topology question

[fscarpa58]

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

[fscarpa58]

oops, the pic

Federico

[fscarpa58]

Nothing ?!?!

[fscarpa58]

Helloooooo!

[Circlotron]

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.

[fscarpa58]

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

[Circlotron]

Originally posted by fscarpa58
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. Tetrahedron output stage topology.
So... what do =you= think?

[fscarpa58]

Fine circuit Circlotron


Yes, with transformer we are able to do a lot of things
as in tube circuits.

The following, for instance are perfectly equivalent circuits. The circlotron has, in fact, a mixed anodic-cathodic load.

[Circlotron]

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.

[fscarpa58]

One minor thing, the right hand side transformer should have it's + ends toward the top. This is because...

In this case I have to reverse also the secondary ends of the
right hand side trafo ( that is it's - ends toward the top ) otherwise the sim doen't work.

Federico