> 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.
