The enclosure has been manufactured using transparent plastic panels,
glued together with a plastic glue. When ready, the enclosure has been
covered with silver color paint. The rear panel is detachable to enable
the pulling out of the circuit board. It was
kept transparent and small holes has been drilled in it.
This is for enabling the frequency adjustment and measuring the battery voltage from outside, without
disassembling the clock.
-front panel potentiometer for brightness adjustment
-the clock speed does not depends on power grid frequency. There is an
internal quartz crystal driven oscillator
-possibility for accurate adjustment of the clock speed (by adjusting the oscillator frequency)
-powered from mains power supply with low power consumption: 1.42 VA
-the backup battery is in operation only when mains power supply is not
available, therefore it last for long time (years)
-after about 30 years of continuous use it still works just fine
-making modifications to LED modules and connections to watch PCB
without damaging the components, require
a good soldering iron, accuracy and attention in work
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The author has made the best efforts to ensure the design and the information provided are reliable.
Under no circumstances shall the author be liable for any direct, indirect, incidental, special
or consequential loss, damage, expense or injury incurred or suffered which is claimed
to resulted from use of this site, even if expressly advised of the possibility of
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including, without limitation, any fault, error, omission, interruption or delay with respect thereto.
 - RCL Semiconductors Limited - manufacturer of digital watches ICs
 - LM339 - quad comparator