Points North Ltd.

Marine Gyro Compass / Navigational & Communication Systems   Marine Electrical & Electronic Systems

48  STEP  PER  DEGREE   RETRANSMISSION  UNIT -  948

New gyro compasses are normally supplied with a 24 volt supply so they keep running if power is lost. The 948 is intended to be fed from the same DC source, so it too can keep operating. If the new gyro supply does not have enough power it obviously 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 948 provides high voltage to rotate the repeaters, then it gives a low (rms) voltage to hold position at a low current. This is done by program control, with the EPROM being selected for an optimum, but not critical, setting at installation time.

SPECIFICATION

INPUT:              NMEA 0183. All valid heading sentences. 4800 baud.

One or two decimal places (or more) are accepted.

If there are two decimal places the motors are rotated in a smoother way than with one.

OUTPUT:          Drive for 2 pole stepper motors.   Maximum current 8 Amps total.

24 volts DC for illumination.

6 pin connector.

Rotation (follow-up) rate. 5 or 10 degrees per second. Adjustable by jumper.

The output rate, and current, can be adjusted by changing locations in the EPROM.

The smoothness of the rotation depends on the precision of the input data.

ALARM RELAY: Low power single pole change over relay to switch an independent

                        external audible and visual alarm, which is not supplied.

POWER:           24 volts DC at 0.2 to 6 Amps depending on load.

Auto reset fuse on removal of power.

CONNECTIONS: Pluggable terminal blocks.

ENCLOSURE:   300 mm wide x 400 mm high x 150 mm deep

Duck egg blue electrical enclosure with door.