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Old 31st August 2006, 11:04 AM   #491
Tyimo is offline Tyimo  Hungary
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Hi Mads!

Could you tell me the voltage values in your BOZ? I mean the measured values on the Gate and Drain? (and on the Source too.)
A friend of me has some problem and it would be help for him.
Maybe He will write here him self too.

And one question from me: could you draw or show me a cascoded source follower circuit? Just to see how is it looks like. I have never seen any....
Maybe it would be a good starting point to build something with my power Jfets.

Greets:

Tyimo
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Old 31st August 2006, 04:24 PM   #492
ruferto is offline ruferto  Portugal
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Default 36v 4A

My first post.
Hi
give me your opinion.

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Old 31st August 2006, 06:31 PM   #493
Mad_K is offline Mad_K  Norway
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Quote:
Originally posted by Tyimo

Could you tell me the voltage values in your BOZ? I mean the measured values on the Gate and Drain? (and on the Source too.)

The voltage values is in the schematic (attached) About 7,5V on the gate and 3,5V on the source actually. Adjusted to 25V on the Drain for a clean +/-20V output swing.
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Old 31st August 2006, 06:36 PM   #494
Mad_K is offline Mad_K  Norway
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Quote:
Originally posted by Tyimo
Hi Mads!


And one question from me: could you draw or show me a cascoded source follower circuit? Just to see how is it looks like. I have never seen any....
Maybe it would be a good starting point to build something with my power Jfets.

Greets:

Tyimo
From Nelson's cascode article, Fig.7b
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Old 31st August 2006, 06:44 PM   #495
Mad_K is offline Mad_K  Norway
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Default Re: 36v 4A

Quote:
Originally posted by ruferto
My first post.
Hi
give me your opinion.


Yes, that's how you paralell mosfets If you use the IRFP250 I don't think you need it though..
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Old 1st September 2006, 12:53 AM   #496
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Quote:
36v 4A Post #492
My first post.
Hi
give me your opinion.
You may run into problems, because the upper MosFets wont nessesarily share the current equally. You might have to give them a source-resistor each.
Thorsten
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Old 1st September 2006, 02:12 PM   #497
Tyimo is offline Tyimo  Hungary
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Thanks Mads!

I will invitate here my friend with his BOZ problem.

Tyimo
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Old 3rd September 2006, 01:59 PM   #498
ACK2005 is offline ACK2005  Taiwan
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Default driver stage

Hi

I'm thinking of adding a driver stage for SEWA.

The plan is to combine BOZ preamp and the SEWA
by removing some parts near the connection.

That is, removing output capacitor of BOZ (which is mod to have 15.5V output DC voltage),
and removing input bias network for SEWA (R1,R2,R3,R9,R10,C2...).
Directly couple the input signal to Q1's G Pin

Any comment for this?
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Old 3rd September 2006, 02:16 PM   #499
Ryssen is offline Ryssen  Sweden
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Maybee this could be sommething:Hybrid Aikido-ish gain stage
I thougt of using 6c45,but changed my mind am going to try with a CF and a ECC86 before it..
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Old 4th September 2006, 05:55 AM   #500
Mad_K is offline Mad_K  Norway
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Default Re: driver stage

Quote:
Originally posted by ACK2005
Hi

I'm thinking of adding a driver stage for SEWA.

The plan is to combine BOZ preamp and the SEWA
by removing some parts near the connection.

That is, removing output capacitor of BOZ (which is mod to have 15.5V output DC voltage),
and removing input bias network for SEWA (R1,R2,R3,R9,R10,C2...).
Directly couple the input signal to Q1's G Pin

Any comment for this?

This will work quite nice for a stock SEWA I have thought about it, but since I am continously swiching gear, I haven't bothered
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