Numitron desktop clock - Using only classical components
Do you know "Numitrons"?Those incandescent 7 segments bulbs are used here to make a 6 digits clock with a very nice orange glow: I used "IV-9" russian tubes that are cheap and easy to get on eBay (look for "IV-9 numitron").
Do you know "Numitrons"?
Those incandescent 7 segments bulbs are used here to make a 6 digits clock with a very nice orange glow: I used "IV-9" russian tubes that are cheap and easy to get on eBay (look for "IV-9 numitron").
Brightness control is included and this clock uses only 12 volts, so no risk with high voltage here (you can put your fingers, these tubes are NOT Nixies).
This 6 digits Numitron clock is built with only classical components that are very easy to find (16F887 PIC processor, UNL 2003 & UNL 2803, DS 1302 timechip, 7 transistors and 48 1N4148 diodes).
Everything fits on a 16 x 10 cm double-sided PCB, ready to be simply screwed on a wooden block to make a great desktop clock with all components visible (see photos)!
Project status:
- PCB finalised - Very nice with buttons and status leds aligned - Note that 1 IC has not been used on prototype, will de suppressed in final PCB release
- Clock /calendar software (written in C) is finalized, including bright control, time/date setup, ECO mode, battery test (CR2032)
- An automatic DCF synchronization is planned (connector available) but software is not done for this final part.
- I also plan to add an LDR for automatic brightness control, will have space on new PCB version
- I already built six for last Xmas owners looked happy ;-)
Vote for my project and you build yours for Chrismas!
Discussie (2 opmerking(en))
Larry# 4 jaar geleden
Jean-Marc Buhler 4 jaar geleden
I found that multiplexing Numitrons is quite easy in fact (using diodes yes), the only drawback is that you need to increase the voltage to compensate for the brightness lost; I used 12V for 4v5 numitrons, but of course one need to take care of timings or you would end end burning (very) quickly your tubes if the multiplexing stopped on one filament for too long. I used around 1 KHZ for multiplexing on this working project and even added some pauses to better dim the display. Also, multiplexing helps keeping the total power down, as driving the six tubes in parallel is quite power hungry.
FYI, I am now working on a new version based on CD4017 for the practical multiplexing and Raspberry Pico for the CPU ; the idea would be to use the 2 hearts, one for the display and the other one for DCF77 decoding...
Stay tuned ;-)
Jean-Marc.
Larry# 4 jaar geleden
Armin Hennecke 11 jaar geleden
Your clock looks very good! I like it because I found some Minitrons operating similar to Numitrons. I wanted to build a clock, too.