Crazy tube idea?

[teemuk]

That Turner circuit looks like a generic totem pole. Sure, the tubes are stacked in the drawing but overall the setup looks like a generic push-pull pair of cathode followers, rather than a push-pull pair of cascoded common cathode amps with load on the plates.... or even push pull pair of cascoded cathode followers.

Yep, this circuit does halve the voltage across each tube. But that's because one tube is pulling while the other is pushing. In fact, the voltage at the output node modulates between the HT rail and zero volts, crossing over at approximately half of HT. There aren't two cascaded tubes pulling while two other cascaded tubes would be pushing. I'm not sure if that is exactly what OT was aiming for. I had an impression he wants to take a rather standard topology and replace a single device with a cascode of two or several devices.

Cascode as circuit, yeah that works. Sure- It's ancient and examples are legion. In certain circuits converting something that theoretically seems doable to practice however just introduces a lot of excessive issues and complexity.

Maybe if you replace one of the devices in the cascode with solid-state it could be made with less hassle. That was common in RF designs, and in designs inspired by them, like Music Man amps. But the purpose in that case was really different so I'm not sure if that example is overly applicable to this topic.

[jazbo8]

I'm not sure if that is exactly what OT was aiming for. I had an impression he wants to take a rather standard topology and replace a single device with a cascode of two or several devices.

Cascode as circuit, yeah that works. Sure- It's ancient and examples are legion. In certain circuits converting something that theoretically seems doable to practice however just introduces a lot of excessive issues and complexity.

Maybe if you replace one of the devices in the cascode with solid-state it could be made with less hassle. That was common in RF designs, and in designs inspired by them, like Music Man amps. But the purpose in that case was really different so I'm not sure if that example is overly applicable to this topic.

I think the OP just wanted to see some examples of how two tubes can be stacked up to handle the HV supply, which as Turner's circuits show it could be done even if it is overly complex or perhaps more work than it is worth... But some are just never happy with the "regular" way of doing things, so they are just more oddball ideas to try out if his time and resource permit. I think most of us would not bother...

[soundguruman]

I was wondering if you could run a pair of power tubes in series. My idea is if you have some type of tubes with a relative low max plate current rating of say 250 volts, could you run two in series and apply 500 volts safely?.....like capacitors in series?

Actually, I have had the same exact thoughts...why not?

Yes it's entirely possible.
If we don't think of new ideas and try to develop them, we never make progress.
So, don't be afraid to try new ideas, and develop new designs. Otherwise, without original thoughts and concepts... we would all still be living in caves.

And don't be discouraged by others who criticize your new ideas either.

There are people who think of new original ideas...
and there are people who follow like a bunch of blind sheep...(like most of the people in this forum) with no originality. Don't be afraid to think differently.

When I was growing up, electricians told me that it was impossible to make a cordless electric drill...
that there was no way to store enough energy in a battery...to run a drill motor.
And how right they were. We all know it's impossible to make a cordless electric drill.

And Teslas college professors told him that it was impossible to make a brush-less electric motor.
Imagine the idiocy of such a thing.

[markr14850]

There have been some articles on the TubeCAD journal recently, discussing running stacked output tubes, in the context of OTL design.

Here are a few links:
OTL Design & Sandman Error-take-off Amplifier
Hard-Core OTL Amplifier Design
Supercharged OTL Amplifiers

[R.G.]

There are people who think of new original ideas...
and there are people who follow like a bunch of blind sheep...(like most of the people in this forum) with no originality.

Oops. So let me get this straight - if I translate this correctly, you're saying that most of the people in this forum follow like blind sheep and have no originality. Is that right?

Well, first, I happen to own a flock of sheep, and have had a blind one. She could not follow the flock well at all unless she was in the middle of it and stayed there. How many sheep do you own? Wool-blindness - obscured vision by prolific wool over the eye area - causes big problems with moving flocks for the reason that they can't see the rest of the flock well. So blind is NOT equal to "follows well" in sheep.

Second, given the tone of the comment, you're still taking pot shots at the people in the forum for not immediately recognizing your brilliance, or for daring to question your assertions. Do you classify yourself among the clever, open-minded elite of the forum who have originality and new ideas or the blind followers who wouldn't know originality if it hit them in the backside?

Where do you think you are in the distribution?

If you think you're at the clever, original top end, do you think comments like this will make the benighted mass open their eyes to your greatness?

Just trying to figure out what you actually meant by what you wrote.

[Chuck H]

There are people who think of new original ideas...
and there are people who follow like a bunch of blind sheep...(like most of the people in this forum) with no originality.

Wow! I had to read this twice to be sure I didn't misinterpret your intentions because this statement is so inappropriate on so many levels.

To be perfectly clear, do you consider me to be a designer with no originality? And:

Are you a designer with noteworthy originality? And:

I'll show you mine if you'll show me yours.

[The Dude]

There are people who think of new original ideas...
and there are people who follow like a bunch of blind sheep...(like most of the people in this forum) with no originality.

Another slow day at the asylum.

[J M Fahey]

Who you *think* you are and who you *actually* are is not the same

[DrGonz78]

SGM>>> So let me get this straight... You like to come to a forum and chat with people you like to insult? Or at least MOST of them...? No wonder everyone gives you such crap!! You deserve it! Just more proof that your end game here is to be a troll and just stir up chaos. Good job on being so creative!!

[Mick Bailey]

When I was growing up, electricians told me that it was impossible to make a cordless electric drill...
that there was no way to store enough energy in a battery...to run a drill motor.

Philips had a working cordless prototype in 1961 that looks almost identical to a modern drill. They made it in Perspex (Plexiglass) and exhibited it to show the internal workings.

[Mick Bailey]

Here's an interesting schematic;

Audiyofan.org ? Afficher le sujet - Ampli SRPP avec transfo d'alimentation en sortie

Wonder how it performs at the low end?

[Leo_Gnardo]

SGM>>> So let me get this straight... You like to come to a forum and chat with people you like to insult?

SGM the love child of Triumph the comedy dog and Don Rickles. Hey we should be used to it by now. "Oh no here comes Triumph Junior again."

[km6xz]

And do not forget the long used battery/alternator rigs we used on fence building or other places power equipment was needed hundreds of yards or miles from the nearest power line....connect to the alternator in the truck or jeep before the stud rectifiers and energize the field coil driven by a regulator for steady voltage under varying load or just rheostat adjustment for general use like with table saws or drill press. It is in a way, cordless, but does connect to the vehicle. I've run 3 phase welding rigs or using 1 phase for a table saw or electric pumps far from a grid. My FJ-40 Landcruiser has a locking 3 phase and a 1 phase socket mounted in the rear. All home made and total cost of less than $10 at the time. I later installed a 100amp Leece-Neville alternator to run a 1500 watt transmitter from a mountain top and talked all over the world. Did not even run warm. My GF at the time and I built a 16,000 sq foot indoor arena with 100 ft span using only the FJ-40 for power tools, lighting, welding rig and electric winches. We were building a house also but had contractors doing that. The arena and barns needed to be up first because we needed to use them for cutter training during the rainy season and that little alternator trick worked perfectly far from the power lines that had stopped short of the property by 1/2 mile.

[Mick Bailey]

Turns out Black and Decker had a production cordless drill on the market in '61. The Philips was a lot sleeker, more like a current product. I have an article somewhere about it in an old magazine.

Here's the B&D;

[J M Fahey]

Turns out Black and Decker had a production cordless drill on the market in '61.

Mick, you're missing the point
*Who* mentioned 1961?

All SGM mentions is "while I was growing up" ..... which seems to have happened somewhere around 1861


Which is fine, because already by 1869 Jules Verne was highly successful with his novel proposing a **battery** powered submarine going around the World (20000 leagues under the sea, somme 60000 miles autonomy ) , followed in 1886 (Robur the Conqueror) by a ***battery*** powered helicopter, also travelling around the World.
But of course, none of that was even hinted at in 1861 so SGM's ignorance can be forgiven