br />
switch is installed. This acts as a governor,<br />
the purpose of which is to automatically<br />
disenga.ge the charging line from the<br />
generator when the rate of charge reaches<br />
a dangerous value or when the rate of<br />
charge is so low that there would be danger<br />
of the batteries bleeding.<br />
<strong>The</strong> portable lights are adapted to be<br />
used on a tripod. <strong>The</strong>y are mounted on<br />
the wagon on a swivel connection with a<br />
one-inch diameter stem projecting, which<br />
fits into a socket fastened with a nut.<br />
A similar socket is provided on the tripod<br />
and when the light is set on the tripod, a<br />
large hand nut is provided which holds it<br />
securely. <strong>The</strong> light mounted on the tripod<br />
can be readily moved from place to place<br />
by one man. .As he carries the light to<br />
he fire the reel automaticallv unwinds.<br />
A wireless telegraph distance record of<br />
11,500 miles was establisht by the steamer<br />
Sonoma, which pickt up messages from Eilvese,<br />
Germany, when two days oflf .Australia,<br />
according to Royden Thomberg and<br />
Clio Bowers, operators on the Sonoma.<br />
Ellery Stone, assistant United States radio<br />
inspector at San Francisco, said it was<br />
the greatest distance achievement in wireless<br />
telegraphy.