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.
Sent from my iPhone On Jul 20, 2013, at 8:38 AM, John Rehwinkel <[email protected]> wrote: >> I have discovered the PT6311 which will handle all of my multiplexing and >> was in heaven. After reading the datasheet, I discovered that it uses a >> negative supply for the VFD. I made a voltage inverter and tried testing it >> out on a tube to see what the connections are. This is where I do not >> understand it. I had been giving the tube about +25V to the grid and Anodes >> with the HV5812 but I am not sure what the connection is with the PT6311, if >> it even works with a VFD tube for a -25 power supply. >> >> The heater has +5V supply with an appropriate resistor in both circumstances. >> >> I put -25V on the grid and Anodes, then tried just -25V to the Anodes and >> the grid to ground and it doesn't light up. >> >> Does anyone have any suggestions? > > The VFD only cares about the difference of voltage between its elements. So > the grid and anode have to be more positive than the cathode to light it. > The PT6311 is arranged so that the cathode is run at -25V, and to turn > segments on, the grids and anodes are pulled "up" to ground, making them more > positive than the cathode. To turn them off, it pulls then down to -25V. > > I have some commercial VFD inverters from surplus companies that produce > -30V, along with a floating center-tapped 6VAC output to power the filament. > I connect the -30V to the filament center tap. > > The tricky part is interfacing logic to the PT6311 - sometimes it's easiest > to float the logic supply. > > - 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]. > 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/32F1F42D-4C7E-4B0C-9BC1-060834BA8611%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]. 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/3B9504FC-9884-48A1-A03A-CCBD23AD0C8E%40yahoo.com. For more options, visit https://groups.google.com/groups/opt_out.
