What does the dotted line from the ground to the 50V line mean? Did you short it? I bought some of these and have been studying your schematic, but I cant figure out what that means.
On Sunday, March 12, 2017 at 2:11:32 PM UTC-5, Paul Andrews wrote: > > Here is a schematic. Some notes about it: The filament (aka the cathode) > should always have 1V across it. It has to be warm. When it is warm it has > a resistance of about 30R. So the purpose of the resistor network there is > that it cuts the 12V up into 3V, 1V and 8V (approximately). The filament is > raised to 3V above 0 because we need to be able to vary the grid voltage > from -3V to 0V with respect to the filament. So in this case, with the > filament held at +3V, we can vary the grid voltage from 0V to +3V. When the > grid is at 0V (-3V wrt to the filament), the lamp is fully off. When the > grid is at +3V (0V wrt the filament), the lamp is fully on. > > I made the grid voltage variable with the little resistor network off to > the left, just to demonstrate this. > > I created the 50V anode potential with a 200K/100K resistor network across > a 150V nixie power supply I happened to have. BTW, the tube will glow with > an anode voltage all the way down to about 23V, so 3x9V batteries in series > would be enough to get a glow out of it. > > In reality my 12V power supply was more like 10.5V so the resistor values > I used were a little different. Also, the resistance from the anode to > ground is not infinite, so the actual voltage of my nixie power supply was > more like 220V, which I produced gradually to make sure I didn't go over > 50V. Obviously an actual 50V power supply would be better! > > All of this is just to demonstrate the principles of the DM160, rather > than to act as a recipe for how they should actually be controlled! I broke > two lamps while experimenting, in different ways. In the first lamp I > applied >1V to the filament and it burned out after a few seconds!. Second, > a filament shorted to the grid so I couldn't control the grid voltage any > more. The first problem was just me being dumb. I have no idea why the > second problem occurred, so you have been warned! Fortunately these lamps > are cheap, but I am concerned that there is no apparent reason for the > second problem... > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/3fbfc74c-6353-433a-b258-5d1fb8127fd3%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
