(and other cool homemade stuff...)
On the rare occasions I've got nothing better to do, I like building large and/or
unusual digital clocks. Please note that I cannot provide detailed schematics, PCB
layouts etc. for these designs - they are intended to give ideas or inspiration to other
potential clock-builders, but feel free to email with any specific queries. See also the Nixie Clock page.
Huge countdown clock display built for iPhone launch at three UK O2 stores - more pics here
Custom nixie display built for countdown
equences in the UK TV production How not to get on Big Brother (Endemol). April 2002 (To be shown on Channel 4,
Mon 20th May 22:00)
This uses ten 74HC595 shift /latch registers and 80 MMBTA42 driver
transistors, as it was done in a hurry and I had to use components which could be obtained
and assembled quickly - with more notice I'd probably have used a couple of the Supertex shiftreg/HV driver chips to
minimise component count
Huge nixie clock using Burroughs B7971 alphanumeric tubes (2000)
The PCB forms the top of the case, with glued acrylic frame and bottom ABS cover. NE-2 bulb inside plastic tube used as flashing hour/minute seperator.
Details showing tube sockets formed from 'D'
connector socket contacts, with rings cut from PVC pipe, glued to PCB as surrounds.
Probably the smallest nixie clock in the world (well it was at the time - Jeff Thomas's nixie watch just beats it).... (2000).
After getting hold of some tiny nixie tubes, I decided it would be fun to build a nixie car-clock....
Overall size is 80 x 25 x 45mm, case made from glued ABS sheet.
is mostly surface-mount, on three stacked PCBs.
Rear of front PCB, showing HV driver
Rear power supply board, containing 5V
regulator for PIC, and switchmode converter to generate 200V
supply for the nixies. Time-setting buttons on right.
Clock built with some
old light-guide filament displays, based on a modified
version of my nixie clock PCB.
Large clock using Electroluminescent (EL) display, 4.5" high digits (2000). This
display is made up from EL strips (originally intended for display backlights in pagers),
which give a very nice uniform cool blue-green glow, unlike any LED. They are only about
1.5mm thick, and the whole clock case, made from glued acrylic sheet, is only an inch
thick. The EL strips require a high-voltage (200V) AC drive - this supply comes from a
standard Pacel EL inverter module. The Inverter chosen is significantly over-rated (it's
designed to drive A4 Sheet size panels), to avoid the display brightness varying too much
when different numbers of segments are lit. The high-voltage inverter output is switched
to the segments using MOC3020 type triac optoisolators, driven by a PIC processor.
Small dot-matrix clock (~1994). Uses eight 5x7 matrix displays to
form a 10 x 28 dot matrix, of which only 8 x 28 are used. Controlled by PIC processor,
with HC595 shift-registers as column drivers. Display is proportionally-spaced, and
self-centres depending on the width of displayed digits. The hour/minute seperator is a
bar which gives an hourglass-type effect, gradually 'filling up' throughout each minute
and 'emptying' when the minute rolls over.
Second Large clock (1991). Uses 4" high LED displays - the biggest available at the time. Colon is two HP half-inch square bar modules. Driven by a standard 5387-type clock chip, with external ULN2003 drivers. Slim handmade case - consisting of a glued outer frame in 6mm black acrylic, with rear panel glued on, and front window screwed into tapped holes in frame. Single large 16 x 5.5" PCB (etched with the aid of driptray from Mum's refrigerator!), with components surface-mounted on rear. Powered by external mains transformer. To avoid the need for unsightly switches, time-setting is done by bringing a magnet near one of two reed-switches.