Reversing the diode would be a bad idea as the current will have nowhere to go once the HV switch opens. What you could do is take an ordinary AC transformer (say 240V primary 12V secondary), go from AC to DC using a rectifier bridge and capacitor, then feed your 555-based HV circuit out of this DC voltage. Then connect the +300V to the GND of your circuit and you have a -300V where normally the GND would be. Just be sure not to power anything else out of this secondary winding.
Michel On Dec 19, 10:56 am, Joseph Bento <[email protected]> wrote: > Jonathan, > > I'm going to hold off a bit on selling them. The more I look at the clock > on the decadecounter web site, the closer it resembles the single digit > Nixie or VFD clocks I've built in the past. I'm going to try that basic > circuit, and see what I can do with a 555-based switchmode supply. It > would seem I might be able to reverse the diode as part of the -300 supply. > > Joe, N6DGY > > > > > > > > On Monday, December 17, 2012 8:59:03 AM UTC-7, Jonathan wrote: > > Joe, > > > I thought that once you met the oddball voltage requirements that these > > were easily driven with TTL logic levels? So your uC or whatever is the > > driver? > > > Wanna sell the ones you have? :-0 > > > Jonathan > > > On 12/16/2012 6:55 PM, Joseph Bento wrote: > > > That's the thyratron based 7-segment display? I have a set I purchased > > years ago from a US seller, and am still researching a suitable driver to > > build a clock. > > > I don't understand the practicality of such a display, or why the Russians > > developed this. Nixie and numitrons were already very mature at the time > > these were made. > > > Joe > > > On Thursday, November 29, 2012 9:10:03 AM UTC-7, Jonathan wrote: > > >> As the title suggests, I'd love to buy some of those tubes. Dang john > >> for linking to those tubes, they were just so cool I want some! > > >> Jonathan > >>www.madlabs.info > > > -- > > 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]<javascript:> > > . > > To unsubscribe from this group, send email to > > [email protected] <javascript:>. > > To view this discussion on the web, visit > >https://groups.google.com/d/msg/neonixie-l/-/qL4ASahwJPkJ. > > For more options, visithttps://groups.google.com/groups/opt_out. -- 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 https://groups.google.com/groups/opt_out.
