I did some tradeoff analysis on filament drivers for a project underway,
and I concluded a dropping resistor is better than a current-regulator for
filaments, at least in my case.
To cancel-out the voltage-gradient along a filament, AC rather than DC is
commonly used. That makes a
I've also had generally very good reliability with vfd displays...
instrument displays, larger tubes in clocks...
Tubes are in this clock are Russian IV-6 with roughly 1.0 to 1.1 V across
the filament. Voltage is limited by individual series resistors from the
nominal 5V supply. Filaments are
I have had the same socket appearance with a few of the "gold label"
GR-414 tubes. Jens
On 9/30/2017 4:45 PM, Dekatron42 wrote:
If you look carefully at the photo of all four tubes you can see that
the one to the right has a different label than the other three, it
also has a date code on
If you look carefully at the photo of all four tubes you can see that the
one to the right has a different label than the other three, it also has a
date code on that label which the other three are missing. My guess is that
the three with the same label have another type of bakelite socket
About those CD47 tubes on eBay... To me, they look slightly used, or maybe
abused during shipping or storage. You can see minor chipping all along the
expansion slots of the base.
By contrast, here's what the base of a new CD47 looks like:
Actual list:
3LO1I – 72 pcs. for $15,
6LO1I – 104 pcs.,
6LO2A – 2 pcs.
7LO55I – 1 pc.
8LO29I – 47 pcs. for $20,
8LO30I – 1 pc. for $100,
8LO39V – 22 pcs. for $20,
13LМ31V – 7 pcs.,
13LN2 – 1 pc.
13LO9I – 5 pcs.
13LO18V – 1 pc.,
13LO36V – 1 pc.,
13LO37I – 2 pc.,
16LO2V – 29 pc.,
The VFD for the display on my kitchen's oven runs 24/7, and after 12 years
there are very noticeable dark-bands near the filament, which is probably
the result of higher bombardment of electrons onto the phosphor. The
filament does not glow bright enough to see it, and it's always on.
So, if
That's interesting Robert, thank you for sharing. I am not so comfortable
and fast with case building, so the less holes I have to drill, the better
;-)
>
> ... on one of my small VFD clocks it's difficult to modify the base board
> to remove filament voltage and I'm tired of replacing failed
