Re: [neonixie-l] Re: MMBTA92 & MMBTA42 anode switching circuit problem

>From the datasheet, collector leakage current is about 100nA. Assuming all of the NPN leakage current is amplified in the PNP, you would get 4-5uA of actual leakage to the anode from the PNP. That doesn't seem like enough current to me to cause a visible glow in a nixie. Your scope probe (10me

Re: [neonixie-l] Re: MMBTA92 & MMBTA42 anode switching circuit problem

And use a 50/50 divider, to make the voltage between anode and cathode of the tube as low as possible. Do not set it at 120V, but go for 90V, using equal resistors. If your HV is higher than 180V, try reducing that to at least 180V or perhaps 170V. Op vr 19 jan. 2018 om 18:52 schreef Frank Bemelma

Re: [neonixie-l] Re: MMBTA92 & MMBTA42 anode switching circuit problem

Tomasz - which nixies are you using in this application? I seem to remember some discussion from years ago that some tubes (maybe ZM1000?) were particularly prone to ghosting and leakage effects even at microamp currents. Jon. -- You received this message because you are subscribed to the Goo

Re: [neonixie-l] Re: MMBTA92 & MMBTA42 anode switching circuit problem

Well, the voltage divider is at half of 180V, more or less 90V. Even is some current was leaking through your anode transistor, the voltage between tube anode and tube cathode, is still to low to cause any glow. The tube’s digit will only glow with a fully turned on anode transitor and cathode tran

Re: [neonixie-l] Re: MMBTA92 & MMBTA42 anode switching circuit problem

W dniu czwartek, 18 stycznia 2018 19:29:02 UTC+1 użytkownik Frank Bemelman napisał: > > It is not the transistor that keeps conducting or leaking. The voltage you > see at the anode comes from leakage from floating cathodes from the other > tubes. > Oh it was just seconds ago when I underst

[neonixie-l] Re: Cutting the front off a Burroughs SD-11 sphericular display

Wow, that digital sundial is very impressive, and does look like it works on the same principle. Building a larger digital display does seem like it could solve most of the problems of making your own symbols... get a bunch of surplus magnifiers, mount them in a frame, and drill a million holes

[neonixie-l] Re: MMBTA92 & MMBTA42 anode switching circuit problem

W dniu czwartek, 18 stycznia 2018 13:54:32 UTC+1 użytkownik GastonP napisał: > > Another option (just to help troubleshooting but involves no soldering) is > to change the driving sequence to avoid adjacent tubes to be driven one > after the other. For example if you are driving the tubes in 1-

[neonixie-l] Re: Cutting the front off a Burroughs SD-11 sphericular display

Hi Anubis; The operation is very related to the "Digital Sundials" . I have one of the "Digital Sundials International" dials. It works very well. Of course it reads in local "Solar" time. I think the SD-11 works in a simila

[neonixie-l] Re: MMBTA92 & MMBTA42 anode switching circuit problem

I can recommend reading the Burroughs document N101 on multiplexing Nixies which can be found here, if you haven't done so already: http://worldpowersystems.com/ARCHIVE/Burroughs/index.html . /Martin -- You received this message because you are subscribed to the Google Groups "neonixie-l" gro