VFD power supply plans or kits?

[Ben Pottinger]

I picked up a ton of VFD displays from tubes-store.com (good prices and cheap shipping btw.) and now I'm trying to figure out how to power them. It seems a fair bit more complicated to power them then the nixies are to power. Are there any good/simple power supply circuits anyone can suggest? Also, any helpful articles/datasheets would be awesome too. So far I've only looked for iv-22 stuff and you have to wade through tons of links to the "arduino/IV-22" "module" which seems pretty darn expensive.

The VFDs I picked up were: IV-22, IV-21, IV-11, and IV-6.

Thanks ahead of time, I appreciate any help anyone is willing to give this circuit cooking newb!

Ben

[John Rehwinkel]

I picked up a ton of VFD displays from tubes-store.com (good prices and cheap shipping btw.) and now I'm trying to figure out how to power them.  It seems a fair bit more complicated to power them then the nixies are to power.

Yeah, you need two power supplies, a filament supply and a grid/anode supply.

 Are there any good/simple power supply circuits anyone can suggest?

Most people run the filament with a DC supply and a dropping resistor.  This works, but the purists (like me) prefer AC filament drive.  

An ordinary transformer works nicely - especially if it has a low voltage center tapped winding for the filament.

There used to be a chip (LM9022: http://www.ti.com/product/lm9022) that provided push-pull AC drive for the filament, and with a capacitor/diode voltage multiplier, also generated the anode/grid supply.  It is worth looking at its data sheet.  Grahame found a few of the surface mount variety in the UK a while back.

Konstantin used MAX628/TSC428 FET gate driver chips to implement a similar filament supply, look at kosbo.com for his designs.

All Electronics used to sell a nice VFD supply on the cheap:

http://www.vitriol.com/images/tech/DC-32.gif

Electronics Goldmine also had a cheap VFD supply:

http://www.vitriol.com/pdf/VFDsupply-G5097.pdf

However, they're both out of stock now.  The DC-32 is smaller, but does not include the filter capacitors (you have to provide them externally, and if a particular one is omitted, the regulation loop fails and it self-destructs).  These

supplies produce a center-tapped low AC voltage (to power the filament) and an assortment of negative voltages.  They're intended to be used by floating the filament negative and pulling grids/anodes "up" to ground to light them.

By reversing the diodes, you can get positive outputs, which is easier for most of the circuits and chips we're used

to using.

I bought a raft of the DC-32 supplies, want some?

You can use series resistors to adapt higher VFD filament voltage sources to the needs of your particular VFDs.

 Also, any helpful articles/datasheets would be awesome too.

Look at the data sheets for VFD driver chips (STM86312, MM58342, MAX6920, etc.) for more ideas.

Noritake has some good info:  http://www.noritake-elec.com/vfd_technology_an.php?series=VFD+Technology

Also, read earlier traffic on neonixie-l (search for "Beginner friendly VFD PSU circuit" for a good thread):

https://groups.google.com/forum/#!topic/neonixie-l/tarPYOcsO60

- John

[petehand]

LM9022 - tens if not hundreds of thousands of them available here -

http://www.chinaicmart.com/buyer/search.html?sel1=1&keyword=LM9022&Submit.x=0&Submit.y=0&Submit=Submit

[David Forbes]

I wonder about those listings. Is there any reason to believe that these
parts are real? Why would some random Chinese company happen to have
50,000 of a National Semi chip that went obsolete many years ago?

Do any of you have experience buying from this China IC Mart?

On 5/19/14 1:58 AM, petehand wrote:
> LM9022 - tens if not hundreds of thousands of them available here -
>
> http://www.chinaicmart.com/buyer/search.html?sel1=1&keyword=LM9022&Submit.x=0&Submit.y=0&Submit=Submit
>

--
David Forbes, Tucson AZ

[Spencer W]

I've bought them and they work fine.

[Tidak Ada]

It may be they use their own fake chips that they branded NS. There are lots
of fake chips and semi's on the Chinese market and eBay!

eric

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[Per Jensen]

On 19 May 2014, at 21:02, Tidak Ada <off...@zeelandnet.nl> wrote:

> It may be they use their own fake chips that they branded NS. There are lots
> of fake chips and semi's on the Chinese market and eBay!

Maybe we can persuade Spencer to hit one with the propane torch, until the epoxy case is burnt to a white crisp, then it's easy to remove the die from the mess, clean it in alcohol and then put under a 100x microscope to check for die markings.

// Per.

[Spencer W]

I would be more than happy if you want to send a 100x microscope to me or I can throw it to someone that does have one on the list.

Sent from my iPhone

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[David Forbes]

I have access to some nice microscopes at my lab at the University. I could take
a photo of it and post it, as I don't look at enough bare dice to be able to
identify 1980s silicon artwork from the modern Chinese stuff.