I actually start off with a 3.6V 1/2AA battery, the higher the input voltage, the lower the currents will be. This will reduce some of the losses in the 'HV switcher'. I know that most 1/2AA batteries cannot supply the required current, but a few can and it's a good choice as they are smaller than a CR2. Of course that is not the whole story, the circuit itself is quite complex as I couldn't find a single IC that would do the same job.
Apart from that, I added a daylight sensor and will PWM the tubes according to the amount of daylight. I used the same circuit in another design with LEDs. Believe it or not, but I went from 5mA in bright daylight down to 50uA (40dB difference) in pure darkness, always keeping the LEDs on a constant contrast compared to the amount of ambient light. I don't expect to get 40dB out of the nixie tubes, but I think 20dB can be achieved. This would bring the current down from 200mA in bright daylight to 20mA at night, keeping the display always readable. Even 40mA would be good enough as this will already significantly improve the efficiency of the HV circuit. The processor will be put into deep sleep mode between readings (drawing about 1uA) and wake-up either by a soft touch button or an IR motion sensor. Not sure if I can fit the IR motion sensor on the final design, but I try my best. So all together, it will be very low power. Best regards, Michel On Jan 30, 5:08 pm, threeneurons <threeneur...@yahoo.com> wrote: > On Jan 29, 9:09 pm, Cobra007 <mic...@xiac.com> wrote: > > > Well, I probably started on the wrong foot in this group and yeah, you > > can't take back the things you post so I am sorry for that. I agree > > that I should have done more research and this would not have > > happened. > > Welcome to the group. Don't sweat it. We all get a little overly > enthusiastic sometimes. > > As for your watch concepts, the big hurdles are packaging and power. > Coding a uC is really a non-issue. Its really arranging the tubes, > batteries, and the few components, in as small of a 3D space as > possible, with the tube still showing the digits. I'm really curious > about your HV power supply. I'm assuming you're going to use 3V. There > are uCs that can work down to 1.8V, as well as 5V. That same 3V can > power the uC directly, and pump the HV switcher. To get most of the > battery life, I imaging the switcher will still lite the tubes down at > 1.8V in, and do it with reasonable efficiency. So far only Jeff & > David have done it. If it was easy, everybody would do it. > > Please share your progress. This is after all a hobby group, and we > are on this web (still think its only a passing fad). I give high > brownie points to those who share their ideas. All the info on my > nixie projects, are free for anyone to make, given they actually want > to. Just Google threeneurons nixie. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
