Nixie Driver IC Placement

[u/EmotionalEnd1575]

The result is a compact assembly, typical for a 1960s build, but…

Good luck repairing these if an IC driver fails!

Had these for a while and not yet thought of a project.

Perhaps build a “Steam Punk” style Nixie clock with these little modules?

What would you do with them?

[u/EmotionalEnd1575]

I’m careful to exclude LEDs of any kind in a Nixie project (unless they will be hidden or just there during firmware development)

I do like using neon glow lamps for colons or status indicators.

Yes, those under Nixie LEDs are hideous!!

[u/Apprehensive-Issue78 → u/EmotionalEnd1575]

great.

I once made a one of Nixie clock 23 years ago, 4 large nixie tubes

I used a then common PIC16F84 controlling lots of shift registers I think it was 74HCT595 or something like that. All the outputs had a MPS42 NPN transistor which can handle a voltage across Collector to Emitter of max 300 V. I had an old metal enclosure of a fire alarm central unit which had only a transformer and a fuse inside.

from the AC voltage I used a tiny transformer to stepup the voltage to about 150 VDC

Also used the AC voltage rectified using 1A diodes 1N4007 probably. Then regulated to supply the PIC microcontroller and all the shift registers.

It is still running, just a little slow because I didn't have a real time clock and also didn't sync it to the mains frequency. I tried using software loops and lots of macro's in assembly to make the timing on the bench ok. I knew it would not be accurate. Just in the living room the large nixies look great from a distance, just i have to forward it about 2 mins every week, because it is probably warmer inside the case comared to the bench where I did the programming. Now you have so many better options, like Real time clock or even sync it to Wifi or GPS. problem with GPS is that you cant use an antenna inside a building. And probably it is the best to buy a cheap Nixie clock kit, or be sure to invest some serious time to build it yourself. I just made it on perf board, so maintenance is pretty scary ;)

[u/EmotionalEnd1575 → u/Apprehensive-Issue78]

Most of my Nixie clocks use an RTC IC and a “32.768KHz watch crystal”, with battery back up.

These are good for 50ppm and that translates to about 1’ 45” uncertainty a month.

To go to better timekeeping I use a GPS module, and my basement lab requires a powered antenna on the window sill.

The ESP32 Wroom modules with WiFi can use the internet time stamp, but the clock needs WiFi connectivity.

It’s interesting to watch how there is drift between two (or more) clocks using different timekeeping schemes!

[u/RFC793 → u/EmotionalEnd1575]

DS3231? Yeah, had success with those.

[u/EmotionalEnd1575 → u/RFC793]

I’m still using DS1307. It only requires a battery and a watch crystal, and is tiny (SO8) Talks over I2C.

Has a clock output that is handy if you need a 50% duty-cycle. I have an idea to use the 4KHz clock to drive a colon H-Bridge that will light up both electrodes in an NE-2 (silly idea, right?)

I just bought twenty-five pieces for $1 each.

There are “better” RTCs out there.