Features and advantages of Schauer master clocks and central units with impulse-controlled slave clocks
Why use a master clock with slave clocks?
Here, there are several advantages:
1. User friendliness
The daylight savings changeover has to be individually carried out with every quartz and synchronous clock. Think about the amount of work and time (e.g. use of ladder, access to rooms/space) it takes until all clocks are set to the correct time. This invariably occurs automatically using a master clock. With DCF-controlled quartz battery clocks, the question always arises whether there is adequate reception at the intended site.
The accuracy of stand-alone clocks with a 230V connection depends on network frequency; with battery-operated quartz movements +/- 0.4 seconds per day. This means deviations of up to several minutes over a longer period of time, and the clocks don’t run synchronously. Imagine a double-sided clock that shows different times on each side. A master clock without an external synchronous unit has an accuracy of at least +/- 0.1 seconds per day. With a DCF or GPS antenna, which in an extreme case can be mounted 100 meters away, absolute coordination with the standard time can be achieved. The central impulse control also ensures the simultaneous change of minutes of all slave clocks.
The durability of slave clock units is many times greater than with synchronous or quartz clock systems. We know of a few cases, such as the sacristy clock of St. Stephen’s cathedral in Vienna, or several train station clocks, which have used slave clock systems since the beginning of the 1950s.
4. Temperature fluctuations
Use of quartz and synchronous clock systems is limited to indoors. Outdoor clocks mainly only run with slave clock systems.
5. Clock size flexibility
With a hand length of 20cm, quartz clock systems have a very limited application. Synchronous clock systems use a hand length of up to 30cm. Slave clockwork systems have a length of up to 50cm. For larger and/or exposed hands, motor motion works are used.
6. Made in Austria
Schauer master clocks are a unique Austrian product (maintenance, replacement of spare parts, quick repair, Austria-wide service).
When do I use a clock central?
Central clock units are used to divide the clock network into clear units and to increase operational reliability. In principle, every so-called line module is a master clock with a slave clock connection that is coordinated and controlled by a central master clock. Depending on requirements – whether for an airport, a hospital, theatre, fire department and so on – various modules are combined.
What wiring networks are necessary?
In normal cases the master clock needs to be connected to a 230VAC. Upon request we offer special constructions with a DC supply. Slave clocks with mere impulse drive – analogue and LCD digital clocks – are connected to the master clock parallel with the 24VDC impulse line. LED digital clocks, illuminated clocks, sport clocks, time/temperature displays or similar need a 230VAC connection in addition to the impulse line.
Do You have Questions?
Ing. Erich Blaschka
+43 1 61055-216