topology question

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Has anyone ever seen a circlotron output topology with
complementary symmetry?

Usually the circlotron is implemented as in tube designs with only NPN device
,(or PNP) like in SUMO stuff.

Any comments on the possible vantages or drawbacks of the symm. circlotron
in respect to a classic bridged output configuration?

Federico
 
oops, the pic

Federico
 

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About 6 months ago I drew up the very same topology! After the initial excitement wore off and I was thinking straight again, I realised that it is nothing more than a pretty circuit for the eyes. It is in fact two half-bridge circuits in parallel with all the usual difficulties of parallel amps and none of the benefits of a full bridge even though it has the same quantity of output transistors.

Better to build either a conventional circlotron or a full bridge or a normal half bridge. I really thought I had invented something useful. :bawling:
 
Thank you Circlotron

However, I think somebody may prefers it.

For example,
suppose one has to built( for some reasons) a balanced output but with half the output resistance (without feedback) of the common balanced bridge (same number of device).

The comp. symm. circlotron is a possible solution.

Yes, I know that the half-bridge is better, but it is not balanced.

What do you think?

Federico
 
fscarpa58 said:
What do you think?
After thinking about circlotron topologies so much that I now look like one, I believe that if you are serious about doing one then try this method here that can use one single power supply for all channels. It works great. Maybe you could adapt it to your comp/symm cct? I don't think it is necesary though because the cct here is totally symmetrical already. http://www.diyaudio.com/forums/showthread.php?s=&threadid=10658&highlight=
So... what do =you= think?
 
One minor thing, the right hand side transformer should have it's + ends toward the top. This is because the top tube anode is going the same direction bottom tube cathode and vice versa. That is why you can cross-connect them with big caps. Also, the two paralleled transformer secondaries should be the same polarity of course.

My preferred way is to wind all windings on the one core. One day I might just make up a tube version and see what it is like; I've only made ones using non-audio "hexfet" type fets so far. The circuit works so well that everyone should make at least one.

I have a 5kVA c-core transformer with a suitable set of windings that I tell myself that I am going to make into a foolishly big amplifer one day. I alread put the fets on a pair of heatsinks- 16 fets per leg @ 32 amps 500v 540W dissipation per fet. The heatsinks are hopelessly undersized for continuous full power but the short term rms power should be "adequate" as they say. :smash:
 
capacitors are not needed

Hi Circlotron,

I tried the SS circuit you reported but I used BJT.
After a lot of sim a realized that capacitors do nothing.
All the crossing trick is made by the trafo.

The following circuit works perfectly and
V(A,B) is absolutely constant and equal to 45 V.

The requested inductances are very small, amazing.

Good weekend

Federico
 

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After a lot of sim a realized that capacitors do nothing. All the crossing trick is made by the trafo.
In a pefect world with a perfect transformer the caps will indeed do nothing, but with a real-world transformer they lock the two primaries together so the whole thing is rigidly "braced"so to speak.

The amp I built had the speaker connected from one emitter to the other (you could do it between the collectors, or even both) and in that case the caps relieve the transformer of having to transfer (conduct?) any medium to high frequency through the core. All it has to handle is a bit of low frequency when the caps start to run out of breath. It is really a see-sawing common- mode choke; it doesn't have to have any good qualities as a transformer at all except for a moderate amount of (low grade)iron and copper. That is provided you connect the load between the emitters or the collectors and don't use a separate secondary winding. That's one of the reasons why I like it so much.

/Circlotron - keeps one under his pillow.
 
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