23 Dec
2007
23 Dec
'07
2:46 a.m.
On Dec 22, 2007, at 12:38 PM, Tom Peters wrote:
Here's the schematic:
http://www.neurotica.com/misc/step-up-regulator.png
I'll see about writing up some better docs for it later. The
values of the timing capacitor (C3) and the gate pulldown resistor
(R4) could probably use some optimization; I've not done much tuning
there. It works well as-is though; I've powered four IN-17 tubes
with it at 100% duty cycle with no heating or other issues.
The power inductor (L2) needs to be able to handle the current,
and have low DC resistance and good core saturation
characteristics...I used a Murata 2200R series unit, Mouser part
number 580-22R334C.
The MOSFET, fast-recovery diode, and low-ESR capacitors are
readily available in small lots via eBay, very cheaply.
I generate
the 170VDC for Nixie (and similar) applications from
12VDC using an MC34063-based step-up switching regulator, the design
of which is based on a circuit from one of the chip's app notes. I
can send you the schematic if that'd be helpful.
Please send schematic, thanks. 
Who makes the MC34063? Something I could get at
DigiKey or Mouser?
Yes, Mouser stocks them. It's originally a Motorola design, but
it has been second-sourced by lots of companies. The ones I have on
hand here are from STMicro, and were purchased from Mouser.
I did some reading last year and I read something
about driving
Nixies with DC, is that what's usually done, rather than AC?
Yes, Nixie tubes are usually driven with DC.
-Dave
--
Dave McGuire
Port Charlotte, FL
Farewell Ophelia, 9/22/1991 - 7/25/2007