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Old 18th May 2011, 09:15 PM   #1131
fibko is offline fibko  Slovakia
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Join Date: Feb 2011
Quote:
Originally Posted by electroconico View Post
I used a 100pF cap instead 330pF.
Mosfet irfp250N with bypass dione mur120.
Power supply +-60vdc

Input signal less than 0.6vpp

Is it a saturation problem ??

I can't go up more than that.
When I removed 1u capacitors, I have the same problem. I thing this capacitors are very interesting for stability and I add 1000u and 100n
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Old 18th May 2011, 09:20 PM   #1132
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Quote:
Originally Posted by luka View Post
does the coil get hot?
why do you use such small signal?
The inductor itŽs cold.

That is the signal level that it can use before to get the saturation.

Quote:
Originally Posted by fibko View Post
When I removed 1u capacitors, I have the same problem. I thing this capacitors are very interesting for stability and I add 1000u and 100n
I have the 1uF capacitors. IŽll add the 1000uF caps to watch if something could change.

Later IŽll try other inductor .

ty

Last edited by electroconico; 18th May 2011 at 09:24 PM.
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Old 18th May 2011, 10:44 PM   #1133
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Well, I changed the toroid core .

Now i can get more power , a little more.
Toroid core 22uH . It is getting hot quickly.

The output looks very clean . Now the oscillation goes up to 230KHz.

I got the saturation at more high level than before.

So I think the problem is the toroid core.

What do you think ?

Pics below :

Old inductor.
New inductor before sat.
New inductor Sat.
Oscillation and output.
Oscillation
Attached Images
File Type: png Old Core saturation core.png (21.7 KB, 1048 views)
File Type: png New_22uh_core_output_before_saturation.png (7.7 KB, 1019 views)
File Type: png New_22uH_core_saturated.png (8.2 KB, 995 views)
File Type: png Oscillation_250KHz_22uH_core.png (6.6 KB, 977 views)
File Type: png Oscillating at 250KHz core solution.png (10.3 KB, 968 views)

Last edited by electroconico; 18th May 2011 at 10:49 PM.
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Old 18th May 2011, 10:49 PM   #1134
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Location: Nis, Serbia
Did anyone test amp with T130-2 or T106-2 with 20-22uH?
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Old 19th May 2011, 04:48 PM   #1135
Pafi is offline Pafi  Hungary
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Location: Budapest
Quote:
So I think the problem is the toroid core.
And something else.

But you didn't tell enough/any informations about neither the old nor the new core. Also the load is unknown.

I don't see any sign of saturation.
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Old 19th May 2011, 04:59 PM   #1136
opor is offline opor  Thailand
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Quote:
Originally Posted by Dzony988 View Post
Did anyone test amp with T130-2 or T106-2 with 20-22uH?
I have an experience with T157-2, it works very well. At the same power rail ,others is get hot quickly.
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Old 19th May 2011, 05:49 PM   #1137
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Quote:
Originally Posted by Pafi View Post
And something else.

But you didn't tell enough/any informations about neither the old nor the new core. Also the load is unknown.

I don't see any sign of saturation.
5 ohms load.
inductor

How does it should look ?

The mosfets still cold.
------------------------------------
At my firts try I built 200W@4 ohms amp
Power supply = 40Vdc

It did not go to distorsion also the volume wasnŽt set to full, but the output signal started to look like the pics showed , and a sound came out like sss ssss sssSS ss.
We got almost 130W

Last edited by electroconico; 19th May 2011 at 06:08 PM.
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Old 19th May 2011, 06:02 PM   #1138
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Join Date: Apr 2010
Location: Nis, Serbia
@ Laci

How can I increase swich freq above 400KHz with your schematic.

Do I need to change value of C17, output filter and gate resistors or what?!
Thank you
Attached Images
File Type: png 320KHz from Laci.png (62.0 KB, 541 views)
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Old 19th May 2011, 06:29 PM   #1139
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Join Date: Apr 2007
Hi guys, i want try this amp, i saw the original file of this amp and the post before this saying there is a much better ways to do the pcb and some improves on the circuit.

I anyone can tellme which board i should use and modifications on the circut, i dont want protections just the amp but whit the improves that u guys just make.

Ty and sry for my english, im working on it xD
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Old 19th May 2011, 09:01 PM   #1140
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Join Date: Jun 2010
Quote:
Originally Posted by Pafi View Post
And something else.

But you didn't tell enough/any informations about neither the old nor the new core. Also the load is unknown.

I don't see any sign of saturation.

You are right , I have changed the core coil to air core and i had the same result almost at the same rate VRMS 29vrms.

So , the problem is in other place , IŽll check comparator output,Hin -Lin inputs and mosfet gate signals.

Any suggestion??

ty!
Attached Images
File Type: png nucleo de aire mismo error.png (8.3 KB, 491 views)
File Type: png senal de salida nucleo aire.png (7.7 KB, 97 views)
File Type: jpg pruebas nucleo aire.jpg (355.6 KB, 268 views)
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