I used this as a reference for mine. If I remember right, it's around 1.15volts for the filament and 100mA. So with 5v power and 2 in series, 27ohm resistor though you want 2 watts.
http://led.linear1.org/led.wiz Sent from my iPhone > On Dec 6, 2013, at 5:06 AM, Gideon Wackers > <[email protected]> wrote: > > I just measured the filament resistance of a IV-11 tube, according to my > multimeter that is roughly 5-5,5 ohm (assuming it measures perfectly at such > a low resistance). But I calculated something different; > > I'm going to wire the filaments of two tubes in series and feed them 5 volt > though a resistor. So I used the voltage/resistor divider formula. to > calculate the resistor needed for a 2 volt drop (tubes want 2*1,5V) and that > is 10 ohms, going back to the voltage divider that gives ma a resistance of > 15 ohms for both tubes and 7,5 ohms for each filament. Close you might say > but still a 50% difference. > > Options: > -my multimeter sucks > -filament resistance differs because it is cold > -both options > -my calculations are wrong > > Well while I wait for an answer I'm going to build a little jig with lego so > my tubes will be aligned perfectly straight :) > -- > 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/4e980192-1b38-42f2-b092-9e62298f2ea3%40googlegroups.com. > For more options, visit https://groups.google.com/groups/opt_out. -- 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/1641568D-5C45-4C1B-A36D-7F091F3D19FB%40yahoo.com. For more options, visit https://groups.google.com/groups/opt_out.
