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Date: Thu, 6 Jan 2011 09:29:51 +0000
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From: Andy Talbot <andy.g4jnt@gmail.com>
To: rsgb_lf_group@blacksheep.org
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Subject: LF: 500kHz Classe-E
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As I have all the bits available as surplus junk on the shelves, thought I
would put together a QRO class-E  PA based around Alan's spreadsheet, (with
mod for matching built in).
But before comitting to any particular power level / supply voltgage
combination thought I'd ask what others have reliably achieved with a
similar setup.

Starting parameters :
   Supply voltage anything from 28 - 55V adjustable.  25 A max
   PA device  - IRFP452 (have a small handful, so can allow a few to go
pop)  Rated 500V,   0.4 Rdson, 14A,  190 Watts
   Drive, accurate 50% square wave from ICL7667
   Resonant Inductor -  air wound with 2mm Litz wire.

I reckon that at 55V 500 Watts might be a value to aim for with a single
device, with the option to back off by lowering Vsupply.
But before committing to winding inductors and making parallel combination
of high voltage caps, does anyone have any practical experience?   Am I
aiming for too high a power perhaps.

Andy
www.g4jnt.com

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<div>As I have all the bits available as surplus junk on the shelves, thou=
ght I would put together a QRO class-E=A0 PA based around Alan&#39;s sprea=
dsheet, (with mod for=A0matching built in).</div>
<div>But before comitting to any particular power level / supply voltgage=
 combination thought I&#39;d ask what others have reliably achieved with=
 a similar setup.</div>
<div>=A0</div>
<div>Starting=A0parameters :</div>
<div>=A0=A0 Supply voltage anything from 28 - 55V adjustable.=A0 25 A max<=
/div>
<div>=A0=A0 PA device=A0 - IRFP452 (have a small handful, so can allow a=
 few to go pop)=A0 Rated 500V,=A0=A0 0.4 Rdson, 14A, =A0190 Watts</div>
<div>=A0=A0 Drive, accurate 50% square wave from ICL7667</div>
<div>=A0=A0 Resonant Inductor - =A0air wound=A0with 2mm Litz wire.</div>
<div>=A0</div>
<div>I reckon that at 55V 500 Watts might be a value to aim for with a sin=
gle device, with the option to back off by lowering Vsupply.</div>
<div>But before committing=A0to winding inductors and making parallel comb=
ination of high voltage caps, does anyone have any practical experience?=
=A0=A0 Am=A0I aiming for too high a power perhaps.</div>
<div>=A0</div>
<div>Andy</div>
<div><a href=3D"http://www.g4jnt.com/">www.g4jnt.com</a></div>
<div>=A0</div>

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