Sgitheach Scope Clock II Derivate - 3RP1A

This is an early version of a CRT tube clock, based on the "Scope Clock II" design by Sgitheach.

http://sgitheach.org.uk/scope2.html

My design uses the TubeTime.us CRT driver boards, to drive the CRT tube, the circle generator circuit and the software part is from Sgitheach.

You can find the TubeTime.us boards here, on the original website.

http://tubetime.us/?p=183

Since I don't have anything better at the moment, I'm using a crap chinese SMPS to power the filament.
It's set to 6.3V and 600mA. It oscillates a lot in the ramp up phase, but it becomes perfectly stable when reaching the required voltage.

It seems like I have a blanking amplifier bandwidth issue, that's what causes the unwanted traces. This issue will be addressed later.

As explained at some point in this video, the original circle generator has been slightly modified to only use one single +12V suppy.
This supply is then converted into +5V using a simple linear regulator IC, LM7805CV.
The +5V is then fed into a charge pump IC, Linear LTC1983, to generate the negative rail voltage of -5V.
Most of the analog ICs are then powered by +12V/-5V, except the DAC, and the multiplexer, which are powered by +5V/-5V.

Since some voltages differs from the original design, I had to add some trimpots to adjust the DAC voltage references manually.
I also shifted the output higher, to comply with the TubeTime.us deflection board requirements. This boards needs 0 to +5V, centered on +2.5V for X and Y deflection, and for the video signal.

There are also some other websites that inspired me, and motivated me for this, and other designs.

http://oscilloclock.com/
http://www.cathodecorner.com/index.html
http://www.labguysworld.com/LabguysProjects.htm
http://gjlay.de/pub/morpheus/index.html

Thank you for sharing your knowledge to the world. Keep up the good work!

To be continued...

Видео Sgitheach Scope Clock II Derivate - 3RP1A канала Etienne