[neonixie-l] Re: Constant current source design

My concern with current limiters that rely heavily upon the datasheet specs (Vgs for Depletion-mode regulator; Vbe for current-mirror) is that variations due to process & temperature will have significant impact on the actual current. Using a slightly more complex+costly design will mitigate

[neonixie-l] Re: Constant current source design

Although a mosfet current mirror would use fewer components as you only need one Rset (section three of this paper). I guess I need to place yet another order with digikey to try some of these out. On Friday, April 7, 2017 at 5:34:49 PM UTC-4, Paul

[neonixie-l] Re: Constant current source design

Here is a link to a paper about using a depletion mode MOSFET for the same purpose. It gives this equation for calculating the resistor value,

[neonixie-l] Re: Constant current source design

Update 2 - I've found a 130,5V transil at work, so I've been able to substitute a nixie tube with a nice dummy load. Results are: 208V supply, 139V dropped on transil, 49V dropped on 3x33k resistors in parallel, rest dropped on my limiter. Current is 4,55mA. Everything seems to work just as

[neonixie-l] Re: Constant current source design

Update: success! I've found a way to limit current using few components and without any voltage dividers. The key was using a N-JFET. I guess if one used a N-MOSFET which opens with negative gate voltage, the result would be simmilar. I wonder if a similar circuit with a P-MOSFET would work,

Re: [neonixie-l] Re: Rare tubes on eBay..

Yeah, it's really beyond me why anyone would pay money for anything else than the famous trio (zm1042/z5660m, IN-18 and Dalibor's RZ568M) when everyone knows that size is all that matters and these 3 tubes is all you need - ever! :-) -- You received this message because you are subscribed to

[neonixie-l] Re: Constant current source design

Sorry for late reply, I've destroyed my boost converter somehow and had to rebuild it from scratch. I've tried the current limiter, but without success - I don't know why, I followed the article and I think that this just won't work for such voltage drops or something. Funny thing is that I've

[neonixie-l] Re: Rare tubes on eBay..

It is really about preferences. NL tubes have really fine anode mesh made of thin wire, and Z566Ms have hexagonal, sturdy mesh cut out from thin plate. I have few american tubes and I'm in love with their transparency and visibility of digits. On the other hand, Z566Ms have better digit shape.