Specifications

13
COMPASS
FOR COMNAV FLUX-GATE COMPASS
!
The compass
MUST
be mounted
as close as practical to the vessels
centre of pitch and roll.
This is typically
low in the vessel, at about the waterline,
and slightly aft of the centre of the
vessel.
!
You must keep the compass at
least three feet away from engines,
electric motors, and other magnetic
objects. If this is not possible, their
effects may be compensated for as
described in the SEA TRIALS section of
this manual.
!
To reduce or eliminate the effect
of the vessels vertical field, a HEELING
ADJUST control is provided on the
ComNav Fluxgate Compass, (although
the sensitivity to the earth’s vertical
magnetic field remains.)
!
Because of the sensitivity of the
fluxgate compass to the earth's vertical
magnetic fields, it is
NOT
recommended
for use at latitudes higher than 50
degrees (North or South).
!
Use the HEELING ADJUST
control on the compass to eliminate the
effect of the vessel's vertical magnetic
field as described in the SEA TRIALS
section of this manual. The HEELING
ADJUST control is turned OFF when it is
in the centre of its travel.
!
Plug the end of the cable into the
compass receptacle on the rear of the
autopilot. If the length of cable supplied
with the compass is not adequate, obtain
an extra plug-in length from your dealer.
Cutting and splicing the compass cable is
NOT
recommended.
FOR OTHER FLUXGATE COMPASSES
!
The autopilot can be used with a
Fluxgate Compass which outputs DC
Sine and Cosine signals of up to +/- 3
volts amplitude about a 0 to 6 VDC
reference.
!
If the compass does not have a
HEELING ADJUST control (i.e. other
makes of fluxgate compasses), it should
NOT
be used on steel vessels either.
!
The interface has been tested
with Fluxgate Compasses manufactured
by KVH, Brookes and Gatehouse, and
VDO. Some of these compasses have to
be specially ordered in order to have the
required DC Sine and Cosine outputs.
!
The autopilot has been supplied
with a 10 ft cable which is plugged into
the Compass receptacle on the rear of
the autopilot. The other end of the cable
is terminated in flying leads.
See 0 for
colour & function of each lead
.
!
+12 Volts will appear on the wire
connected to Plug Pin 7 when the
autopilot is turned on. Up to 100
milliamps can be supplied by this wire to
power the fluxgate compass.
!
If the compass is separately
powered, the tinned ends should be cut
off of the wires connected to Plug Pins 7
& 4. The wires should then be taped
back against the cable to prevent
accidentally shorting out the +12V power
supply inside the autopilot.
Any other unused wires should also have
their tinned leads cut off and be taped
back against the cable.