Vermes
Advanced Member level 4
The first edition was built on a cardboard with many cables (the first picture).
The clock has no additional options like a timer, it's built just to look good on table.
There is only a battery sustain against outage, biping on every full hour and, of course, the blue highlight switch on twilight. Additionally, an automatic adjust of the numbers light was designed (on LM337). Therefore, the clock looks good in clear at day and at night.
All used chips are CMOS. The frequency generator 1/60 Hz combines a 4060 system stabilized with a quartz resistor with 4520 and one logical gate. The proper time counting is made by 4026, and the resetting is made by logical gates. The time is set by two switches. Using three potentiometers, the backlight of the display, the threshold of switching on the blue light and it's intensity can be adjusted. The whole power supply is made on 12-18V DC. The current consumption depended on the lightened modules is in range from 30mA to 180mA.
The battery backup is made on two CR2032 batteries and it allows the clock to work for about 70 hours. To save power, all the high consumption options are switched off. Only the time is viewed.
The whole housing was made from a transparent 3mm Plexiglass. It was bended using HOT-Air and glued using the same Plexiglass with some nitro solvent. The whole housing is lightened by 4 blue 3mm LEDs.
The clock was designed in Dip Trace, made by thermo-transfer method.
Link to original thread (jpg schema attachment) – CMOS-owy zegar w obudowie z pleksy