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Does anyone know where I can source these.

They can drive six B7971 Nixies directly, 12 hour with lead zero blank, brightness control, date, enable
Just add HV power supply at 170v and you are good to go.

Data sheet uploaed to files section.

Does anyone know where I can source these.

They can drive six B7971 Nixies directly, 12 hour with lead
zero blank, brightness control, date, enable Just add HV power
supply at 170v and you are good to go.

Data sheet uploaded to files section.

If anyone has this chip, on hand, please build up the circuit on the last page of the datasheet, and report back to us. I hate to burst anybodies bubble, but I see a problem.

Primarily, it looks as if this circuit was intended to run small 'panaplex' type 7-seg displays. The segments on these displays usually don't want to see more than ~250uA (0.25mA) of current. Typical 0.6" nixies like between 1 & 3 mA, and the B7971 somewhat more. The chip outputs pulses (on the cathode side) in the 50V transition range. Those pulses are biased to -150V, so the pulse jumps from -150V(off) to -200V(on). That is the -150V to -200V, is the 50V transition. The 50V pulse is also DC isolated from the display thru 0.05uf (lets say 0.047uf) capacitors. The pulse may stay pretty square with 250uA cathode current, but may droop some (or a lot) with 2.5mA (or 5mA) of current. You may need to up those capacitors to 0.22uf to 0.47uf. The 20K Rs may need to be reduced too (?).

Another omission is the multiplexing frequency. They say its done by way of an RC pair tied to pin-20, but they never show a formula, nor curve, on actually determining the target frequency. The values in the circuit (fig 3) are 150K & 0.015uf. If anyone gets the circuit built, throw a scope on that pin an measure the frequency. I'm betting its between 75Hz & 300Hz (closer to 300), from the circuits usually used for this kind of thing.

If anyone has this chip, on hand, please build up the circuit on the last page of the datasheet, and report back to us. I hate to burst anybodies bubble, but I see a problem.

With so many tried & true, tested, and readily available methods out there, I don't think I'll ever understand why people bother hacking around with inferior and hard to find IC's, unless they already happen to have the IC and wish to do something interesting with it.

don't know 70's retro project ?

--- In NEONIXIE-L@..., "James" <jamesrsweet@...> wrote:

With so many tried & true, tested, and readily available methods out there, I don't think I'll ever understand why people bother hacking around with inferior and hard to find IC's, unless they already happen to have the IC and wish to do something interesting with it.

There are also some newer tried & true display technologies out there, but we continue to use obsolete glass and neon to display numbers.....

I have carburetors on my old cars, too!

Jim