L'Amp: A simple SIT Amp

[Zen Mod]

F1 is important in PSUD

make your sim , attach it zipped here , and you'll get some help

[Michael Rothacher]

Yes, more info needed. Ringing in what? The simulated power supply?

You could just replace the CRC resistor with a 12-14 ga. 2-4mH air core coil if you want a CLC.

[juanitox]

hi Kasumi , could you try my config in PSUD ( i don't know how to use correctly PSUD ) with 18V AC 22000uf ( 0,01 esr) 10mh ( 0,47 ohm) 37000uf (0,01 esr) .. and tell me if you see any ringing? thanks !

[KASUMI]

Originally Posted by juanitox

hi Kasumi , could you try my config in PSUD ( i don't have windows PC ) with my CLC 18V AC 22000uf ( 0,01 esr) 10mh ( 0,47 ohm) 37000uf (0,01 esr) .. and tell me if you see any ringing? thanks !

First time I used PSU D was yesterday ,so I doubt I know what I'm looking at or doing.
There is a very knowledgeable bloke on another forum I use that inferred that there was ringing in the sim I had using a 20mH inductor in a CLC config.
I started with that as that was what you said you used in a past post.

I'll just go with what Mike recommended 2-4mH and leave these sims to the pros

[Michael Rothacher]

Those values worked nicely for me. I haven't tried any big iron myself, but I'm sure its good.

It's hard to say what your friend might be referring to, so I can't help there without seeing the simulation results.

You could observe the real ripple waveform with your scope if you have one.

[i_should_coco]

Originally Posted by KASUMI

First time I used PSU D was yesterday ,so I doubt I know what I'm looking at or doing.
There is a very knowledgeable bloke on another forum I use that inferred that there was ringing in the sim I had using a 20mH inductor in a CLC config.
I started with that as that was what you said you used in a past post.

I'll just go with what Mike recommended 2-4mH and leave these sims to the pros

Hey Rob, just to clarify, I think you might have misunderstood - I didn't say there was ringing in your sim (I didn't actually sim it yet), I just suggested using PSUD to simulate your cct. and one of the things to look out for is ringing when you add a current step (you can see the oscillation in the waveform. I was in a hurry ad missed the details in your PM. Knowing the DC resistance of your power transformer and proposed choke would be good, too as they will affect it.

[i_should_coco]

Here's a sim using similar values to the ones you sent: 37000uF - 20mH - 37000uF, 2.5A load. (I substituted a Hammond 159ZE (28mH, 0.43 Ohms) choke as that's a real part.





Look like you get about 2V ripple! That seems quite high...

[KASUMI]

whoops,yep I'd thought you'd done a sim ISC and had seen some ringing and thought it may have been overlooked

[Zen Mod]

2R for 37mF !!

yikes!

[i_should_coco]

Good point, I'm more used to tubular stuff. What's a sensible value? 0.1R?

ok, 0.1R give more sensible results. No ringing when stepped, but looks a bit over-damped to me - I'd aim for a slightly faster rise.