- on Home & Garden
- Published in issue 2/2009 on page 42
Quartz clock with a trinary display
Inspired by a binary clock he saw at a mathematics museum the author of this design went one step further and came up with a more mathematically challenging timepiece...
This unusual large format digital clock in the photo shows the time in binary and is exhibited at the German Museum of Mathematics ‘Mathematikum’ in the town of Giessen, Germany. The museum is the brainchild of Prof. Beutelsbacher and has been described as the fi rst ‘hands-on’ mathematical museum in the world.
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CAM/CAD data for the PCB referred to in this article is available as a Gerber file. Elektor Members can exclusively download these files for free as part of their Membership. Gerber files allow a PCB to be produced on an appropriate device available locally, or through an online PCB manufacturing service. Elektor recommends its business partner Eurocircuits as the company of choice for its own prototypes and volume production in selected cases.
R1-R8 = 220 ?
R9-R26 = 1k?8
R27-R37 = 100k?
R38 = 4M?7
R39 = 270k?
C1 = 27pF
C2 = 100pF
C3 = 100?F 25V radial
C4-C15 = 100nF
D1-D8 = bicolour LED, red/green, common cathode (e.g. Conrad Electronics 185000)
D9- D22 = 1N4148
T1-T18 = BC547B
IC1-IC9 = 4017
IC10 = 4060
IC11 = 4081
IC12 = 4013
JP1,JP2 = 3-way SIL pinheader with jumper, or miniature changeover switch
X1 = 32.768kHz quartz crystal
7 wire links
PCB, ref. 060030-1 from www.thepcbshop.com