The Bozeman courier. (Bozeman, Mont.) 1919-1954, 1923-08-15

MECHANICAL relay Aoapkapte 70 I
BY John =. 5ront
Some interesting results have been
obtained with a relay built In a similar
way to the q described and sketched
here. The mechanical working prin-
c1ple Of the apparatus is not q new one,
yet is uniquely applied in the recording
OF received radio time signals by isOlat-
Ing them In q local circuit In which is
included a recorder. C~uriously enough
the instrument is applicable to record
Ing OF continuous wave signals, more
so than to those Of d~ecsying trains.
In detail we may examine what takes
place when a straight steel wire has
either or both of its ends thrust to-
ward each other. A very slight move
ment Of the ends toward each other is
followed by the wire bowling Outwardly
In the center and forming an arc. The
closer b wire is to Its normal shape
the greater will he the movement of
the center Of the wire outwardly from
its normal position. when pressure Is
applied at either or both ends in q
direction along the original normal
axis Of the wire, for a given move
ment Of the ends toward each other.
The slight movement Of the ends to-
ward each other. in fact, is magniAed
In the resultant movement or bending
out Of the center AS the ends are
moved nearer each other, the resultant
outward movement Of the center por-
ton grows less. If a curve we're
drawn, It would show a steep portion
at the beginning and gradually round.
ing of toward the point represented
where the ends of the wire are sup
posed to be parallel with each other
in the bending process. That Is when
the wire is bent double.
Construction Of Relay.
In the relay sketched here the steel
wire is fastened to the diaphragm of
a large-sized receiving phone. At the
center where the greatest movement
takes place for a given thrust on either
end, is placed a contact which Is in
cluded in a local circuit, as is a portion
of the steel wire itself. The opposite
end of the wire is securely held rigid.
The contact below the center of the
wire is adjusted by a micrOmeter ar
rangement which requires a large
movement of the adjusting screw for q
slight change in the height of the con.
tact. which is made of spring brass
and securely fastened at one end. while
the lower emo is drilled to pass the
screw of the adjusting arrangement
and fits against the adjusting nut.
Operation.
In, operation. the attraction Of the
diaphragm at each wave train makes
a change in the position of the center
of the wire and If the micrometer ap
paratus is adjusted correctly a loca
circuit will be opened and closed a
each movement Of the diaphragm. Els
pecially where continuous waves arr
being dealt with, this type Of rela,
Is most efficient, and II Is necessar,
only to rectify the received trains
without going through the operation
Of h~eterodyning. Each arriving trail
will cause attraction and release tn
diaphragm, which movement is com
municated to the steel wire.
The wire Is not maintained at It
exactly straight horizontal position
but slightly bowed down In the cente
to facilitate the action Of a permanen
magnet placed Immediately below tn
wire so as to insure the me cement O
the center Of the wire downward an
not to n side or upward when tn
t movement of the diaphragm Ia com
municated to 1t, through the action o
: the rectihed trains Of continuou
waves.
The whole apparatus is IN fact a
r ampIlier and relay at the same tim,
although 1t has been made up for r,
laying only. The diaphragm movement
is amplifed In the movement Of til
center Of the wire, which movement
the agency in closing and opening
r local circuit. Experiments were mad
which reversed the usual order Z
things and arranged for the breakin
i. of a local circuit which would operal
. o recorder instead of the usual tyE
which-is made to close q local Circuit
Batteries.
Primary batteries were connected
q series with the recorder and one er