WESTERSTRAND
Document: 1853en08.doc
Author: Tan/CF
Date: 2013-09-05
Page: 2 of 7
WESTERSTRAND URFABRIK AB
P.O. Box 133
Tel. +46 506 48000
Internet:: http://www.westerstrand.se
SE-545 23 TÖREBODA
Fax. +46 506 48051
E-mail:
General
Westerstrand analogue clock is constructed to meet the high demands required in an outside environment.
Special care has been taken to achieve reliability, availability and maintainability.
The housing is built up with a aluminium housing combining strength and light weight.
The Platform Clock is an analogue clock with sweeping hour hand, stepping minute hand and sweeping second
hand if there is one.
Round outdoor clocks with diameter 400 mm, 600 mm. and 900mm.
Console mounted single, double sided clocks or single sided wall mounted clocks.
The clock is equipped with control electronics for reception of time code from a GPS receiver and controlling
the movements.
The clock movements, which are connected to the electronics via RJ45 connectors, do not contain any electronic
except for the hand sensors.
The GPS receiver is designed for outdoor installation.
Functional description control electronics and movement
Start up
When the power is connected to the electronics, the hands will step forward to 12-position. When a GPS time
signal is received and accepted the hands will step forward to correct time.
If not the hands will wait in 12-position.
Failure GPS time code
If the GPS time signal is lost, or faulty, the control electronics will keep the clock running using the internal
quartz crystal as time reference. After 12-hours of lost signal the hands will rapid impulse to 12-position, stop
there, and wait for a valid signal.
Power failure
During a power failure the minute and hour hand will stop. When power is back the hands will step forward to
12-position. When a GPS time signal is received and accepted the hands will step forward to correct time.
If not the hands will wait in 12-position.
Control of hand position
The position of the minute hand is checked once every hour at minute 00. If correct time and the position of the
shaft do not correspond the hand is corrected by stopping or stepping the hand.
The electronics check the position of the hour hand once every 12-hour.
If the clock has Seconds, the location is checked once every minute
