try to visit my website: http://vfdclock.jimdo.com.you can find answers on the web site.
在 2013年7月30日星期二UTC+8上午10时25分58秒，Spencer写道： > > After spending several days playing with the negative voltages and testing > it, it doesn't work as I was hoping. It seems that a lot of people use AC > instead of DC and I can't find an example that uses DC for negative > voltages. This was the closest I could find, > http://threeneurons.wordpress.com/vfd-stuff/ , but it looks like its AC. > > I was working with 2 tubes in series with a 30 ohm 2W resistor that has > +5V applied to the first filament and then the other end is grounded, and > the grid/anode was fed +30V with a HV5812 shift register. > > I put the -27V on the first end and GND on the other end of the filament, > it lit up pretty bright on the filament and I tried with different resistor > values but even the 2W resistors were heating up and the brightness of the > segments wasn't there. > > I then tried -27V on the first filament and different combinations of -27V > and the +5V with resistors on the other end of the filament and the anodes > were grounded, but nothing was working or it was very dim segments. > > While I would love to get this working, It looks like I should use a > second MCU to handle the display/boost and another to handle all the other > operations. > > Thank you everyone, > > Spencer > > ------------------------------ > *From:* Spencer W <[email protected] <javascript:>> > *To:* "[email protected] <javascript:>" > <[email protected]<javascript:>> > > *Sent:* Monday, July 22, 2013 7:33 PM > *Subject:* Re: [neonixie-l] IV-11 VFD > > So many ways to tackle one problem. I get stubborn when one way doesn't > work right the first time and will spend days getting it to work. > > I'm trying to keep the interrupts free for some rotary encoders so either > the pt6311 or the secondary MCU will be he way to go. Plus if I get the > pt6311 working for this, I have a bunch of different tubes that I can use > this one. > > I have been eyeing the IV-17 for some projects and would love to see it > work with this. > > Either way, once I get everything figured out, I'll share with the group > so someone else doesn't need to do the leg work. > > -spencer > > Sent from my iPhone > > On Jul 22, 2013, at 4:42 PM, "Bill van Dijk" > <[email protected]<javascript:>> > wrote: > > Spencer, > > there are a couple of (actually many) options. I have another clock that > also multiplexes 60 LEDS as well as 6 7-segment displays in a 1-6 MUX. I > control the multiplexing of the tubes by interrupts at about 300Hz, which > ensures better timing. The power supply is probably more tolerant to a > couple of missed or late cycles without any visual effects. Shift registers > are also great tools for multiplexing, especially when used in conjunction > with a BCD to 7 segment decoder. That way you can completely control 6 > tubes with only one 8-bit port. I would suggest if you do feel inclined to > add a small MCU to help out, dedicated it to the power supply, and keep all > the clock functions as well as the multiplexing in the main MCU. > > So many options..... :-) > > Bill v. Dijk > > *From:* [email protected] <javascript:> [ > mailto:[email protected] <javascript:>] *On Behalf Of *Spencer > *Sent:* Sunday, July 21, 2013 2:07 PM > *To:* [email protected] <javascript:> > *Subject:* Re: [neonixie-l] IV-11 VFD > > Thanks for the schematic. It would be overkill if it was just for a clock > but I want to save cycles on the MCU since it was multiplexing the tubes > and boosting the voltage. I was taking cycles away from the MCU and it was > causing flickering. I looked at either a PT6311 or having a dedicated > attiny to run the multiplex/booting and feeding via serial the tube display. > > So it just looks like the filament voltage is biased (is that the current > term?) to the grid voltage. So -18v filament one end and -20 the other end > and grid/anode is -20v. I am using MC34063 inverted to generate the > voltage. I'll give it a shot it and see what happens! > > ------------------------------ > *From:* Bill van Dijk <[email protected] <javascript:>> > *To:* [email protected] <javascript:> > *Sent:* Sunday, July 21, 2013 7:07 AM > *Subject:* RE: [neonixie-l] IV-11 VFD > > Spencer, > > Attached is the schematic for my IV17 clock with a PT6311. It is a chip > that takes a bit of figuring out, also on the software side. My clock > displays time (why not eh?) and the full date in a marquee format as well > as ambient temperature. I would suggest the PT6311 is possibly a bit of > overkill for a 7 segment based clock design. > > Bill v. Dijk > > *From:* [email protected] <javascript:> [ > mailto:[email protected] <javascript:>] *On Behalf Of *Spencer > *Sent:* Saturday, July 20, 2013 2:29 PM > *To:* [email protected] <javascript:> > *Subject:* Re: [neonixie-l] IV-11 VFD > > Got it working! It lights up now and it looks like I will have to change > the filament resistor. I was using a 30 ohm with +5V but ooo boy does it > get bright with that. I'll drop it down to around +1.5V and can take it > from here. > > Thanks again. > > ------------------------------ > *From:* John Rehwinkel <[email protected] <javascript:>> > *To:* [email protected] <javascript:> > *Sent:* Saturday, July 20, 2013 12:54 PM > *Subject:* Re: [neonixie-l] IV-11 VFD > > > Thanks for the reply. I put the -25v on pins 1 and 11 (cathodes) and GND > on pin 2(grid) and GND on a random anode to see if it would light up and > nothing illuminated. > > The filament needs to be hot to emit electrons for the VFD to operate - > this is normally accomplished by heating it electrically. I did kind of > gloss over this -- you have to have voltage across the filament as well - > this is true no matter how the other voltages are supplied. The "ideal" > method is to have a small center-tapped transformer providing the AC > filament voltage (generally something between half a volt to a few volts), > and hook the -25V to the center tap. I often use a generic 6.3V filament > transformer, with series resistors to drop the voltage to whatever the VFD > filament needs. Some people don't want to bother with an AC filament > voltage, and just run it with DC - this will work, but can lead to > brightness gradients in some tubes. > > So, just to light something, at a minimum, you'll need -25 volts at one > end of the filament, -(25 + filament voltage) at the other end of the > filament, and 0V at the grid(s) and anode(s) you want to light. > > - John > > -- > 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]. <javascript:> > To post to this group, send an email to > [email protected].<javascript:> > To view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/C81F0687-BB98-4FAD-A200-745055041C3E%40mac.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] <javascript:>. > To post to this group, send an email to [email protected]<javascript:> > . > To view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/1374344910.82573.YahooMailNeo%40web142601.mail.bf1.yahoo.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] <javascript:>. > To post to this group, send an email to [email protected]<javascript:> > . > To view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/003001ce860a%24f3b03750%24db10a5f0%24%40com > . > 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] <javascript:>. > To post to this group, send an email to [email protected]<javascript:> > . > To view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/1374430022.36570.YahooMailNeo%40web142605.mail.bf1.yahoo.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] <javascript:>. > To post to this group, send an email to [email protected]<javascript:> > . > To view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/001201ce8724%2472aa9f40%2457ffddc0%24%40com > . > 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] <javascript:>. > To post to this group, send an email to [email protected]<javascript:> > . > To view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/40DF0AFC-D2A0-4D24-94C8-AF7F62F0934E%40yahoo.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. 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