Yep. A lot of designs just use individual HV transistors for each cathode.
I recommend mpsa42 personally as they are ideal for cathode driving and not expensive. They come in several different packages including sot23 SMD if you need small.. David On Sat, 9 Mar 2019, 15:31 Jasper C., <[email protected]> wrote: > I was planning to not multiplex my nixies, probably leaving all cathodes >> connected directly to the HV line, and placing current liming resistors on >> the cathodes. Was interested to see if I'd need to tweak any of the >> individual resistor values uniform current/brightness. >> > > I only just reread what I wrote there, and realise I made a typo. I > should have said I was going to connect all the anodes to the HV line... > > > On Thursday, 7 March 2019 00:41:00 UTC+8, nixiebunny wrote: >> >> Another important fact about Nixie tube cathodes: turning on one cathode >> by pulling it to zero volts causes it to steer all the available current >> away from the other cathodes, causing them to be dark. This is why you only >> need a 50V switch on each cathode. >> The caveat is that if no cathodes are pulled to zero volts, then there >> will be leakage current flowing through the tube that will destroy a 50V >> transistor. This is why I used the TD62083 with its set of commutation >> diodes, and connected the diode common anode pin to a 50V source in my >> Nixie watch circuit. >> It's also why I made the blanking mode that drops the anode voltage to >> 100V, so that the cathodes all remain dark when blanked. >> >> > Ah, well that comes back to the page I referenced in the opening: > http://www.decodesystems.com/re-how-nixies-work.html. Maybe that was > written in reference to having leaky cathode transistors? (With no voltage > clamp, as in Fig. 4.) If I had say 300V+ transistors with sufficiently low > leakage when off (< 10 uA) and a 170V power supply, would I be able to > blank the tube safely by turning all transistors off? > > I'll have another look at power supplies. :) I was a little concerned > about how to calculate the value of the loop compensation components. For > my first attempt I figured I'd avoid the problem altogether by using one of > Yan's power supplies, and focus on the segment driving circuitry. > > > -- > 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 email to [email protected]. > To view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/7026df09-ef22-408c-9e92-7daa3f5f2db6%40googlegroups.com > <https://groups.google.com/d/msgid/neonixie-l/7026df09-ef22-408c-9e92-7daa3f5f2db6%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- 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/CAOQ6x0He3aJSDhbhb%3DyfW3ZzNeJYouoWX5syECYM2WD1XEOHGw%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
