<s>
A	O
flux	B-Algorithm
switching	I-Algorithm
alternator	I-Algorithm
is	O
a	O
form	O
of	O
high-speed	O
alternator	B-Algorithm
,	O
an	O
AC	O
electrical	O
generator	O
,	O
intended	O
for	O
direct	O
drive	O
by	O
a	O
turbine	O
.	O
</s>
<s>
This	O
is	O
needed	O
to	O
power	O
the	O
guidance	O
and	O
fuzing	B-Protocol
systems	O
,	O
possibly	O
also	O
the	O
high-power	O
loads	O
of	O
an	O
active	O
radar	O
seeker	O
(	O
i.e.	O
</s>
<s>
Control	O
surface	O
actuators	B-Algorithm
for	O
a	O
high-speed	O
missile	O
require	O
a	O
high	O
force	O
and	O
so	O
these	O
are	O
usually	O
powered	O
by	O
some	O
non-electric	O
means	O
,	O
such	O
as	O
tapping	O
propellant	O
exhaust	O
gas	O
from	O
the	O
missile	O
's	O
motor	O
.	O
</s>
<s>
Depending	O
on	O
the	O
missile	O
type	O
,	O
it	O
may	O
also	O
be	O
required	O
to	O
start	O
delivering	O
power	O
almost	O
immediately	O
after	O
start-up	O
,	O
or	O
even	O
before	O
launch	O
to	O
allow	O
gyroscopes	B-Application
to	O
be	O
accelerated	O
to	O
speed	O
,	O
and	O
to	O
provide	O
power	O
for	O
varying	O
lengths	O
of	O
time	O
.	O
</s>
<s>
The	O
batteries	O
used	O
are	O
usually	O
esoteric	O
types	O
rarely	O
found	O
outside	O
missiles	O
,	O
such	O
as	O
silver-zinc	B-Algorithm
or	O
thermal	B-Architecture
batteries	I-Architecture
.	O
</s>
<s>
Although	O
the	O
power	O
requirement	O
for	O
the	O
missile	O
may	O
be	O
a	O
largely	O
DC	O
supply	O
,	O
the	O
AC	O
alternator	B-Algorithm
and	O
its	O
need	O
for	O
a	O
rectifier	B-Algorithm
is	O
still	O
favoured	O
for	O
its	O
mechanical	O
robustness	O
.	O
</s>
<s>
Early	O
AC	O
systems	O
used	O
the	O
standard	O
frequency	O
of	O
400Hz	O
,	O
which	O
limited	O
alternators	B-Algorithm
to	O
two	O
pole	O
rotors	O
and	O
a	O
maximum	O
rotation	O
speed	O
of	O
24,000	O
rpm	O
.	O
</s>
<s>
The	O
Seaslug	O
missile	O
alternator	B-Algorithm
used	O
a	O
speed	O
of	O
24,000	O
rpm	O
to	O
produce	O
1.5kVA	O
of	O
electricity	O
at	O
2,400	O
Hz	O
.	O
</s>
<s>
This	O
gas	O
may	O
also	O
be	O
used	O
to	O
power	O
the	O
control	O
surface	O
actuators	B-Algorithm
,	O
as	O
was	O
used	O
for	O
Vigilant	O
.	O
</s>
<s>
Ability	O
to	O
start	O
the	O
gas	O
generator	O
before	O
launching	O
,	O
allowing	O
time	O
for	O
gyroscopes	B-Application
to	O
be	O
spun	O
up	O
to	O
speed	O
,	O
power	O
for	O
control	O
surfaces	O
etc	O
.	O
</s>
<s>
The	O
first	O
alternators	B-Algorithm
of	O
this	O
type	O
began	O
with	O
the	O
first	O
missiles	O
requiring	O
considerable	O
electric	O
power	O
,	O
those	O
using	O
radar	O
seekers	O
(	O
initially	O
semi-active	O
radar	O
homing	O
)	O
.	O
</s>
<s>
By	O
the	O
late	O
1950s	O
,	O
turbine-driven	O
alternators	B-Algorithm
were	O
also	O
being	O
used	O
in	O
lightweight	O
anti-tank	O
missiles	O
such	O
as	O
Vigilant	O
.	O
</s>
<s>
The	O
alternator	B-Algorithm
and	O
turbine	O
were	O
fitted	O
into	O
a	O
remaining	O
annular	O
space	O
of	O
only	O
1inches	O
.	O
</s>
<s>
An	O
alternative	O
high-speed	O
generator	O
is	O
the	O
permanent	O
magnet	O
magneto	B-Algorithm
.	O
</s>
