Krill - The Next Generation

[andy_c]

Originally Posted by Steve Dunlap

Aren't simulations fun?

When I'm not having convergence problems . I always liked Hamming's motto - "The purpose of computing is insight, not numbers."

[Steve Dunlap]

Originally Posted by scott wurcer

In the idealized case crossover distortion has nothing to do with the output devices turning off. The logarithmic Vbe modulation between several amps and several micro amps is enough. I still don't get the fixation with "does the output device turn off".

Doesn't even a "real" class A amp do that also?

[ostripper]

Have fun ...."playin" . guys..
BTW , mr. wurcer , is "right on the money".

In the idealized case crossover distortion has nothing to do with the output devices turning off.

OS

[scott wurcer]

Originally Posted by Steve Dunlap

Doesn't even a "real" class A amp do that also?

Yes of course, more is better. Mr Pass knows that.

[Wavebourn]

May be thyristors will fit better into the picture?

[GK]

Originally Posted by Steve Dunlap

Amp from post 3 with driver bias resistor removed.

Originally Posted by ostripper

wow , andy and steve on the same page. We still come so close to 0 , what we are attempting is to "rip " the carriers from the bases of the "half" that just switched off ??

[Steve Dunlap]

Originally Posted by andy_c

Exactly. I think this is just a "does it do what it says on the tin" issue.

Maybe this thread should have been called:

Help me before I Krill someone.

I had planed to just drop this, but couldn't resist ruffling certain feathers one more time.

I threw everything out and started over. Fortunately, parts are cheap in simulation. I even changed the brand of some of the transistors, so these numbers won't be exactly the same as the previous amp.

Working from what has been suggested by Andy, I set the output to 50W into 8 ohms at 10Hz for an almost worst case situation (according to him).

The current flowing in the emitter resistors never drops below 100uA. The current in the base of the driver transistors does not go below 1uA. The total dissipation in the OPS is 38.7W at idle. This is somewhat better than the 131W of the D. Self amp from post 2.

Carrying this one step further, I set the output to 28.3VDC into 8 ohms. The current flowing in the emitter resistors of the "off" outputs was 110.6uA. the current in the base of the "off driver was 1.3uA. Next I suppose I will be ask to try a frequency below DC. It does do what it says on the tin.

[andy_c]

Okay - so why not do what I did earlier in this thread, which is to provide everything that's needed to duplicate your simulation results?

[Steve Dunlap]

What exactly do you need? The schematic I actually used? I will not have a chance to post it until tomorrow at the earliest. Remember I work slowly and sleep occasionally.

[andy_c]

What I would try to do is to download a trial copy of the simulator you're using (can't remember which one it was). So then it would be some kind of project file that I could open up in the simulator and just run it. This varies from one simulator to the next, and I don't know the specifics of your simulator. The trial version might be missing some of the models of the production one, so in that case a text file or files with .model statements could be used to get the necessary models.