Some may remember those things on youtube.

https://www.youtube.com/watch?v=P9UjxG8sN1c

We all know what a dim bulb tester is and its limitations. Mainly they are good up to maybe a 200 watt audio amp but then they fail.

Turning down a variac does not lower the available current which was the idea.

The bulb is key, low power stuff a 60 watt does it, for higher power maybe a 100 watt.

And their usefulness is very limited on tube stuff. The over head of just the tube filaments make it so.

The scariac is a simple rheostat with a very high power handling capacity. Using that would be like being able to vary the wattage of the bulb in the DBT.

Another thing is worldwide they want rid of incandescent bulbs and those are crucial, partly because they are just a resistance, but also that their resistance increases with more current. We should be able to live without that particular feature.

With the major part of the job done by the bath in the scariac, we can use almost any bulb, halogens should be around for a while.

It beats maybe how I do it, which is to just plug it in. With tubes you actually can, if not fired up in a longtime then look at the rectifier pates first for arcing. If there are any seleniums in there I would just probably disconnect them temporarily. Thing is you better shut down soon because if it has a rectifier tube and a selenium the latter is probably for output bias.

There are also SMPSes out there that really do not like the DBT. I think the scariac can be adjusted to suit them.

I am sure a better thing can be built to do this. Something not so awkward something maybe even a little bit safer. Something that has a drain and a spout because the water solution will need to be changed from time to time - I think.

Think of the power handling of that thing, A tthat water, which can cool on its own just due to mass, or a while. Then it has some surface area but we can make it a little different to give it more surface area. The idea seems very undeveloped right now.

Thoughts ?
Call me crazy ? (flattery will get you nowhere)

You seem to have a lot of time on your hands lately. Recovering from surgery and/or very good pharmaceuticals?

Peter Wieck
Melrose Park, PA

On 3/25/21 1:15 PM, Peter W. wrote:
You seem to have a lot of time on your hands lately.

I had to look up what was a scariac.
Yeah, I can see how they got that nickname.

Of course, he totally missed the concept of a dim bulb
tester.



--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com

Of course, he totally missed the concept of a dim bulb
tester.

Nobody said he was a tech, so you're probably right. But the thing does act as a rheostat.

I think it could come in handy for tube equipment. There are also those Sony amps with the VFETs that will fry on a DBT.

I was thinking about when you have lots of current overhead, like lighting the filaments of a bunch of tubes. The bulb would probably go across the liquistat. (add to spellcheck) Then even on solid state ones you can laeae the stat open and run through the bulb, When you want to crank it up and see how it does on more power, the light gets bright of course, this is where you would engage the liquistat. That would be good on a receiver or amp with remote control because the line voltage to it might get too low and then the damn thing shuts off.