<s>
In	O
engineering	O
,	O
a	O
solenoid	B-Algorithm
is	O
a	O
device	O
that	O
converts	O
electrical	O
energy	O
to	O
mechanical	O
energy	O
,	O
using	O
an	O
electromagnet	B-Algorithm
formed	I-Algorithm
from	I-Algorithm
a	I-Algorithm
coil	I-Algorithm
of	I-Algorithm
wire	I-Algorithm
.	O
</s>
<s>
In	O
electromagnetic	O
technology	O
,	O
a	O
solenoid	B-Algorithm
is	O
an	O
actuator	B-Algorithm
assembly	O
with	O
a	O
sliding	O
ferromagnetic	O
plunger	O
inside	O
the	O
coil	O
.	O
</s>
<s>
Electromagnets	O
with	O
fixed	O
cores	O
are	O
not	O
considered	O
solenoids	B-Algorithm
.	O
</s>
<s>
In	O
simple	O
terms	O
,	O
a	O
solenoid	B-Algorithm
converts	O
electrical	O
energy	O
into	O
mechanical	O
work	O
.	O
</s>
<s>
In	O
engineering	O
,	O
the	O
term	O
may	O
also	O
refer	O
to	O
a	O
variety	O
of	O
transducer	B-Algorithm
devices	O
that	O
convert	O
energy	O
into	O
linear	O
motion	O
,	O
more	O
sophisticated	O
than	O
simple	O
two	O
–	O
position	O
actuators	B-Algorithm
.	O
</s>
<s>
The	O
term	O
"	O
solenoid	B-Algorithm
"	O
also	O
often	O
refers	O
to	O
a	O
solenoid	B-Algorithm
valve	O
,	O
an	O
integrated	O
device	O
containing	O
an	O
electromechanical	O
solenoid	B-Algorithm
which	O
actuates	B-Algorithm
either	O
a	O
pneumatic	O
or	O
hydraulic	O
valve	O
,	O
or	O
a	O
solenoid	B-Algorithm
switch	O
,	O
which	O
is	O
a	O
specific	O
type	O
of	O
relay	O
that	O
internally	O
uses	O
an	O
electromechanical	O
solenoid	B-Algorithm
to	O
operate	O
an	O
electrical	O
switch	O
;	O
for	O
example	O
,	O
an	O
automobile	B-Algorithm
starter	I-Algorithm
solenoid	I-Algorithm
or	O
linear	O
solenoid	B-Algorithm
.	O
</s>
<s>
Solenoid	B-Algorithm
bolts	O
,	O
a	O
type	O
of	O
electromechanical	O
locking	O
mechanism	O
,	O
also	O
exist	O
.	O
</s>
<s>
Electromechanical	O
solenoids	B-Algorithm
consist	O
of	O
an	O
electromagnetically	O
inductive	O
coil	O
,	O
wound	O
around	O
a	O
movable	O
steel	O
or	O
iron	O
slug	O
(	O
termed	O
the	O
armature	O
)	O
.	O
</s>
<s>
The	O
movement	O
of	O
the	O
armature	O
is	O
used	O
to	O
provide	O
a	O
mechanical	O
force	O
to	O
some	O
mechanism	O
,	O
such	O
as	O
controlling	O
a	O
solenoid	B-Algorithm
valve	O
.	O
</s>
<s>
Although	O
typically	O
weak	O
over	O
anything	O
but	O
very	O
short	O
distances	O
,	O
solenoids	B-Algorithm
may	O
be	O
controlled	O
directly	O
by	O
a	O
controller	O
circuit	O
,	O
and	O
thus	O
have	O
very	O
quick	O
reaction	O
times	O
.	O
</s>
<s>
Electromechanical	O
solenoids	B-Algorithm
are	O
commonly	O
seen	O
in	O
electronic	O
paintball	O
markers	O
,	O
pinball	O
machines	O
,	O
dot	O
matrix	O
printers	O
,	O
and	O
fuel	O
injectors	O
.	O
</s>
<s>
Some	O
residential	O
doorbells	O
make	O
use	O
of	O
electromechanical	O
solenoids	B-Algorithm
,	O
whereby	O
electrification	O
of	O
the	O
coil	O
causes	O
the	O
armature	O
to	O
strike	O
metal	O
chime	O
bars	O
.	O
</s>
<s>
Push	O
and	O
pull	O
solenoids	B-Algorithm
are	O
common	O
catalog	O
items	O
,	O
usually	O
in	O
a	O
tubular	O
construction	O
.	O
</s>
<s>
Each	O
type	O
is	O
similar	O
to	O
the	O
other	O
in	O
construction	O
except	O
that	O
the	O
pull	O
type	O
has	O
means	O
for	O
attaching	O
to	O
the	O
plunger	O
and	O
pulls	O
the	O
attached	O
load	O
toward	O
the	O
solenoid	B-Algorithm
.	O
</s>
<s>
The	O
push	O
type	O
has	O
a	O
push-pin	O
projecting	O
out	O
of	O
the	O
solenoid	B-Algorithm
to	O
push	O
the	O
load	O
away	O
from	O
the	O
solenoid	B-Algorithm
.	O
</s>
<s>
Most	O
solenoids	B-Algorithm
do	O
not	O
use	O
magnetic	O
repulsion	O
between	O
the	O
magnetic	O
pole	O
and	O
plunger	O
to	O
do	O
the	O
pushing	O
except	O
in	O
rare	O
instances	O
.	O
</s>
<s>
Common	O
push	O
or	O
pull	O
solenoids	B-Algorithm
move	O
in	O
one	O
direction	O
only	O
upon	O
being	O
energized	O
.	O
</s>
<s>
Included	O
in	O
this	O
category	O
of	O
solenoids	B-Algorithm
are	O
the	O
uniquely	O
designed	O
magnetic	O
circuits	O
that	O
effect	O
analog	O
positioning	O
of	O
the	O
solenoid	B-Algorithm
plunger	O
or	O
armature	O
as	O
a	O
function	O
of	O
coil	O
current	O
.	O
</s>
<s>
These	O
solenoids	B-Algorithm
,	O
whether	O
axial	O
or	O
rotary	O
,	O
employ	O
a	O
flux	O
carrying	O
geometry	O
that	O
both	O
produces	O
a	O
high	O
starting	O
force	O
(	O
torque	O
)	O
,	O
and	O
has	O
a	O
section	O
that	O
quickly	O
begins	O
to	O
saturate	O
magnetically	O
.	O
</s>
<s>
The	O
resulting	O
force	O
(	O
torque	O
)	O
profile	O
as	O
the	O
solenoid	B-Algorithm
progresses	O
through	O
its	O
operational	O
stroke	O
is	O
nearly	O
flat	O
or	O
descends	O
from	O
a	O
high	O
to	O
a	O
lower	O
value	O
.	O
</s>
<s>
The	O
solenoid	B-Algorithm
can	O
be	O
useful	O
for	O
positioning	O
,	O
stopping	O
mid-stroke	O
,	O
or	O
for	O
low	O
velocity	O
actuation	O
;	O
especially	O
in	O
a	O
closed	O
loop	O
control	O
system	O
.	O
</s>
<s>
A	O
uni-directional	O
solenoid	B-Algorithm
would	O
actuate	O
against	O
an	O
opposing	O
force	O
or	O
a	O
dual	O
solenoid	B-Algorithm
system	O
would	O
be	O
self	O
cycling	O
.	O
</s>
<s>
Focusing	O
of	O
the	O
magnetic	O
field	O
and	O
its	O
attendant	O
flux	O
metering	O
,	O
as	O
illustrated	O
in	O
the	O
SAE	O
paper	O
,	O
is	O
required	O
to	O
produce	O
a	O
high	O
starting	O
force	O
at	O
the	O
start	O
of	O
the	O
solenoid	B-Algorithm
stroke	O
and	O
to	O
maintain	O
a	O
level	O
or	O
declining	O
force	O
as	O
the	O
solenoid	B-Algorithm
moves	O
through	O
its	O
displacement	O
range	O
.	O
</s>
<s>
This	O
is	O
quite	O
contrary	O
to	O
that	O
experienced	O
with	O
normal	O
diminishing	O
air	O
gap	O
types	O
of	O
solenoids	B-Algorithm
.	O
</s>
<s>
Further	O
incrementing	O
of	O
the	O
plunger	O
causes	O
a	O
continuing	O
decrease	O
of	O
the	O
solenoid	B-Algorithm
force	O
thus	O
creating	O
an	O
ideal	O
condition	O
for	O
motion	O
control	O
as	O
controlled	O
by	O
the	O
current	O
to	O
the	O
solenoid	B-Algorithm
coil	I-Algorithm
.	O
</s>
<s>
An	O
opposing	O
spring	O
force	O
or	O
a	O
dual	O
ended	O
solenoid	B-Algorithm
(	O
two	O
coils	O
)	O
allows	O
over	O
and	O
back	O
motion	O
control	O
.	O
</s>
<s>
The	O
rotary	O
solenoid	B-Algorithm
is	O
an	O
electromechanical	O
device	O
used	O
to	O
rotate	O
a	O
ratcheting	O
mechanism	O
when	O
power	O
is	O
applied	O
.	O
</s>
<s>
Repeated	O
actuation	O
of	O
the	O
rotary	O
solenoid	B-Algorithm
advances	O
the	O
snap-switch	O
forward	O
one	O
position	O
.	O
</s>
<s>
Two	O
rotary	B-Algorithm
actuators	I-Algorithm
on	O
opposite	O
ends	O
of	O
the	O
rotary	O
snap-switch	O
shaft	O
,	O
can	O
advance	O
or	O
reverse	O
the	O
switch	O
position	O
.	O
</s>
<s>
The	O
rotary	O
solenoid	B-Algorithm
has	O
a	O
similar	O
appearance	O
to	O
a	O
linear	O
solenoid	B-Algorithm
,	O
except	O
that	O
the	O
armature	O
core	O
is	O
mounted	O
in	O
the	O
center	O
of	O
a	O
large	O
flat	O
disk	B-Device
,	O
with	O
three	O
inclined	O
raceways	O
coined	O
into	O
the	O
underside	O
of	O
the	O
disk	B-Device
.	O
</s>
<s>
These	O
grooves	O
align	O
with	O
raceways	O
on	O
the	O
solenoid	B-Algorithm
body	O
,	O
separated	O
by	O
ball	O
bearings	O
in	O
the	O
races	O
.	O
</s>
<s>
When	O
the	O
solenoid	B-Algorithm
is	O
activated	O
,	O
the	O
armature	O
core	O
is	O
magnetically	O
attracted	O
toward	O
the	O
stator	O
pole	O
,	O
and	O
the	O
disk	B-Device
rotates	O
on	O
the	O
ball	O
bearings	O
in	O
the	O
races	O
as	O
it	O
moves	O
towards	O
the	O
coil	O
body	O
.	O
</s>
<s>
When	O
power	O
is	O
removed	O
,	O
a	O
spring	O
on	O
the	O
disk	B-Device
rotates	O
it	O
back	O
to	O
its	O
starting	O
position	O
both	O
rotationally	O
and	O
axially	O
.	O
</s>
<s>
The	O
rotary	O
solenoid	B-Algorithm
was	O
invented	O
in	O
1944	O
by	O
George	O
H	O
.	O
Leland	O
,	O
of	O
Dayton	O
,	O
Ohio	O
,	O
to	O
provide	O
a	O
more	O
reliable	O
and	O
shock/vibration	O
tolerant	O
release	O
mechanism	O
for	O
air-dropped	O
bombs	O
.	O
</s>
<s>
Previously	O
used	O
linear	O
(	O
axial	O
)	O
solenoids	B-Algorithm
were	O
prone	O
to	O
inadvertent	O
releases	O
.	O
</s>
<s>
Leland	O
's	O
engineer	O
,	O
Earl	O
W	O
.	O
Kerman	O
,	O
was	O
instrumental	O
in	O
developing	O
a	O
compatible	O
bomb	O
release	O
shackle	O
that	O
incorporated	O
the	O
rotary	O
solenoid	B-Algorithm
.	O
</s>
<s>
It	O
was	O
a	O
1-inch	O
diameter	O
version	O
of	O
the	O
Leland	O
solenoid	B-Algorithm
that	O
served	O
as	O
the	O
camera	O
shutter	O
for	O
Mariner-4	O
'	O
s	O
fly-by	O
of	O
Mars	O
in	O
July	O
1965	O
.	O
</s>
<s>
Solenoids	B-Algorithm
of	O
this	O
variety	O
continue	O
to	O
be	O
used	O
in	O
countless	O
modern	O
applications	O
and	O
are	O
still	O
manufactured	O
under	O
Leland	O
's	O
original	O
brand	O
"	O
Ledex	O
"	O
,	O
now	O
owned	O
by	O
Johnson	O
Electric	O
.	O
</s>
<s>
Appearing	O
on	O
the	O
market	O
in	O
the	O
1980s	O
,	O
the	O
solely	O
rotary	O
solenoid	B-Algorithm
with	O
a	O
balanced	O
3-lobed	O
iron	O
vane	O
rotor	O
offered	O
improved	O
vibration	O
isolation	O
by	O
eliminating	O
the	O
axial	O
motion	O
of	O
the	O
rotor	O
.	O
</s>
<s>
A	O
rotary	O
voice	B-Device
coil	I-Device
is	O
a	O
rotational	O
version	O
of	O
a	O
solenoid	B-Algorithm
.	O
</s>
<s>
Rotary	O
voice	B-Device
coils	I-Device
are	O
widely	O
employed	O
in	O
devices	O
such	O
as	O
disk	B-Device
drives	I-Device
.	O
</s>
<s>
The	O
working	O
part	O
of	O
a	O
moving	O
coil	O
meter	O
is	O
also	O
a	O
type	O
of	O
rotary	O
voice	B-Device
coil	I-Device
that	O
pivots	O
around	O
the	O
pointer	O
axis	O
,	O
a	O
hairspring	O
is	O
usually	O
used	O
to	O
provide	O
a	O
weak	O
nearly	O
linear	O
restoring	O
force	O
.	O
</s>
<s>
A	O
pneumatic	O
solenoid	B-Algorithm
valve	O
is	O
a	O
switch	O
for	O
routing	O
air	O
to	O
any	O
pneumatic	O
device	O
,	O
usually	O
an	O
actuator	B-Algorithm
,	O
allowing	O
a	O
relatively	O
small	O
signal	O
to	O
control	O
a	O
large	O
device	O
.	O
</s>
<s>
Hydraulic	O
solenoid	B-Algorithm
valves	O
are	O
in	O
general	O
similar	O
to	O
pneumatic	O
solenoid	B-Algorithm
valves	O
except	O
that	O
they	O
control	O
the	O
flow	O
of	O
hydraulic	O
fluid	O
(	O
oil	O
)	O
,	O
often	O
at	O
around	O
3000	O
psi	O
(	O
210	O
bar	O
,	O
21	O
MPa	O
,	O
21	O
MN/m2	O
)	O
.	O
</s>
<s>
Hydraulic	O
machinery	O
uses	O
solenoids	B-Algorithm
to	O
control	O
the	O
flow	O
of	O
oil	O
to	O
rams	O
or	O
actuators	B-Algorithm
.	O
</s>
<s>
Solenoid-controlled	O
valves	O
are	O
often	O
used	O
in	O
irrigation	O
systems	O
,	O
where	O
a	O
relatively	O
weak	O
solenoid	B-Algorithm
opens	O
and	O
closes	O
a	O
small	O
pilot	O
valve	O
,	O
which	O
in	O
turn	O
activates	O
the	O
main	O
valve	O
by	O
applying	O
fluid	O
pressure	O
to	O
a	O
piston	O
or	O
diaphragm	O
that	O
is	O
mechanically	O
coupled	O
to	O
the	O
main	O
valve	O
.	O
</s>
<s>
Solenoids	B-Algorithm
are	O
also	O
in	O
everyday	O
household	O
items	O
such	O
as	O
washing	O
machines	O
to	O
control	O
the	O
flow	O
and	O
amount	O
of	O
water	O
into	O
the	O
drum	O
.	O
</s>
<s>
Transmission	O
solenoids	B-Algorithm
control	O
fluid	O
flow	O
through	O
an	O
automatic	O
transmission	O
and	O
are	O
typically	O
installed	O
in	O
the	O
transmission	O
valve	O
body	O
.	O
</s>
<s>
In	O
a	O
car	O
or	O
truck	O
,	O
the	O
starter	B-Algorithm
solenoid	I-Algorithm
is	O
part	O
of	O
an	O
automobile	O
engine	O
's	O
ignition	O
system	O
.	O
</s>
<s>
The	O
starter	B-Algorithm
solenoid	I-Algorithm
receives	O
a	O
large	O
electric	O
current	O
from	O
the	O
car	B-Algorithm
battery	I-Algorithm
and	O
a	O
small	O
electric	O
current	O
from	O
the	O
ignition	O
switch	O
.	O
</s>
<s>
when	O
the	O
key	O
is	O
turned	O
to	O
start	O
the	O
car	O
)	O
,	O
the	O
small	O
electric	O
current	O
forces	O
the	O
starter	B-Algorithm
solenoid	I-Algorithm
to	O
close	O
a	O
pair	O
of	O
heavy	O
contacts	O
,	O
thus	O
relaying	O
the	O
large	O
electric	O
current	O
to	O
the	O
starter	O
motor	O
.	O
</s>
<s>
Starter	B-Algorithm
solenoids	I-Algorithm
can	O
also	O
be	O
built	O
into	O
the	O
starter	O
itself	O
,	O
often	O
visible	O
on	O
the	O
outside	O
of	O
the	O
starter	O
.	O
</s>
<s>
If	O
a	O
starter	B-Algorithm
solenoid	I-Algorithm
receives	O
insufficient	O
power	O
from	O
the	O
battery	O
,	O
it	O
will	O
fail	O
to	O
start	O
the	O
motor	O
and	O
may	O
produce	O
a	O
rapid	O
,	O
distinctive	O
"	O
clicking	O
"	O
or	O
"	O
clacking	O
"	O
sound	O
.	O
</s>
<s>
Any	O
of	O
these	O
will	O
result	O
in	O
some	O
power	O
to	O
the	O
solenoid	B-Algorithm
,	O
but	O
not	O
enough	O
to	O
hold	O
the	O
heavy	O
contacts	O
closed	O
,	O
so	O
the	O
starter	O
motor	O
itself	O
never	O
spins	O
,	O
and	O
the	O
engine	O
fails	O
to	O
start	O
.	O
</s>
