Thanks, John. A few follow up questions...Is AC voltage harmful to the grid/anodes? I have rectifiers handy and will convert it to DC, but was just curious about the implications of AC in this set up. I have only really done DC stuff for the most part, so AC is a new chapter in my learning.
I am also pretty unfamiliar with capacitive reactance but did some googling after your reply. I will do some continued follow up, but if you have a second to look at this attachment, is the idea here the same concept as the section related to the capacitive transformerless PS? http://www.electro-tech-online.com/custompdfs/2004/09/00954A.pdf I realize I am using a transformer, but I figured the step down concept was the same. Best, Dylan On Sat, Jan 14, 2012 at 11:53 AM, John Rehwinkel <[email protected]> wrote: > > Just wanted to revisit this thread to provide an update on my learning > process and ask for some additional advice... I was in Radioshack to grab a > one off part I needed for something else, and on a whim decided to look at > their transformers. I noticed they had one that does 25.2VAC out at 450mA. > I ended up grabbing it and have finally gotten around to trying it out. I > have not done any experimentation with transfomers at all yet, so I thought > this would be a good opportunity. > > > > Although I will probably not go with this approach as I start to design > and build my own clocks due to the bulk and impracticality of using it in a > small space, I figured this might work for my first VFD clock built on > perfboard. > > That's a good way to learn about things. > > > I have a few questions...First, is there anything I should be worried > about or need to think about when going the transformer route (other than > doing something stupid and touching the mains side)? > > Not particularly. Transformers bring a nice degree of safety. Even if > you manage to short-circuit it, it won't burn up immediately or anything > like that. > > > Second, does anyone have any recommendations on stepping down the > voltage for the filaments without another transformer? > > Normally I step down filament voltage with resistors, which gives the > advantage of a soft start. However, if you're using the same transformer > for your anode/grid supply, that trick doesn't work as well, since you have > the same ground reference for two different things. > > One way is to use capacitors instead of resistors, which will pass the AC > (which you want) but not the DC (which you want separate for your > anode/grid supply). You'd just need to compute the capacitive reactance > you need to drop enough voltage at the appropriate current. > > > As an aside, I'm very excited to build my dekatron spinner kit! I'm > anxiously awaiting my OG-4s I have on order so I can put this baby > together. It will be my first dekatron project. > > You've got the right attitude - try stuff, and have fun with it! > > - John > > -- > 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. > > -- 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.
