48 STEP PER DEGREE
RETRANSMISSION UNIT
KW948
INTRODUCTION
The KW948 may be used in a refit when a new
gyro replaces the old one, which had 48 step
per degree repeaters.
This includes certain C Plath, Anschutz, and
other gyros. The repeaters are those that use a
24 volt DC motor supply, with standard
industrial stepper motors having two isolated
windings.
New gyro compasses are normally supplied with
a 24 volt supply so they keep operating if power
is lost. The KW948 uses the same DC source,
so it too can keep operating. If the new gyro
supply does not have enough power it needs an
additional power source.
Typical repeaters take no more than 0.8 amps
per step, but the power required is less than expected from a simple ohms law calculation. The KW948
outputs the full voltage to rotate the repeaters, then, when in position it gives a rectangular pulse train to hold
position at a low current.
SPECIFICATION
INPUT: NMEA 0183. All valid heading sentences. 4800 baud.
One or more decimal places are accepted.
OUTPUT: 6 pin lift-off connector block. 24 volts DC for illumination.
Drive for 2 pole stepper motors, with two separate windings.
Maximum current 6 Amps total, hold current approximately 0.5 amps.
A version for 96 steps per degree is available.
Rotation (follow-up) rate. 5 or 10 degrees per second. Adjustable by jumper.
With an input of two decimal places the motors will naturally rotate in a smoother way than
with one decimal place, 100 steps rather than 10.
ALARM RELAY: Low power single pole change over relay to switch an independent external alarm
POWER: 24 volts DC at 0.2 to 6 Amps depending on load. Resettable fuse.
CONNECTIONS: Pluggable terminal blocks.
ENCLOSURE: 25 cm wide x 35 cm high x 15 cm deep
Grey electrical enclosure with door, for bulkhead mounting.
ENCAPSULATION: Certain parts are normally encapsulated to prevent copying. This means it is not
possible to change the EPROM or replace the output driver chips.
AMI - GFV MARINE Ltd. Southampton, UK
TEL 44 (0) 23 8048 0450 FAX 44 (0) 23 8048 0451/2
