“The PC board holds a switching power supply, a crystal-controlled microcontroller
for generating the timing and scanning the digits, and an analog circle generator
system to draw the digits. It makes circles directly from sine and cosine waves.
That’s why the curves look so clean.
The drawing of the digits is done in segments, each segment being composed of an arc,
circle or line. Angled lines are made by putting the same cosine wave onto both
the X and Y deflection plates.
The display repetition rate is synchronized to the power line frequency by the
microprocessor to prevent image ’swimming’ in the presence of strong AC fields.
This allows the CRT to be free of magnetic shielding, which would add to the cost
and detract from the beauty of the clock.”
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November 1st, 2006
I tried contacting David Forbes regarding the release of his latest version of the Scope Clock (I was interested in purchasing one), but have not received a reply to date.
Do you have any suggestions or information?
Thanks in advance.
March 27th, 2007
build those and sell them!! i would buy them!
May 24th, 2007
Though not completely self contained like David Forbes’ clock, the AVR Oscilloscope from Dutchtronix (www.dutchtronix.com/ScopeClock.htm) gives you a very nice looking clock on a CRT, just add an old analog scope with X/Y mode. Because it can run from both the on board Real Time Clock, or from an external 1 Pulse Per Second signal (think GPS module), it can run very accurately.
Control is through a serial port and the clock can be quite fun to play with; it even has a DEMO mode!