Scope Clock


One day my father asked me if I wanted his old Heatkit 10-10 oscilloscope. Quickly I said "No. What can I do with this old AC-only 500khz single trace scope?" A couple of weeks later I was surfing the net and I saw some guy who had made a clock with the CRT like my father's scope. I grabbed the phone to ask him if he still had the scope … and the answer was yes.

That was the first time I had to work with a CRT. I have learned lots of things such as 1500 volts is "hard on your finger". If you take a look at the schematic you will see that I found a way to generate lots of different voltages for the CRT which needs different voltages for astigmatism, focus, blanking and other controls. Another thing I learned is your DC voltage must be very clean; on 1500 volts you cannot have 10 volts of ripple, and also the tube is very sensitive to external magnetic fields. I have used an opto-coupler for the interface between my MCU blanking output and the -1500 to -1400 volt. And to make it easy to tune I used an IR remote control to setup the time, date and the internal setup of the firmware.



  • Very special look
  • Remote control setting
  • Time & Date display



Clock Schematic

Source Code

5 Comments to “Scope Clock”

  • April 23, 2010 at 8:54 am

    congratulation! i have a question about 1200vac circuit. how can you generate 1200vac.
    thank you.

  • admin April 23, 2010 at 12:48 pm

    Hmmm, I don’t have any credit for that, I had use the original transformer that was in the old scope… The way you can try it’s to build a switching powersupply but don’t ask me how I don’t have any knowleage in that. You also can try with a 110Vac to 220Vac transformer and with diode make a doubler, tripler voltage. Keep me inform on your way you take


  • Wordpress Themes June 13, 2010 at 7:41 am

    Good dispatch and this enter helped me alot in my college assignement. Thank you on your information.

  • Robert October 28, 2011 at 2:33 pm

    Very nice job!  Interesting how you generate the images using digital potentiometer.  I am designing similar device and must study your code further to understand how you accomplished this.

  • Sirajul July 18, 2012 at 3:01 pm

    Hi great project! Surprised to see so few feedback! 
    What about screen burning, you need to write a screensaver – but screensaver for a clock is paradoxical isn't it :)

    To about HVT:

    I made 3500 volt transformer by my own. Just take a oversize core with large window area. Large core will give you smaller t/v and wind the secondary in layer with proper paper and end gap each layer. You can also use TV flybacks but that needs redesigning the drive circuit. 

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Please note

All my source codes were taken from my personal projects.

Everything is for your information only. The C/C++ codes have been written
with ICCAVR. You can find the header and source CRT files by downloading their compiler.

All is for your information and everything is AS IS without any warranty of any kind. No other files are available and I don't make any modification for any body.



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