Hello David, Humm, what time difference do we have? seems like they're up in Tucson around the same time as here in NSW!
I did in fact take all of that into account, that's why I mentioned I'd be happy to get 14dB dimming out of it (20 - 6) The battery can be purchased through element14 or newark as you call it in USA and only costs a few bucks. If you only need to replace it every 2 years or so, I don't think that will be an issue for anyone. Best regards, Michel On Jan 30, 6:49 pm, David Forbes <[email protected]> wrote: > On 1/30/12 12:06 AM, Cobra007 wrote: > > > 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. > > It is nice to use a battery that can be purchased locally. The CR2 is > available worldwide. The 1/2AA is a special item. Customers don't like > to have to special-order a battery on short notice. > > > > > 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. > > One thing about Nixie tubes that you may not be aware of is that they > need some time to start firing, because the plasma is triggered by an > external source of energy such as a photon from the room lighting or a > stray cosmic ray. The less ambient light there is, the more time they > need to start. If you reduce the duty cycle in the dark, you may find > that the display doesn't start reliably. > > This is why some Nixie tubes were made with radioactive krypton in the > tube. But not the 5870 series, as they were designed to be used in an > office environment. > > I would suggest experimenting with this dimming idea before committing > to it. You would hate to discover later that your watch display is > unreliable. > > It may be possible to solve this problem by detecting when the current > starts to flow in the tube, and leave the tube powered up until the > current starts, then begin the PWM operation. > -- > David Forbes, Tucson AZ -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
