Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by klubnl.pl (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id w3B03pOQ028162 for ; Wed, 11 Apr 2018 02:03:53 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1f634w-00053k-5Y for rs_out_1@blacksheep.org; Wed, 11 Apr 2018 00:53:34 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1f634v-00053b-61 for rsgb_lf_group@blacksheep.org; Wed, 11 Apr 2018 00:53:33 +0100 Received: from resqmta-ch2-11v.sys.comcast.net ([69.252.207.43]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1f634n-0004eg-Qo for rsgb_lf_group@blacksheep.org; Wed, 11 Apr 2018 00:53:31 +0100 Received: from resomta-ch2-12v.sys.comcast.net ([69.252.207.108]) by resqmta-ch2-11v.sys.comcast.net with ESMTP id 632TfM9UDOtE4632jfN4rq; Tue, 10 Apr 2018 23:51:17 +0000 X-DKIM-Result: Domain=comcast.net Result=Signature OK DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net; s=q20161114; t=1523404277; bh=GqawSBY5pT/cstW+PJ3FaxPiNqChVgHU4ECTvqS54v8=; h=Received:Received:Message-ID:From:To:Subject:Date:MIME-Version: Content-Type; b=M+66e28gVRzVRl4uv8MgtltLxwo2vTqAzBv+NDz1L+7xy5Tw1ULnXOgfYiQ/VLU5e ek+LVmVitLUYDaHWNix3N2KJJZxx8pmLd3BZw/jx3agtkK3iQdvnqbXlsvVUExQW2v DlA5g0lqVLMsYmtJ34GbtY3G9zqOZwGLo7Au7oWMa4P7pqPN+/CDHAIK+6tf4yOAxy Q4YlCiJUg6bfV5U8H+fTJSCWTSWw6hISnmRRbmQDiOOEQO6zQQJ5qnQlelq/aaBuI0 K68EMzUgJpPZXDnsycCFL4dacHjv1ziMf1+pNqd4nLQF5AOd4nuM5G4NjRWD9oYUt8 d7mhKg0VyuR7g== Received: from DELL4 ([73.4.253.141]) by resomta-ch2-12v.sys.comcast.net with SMTP id 630mfjbaFKKpS630mfVsTp; Tue, 10 Apr 2018 23:49:17 +0000 Message-ID: From: To: References: <162a4797468-1db9-bdf2@webjas-vae168.srv.aolmail.net> <4D19B3707137430CBE04857FBA5C80B1@gnat> <1b882ae9-fede-3ec4-256e-9b068d3acf99@n1bug.com> <1539CCA16B9A4092972CB000BE4C440A@DELL4> <7606DCC26D954BD1AE881D54F9F2894A@DELL4> <6832cf3c-a6e3-7b11-79dd-95f42cd9bcee@n1bug.com> <1UQRR1pNEA.1SfJSy9fbpz@optiplex980-pc> <1UQRR3nqRO.3cTL9jSmUHx@optiplex980-pc> <69686c1e-40a7-6270-eca9-b482074add94@n1bug.com> <8410601119.20180410214557@gmail.com> Date: Tue, 10 Apr 2018 19:49:15 -0400 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5512 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5512 X-CMAE-Envelope: MS4wfEy5LPeeKlKuaaeHHaRCZHdQNA0LXwswUCkhFBbXjnqxG1YghIJK8EezTgsQ+qWlbhcFZJQO3oTZbs2yK11waxG3LoeeRHxNEEwo0DWPc5Es69fafTcj sGaccOYGt0E15XVms6ESFlrS+k19qAUqq/EqFKEAHJ4a7/eAvSnDOZ9r X-Spam-Score: 0.8 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Andy Good idea on the multifilar winding. >Everyone, stop, think. Stop clutching at straws [...] Content analysis details: (0.8 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (jrusgrove[at]comcast.net) 0.0 HTML_MESSAGE BODY: HTML included in message 0.6 URIBL_SBL Contains an URL's NS IP listed in the Spamhaus SBL blocklist [URIs: www.n1bug.com] 0.1 URIBL_SBL_A Contains URL's A record listed in the Spamhaus SBL blocklist [URIs: www.n1bug.com] 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: aaa907f1cfed2776dbc1341844857d57 Subject: Re: LF: W1VD amp help - IR2110 and timing Content-Type: multipart/alternative; boundary="----=_NextPart_000_012E_01D3D105.01DB0950" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: ** X-Spam-Status: No, hits=2.4 required=5.0 tests=FORGED_MUA_OUTLOOK,HTML_20_30, HTML_FONTCOLOR_UNSAFE,HTML_MESSAGE,NO_REAL_NAME autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false This is a multi-part message in MIME format. ------=_NextPart_000_012E_01D3D105.01DB0950 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Andy Good idea on the multifilar winding. >Everyone, stop, think. Stop clutching at straws A fair number of these amplifiers have been built ... none of which = exhibit the severe ringing that this particular one does. We're = currently 'clutching at straws' to figure out what's different about = this one. =20 Jay W1VD ----- Original Message -----=20 From: Andy Talbot=20 To: LineOne=20 Sent: Tuesday, April 10, 2018 5:01 PM Subject: Re: LF: W1VD amp help - IR2110 and timing Everyone, stop, think. Stop clutching at straws Ringing like that, showing several cycles of oscillation has to be = caused by a resonance at a higher frequency than the wanted one. Resonances are caused by stray L and C. Where is stray L coming from? Leakage inductance. It's classic - seen on any SMPSU. You have to get your windings = really well coupled. A couuple of turns on a large torroid I'm sure = can't be completely leakage-free. Unless Ur were infinite. So why not = try multifilar windings ? If you want 1+1:2 turns ratio, for example, twist four conductors = together and wind the resulting set the requisite number of turns. Use = two of the strands in series for the "2" secondary, and the other two as = your 1+1 primary=20 Multifilar gives you much tighter coupling Andy G4JNT On 10 April 2018 at 21:45, Chris Wilson wrote: Hello Paul, here's a link to my prototype build, the more I think = back to bad drain waveforms the more convinced I am that the major fix = was added decoupling. I read Jay's very salient post about none = inductive probing, but for clarity my scope captures are with two X10 = probes with the hooked spring tips on, and the normal ground leads = both clipped to the driver board PCB ground plane, next to one another, = so nothing careful done there to get those captures. As we seem to be running short of ideas re the amp itself, = bar decoupling and short gate wires, what about the LPF?? I used = blue polypropylene (I think...) caps of about 1500V DC> Each section is = in its own totally sealed box, the mid toroid has two windows milled = in the box with gauze over them for a PC processor fan to blow air = across the inductor. Each outer box feeds through to the mid one via = drilled holes of about 10mm diameter with the inductor wires in = Teflon sleeving. Directly soldered. Caps are in each end box. Decoupling caps are at http://www.chriswilson.tv/decoupling.jpg they are done on the actual board of the MKII amp ;) But = functionally there was no difference. Tuesday, April 10, 2018, 9:04:45 PM, you wrote: > OK, let's switch topics a bit. > I have a serious drain circuit ringing problem that most builders > apparently don't have. Many things change all but the first peak = of > the ringing, but that first one is stubborn. It almost seems like > that first big peak is being "forced" to occur somehow. > I believe someone mentioned, though I cannot find it now, that = cross > conduction (one phase starting to switch on before the other is > completely off) would exaggerate ringing. > I've become curious as to whether the timing in my amp is correct. > No one has really commented on this aspect. My driver board is > unique and it would not be at all surprising it it has stray > capacitance in excess of most! > Here are the two gate waveforms overlaid so you can see the = crossing: > http://www.n1bug.com/gates4-wdv13.jpg > And here are the drains similarly overlaid to show the crossing: > http://www.n1bug.com/drains2-wdv13.jpg > *Is* this OK or could the timing be just a bit off? I lack the > knowledge to interpret what I am looking at. > *If* it could possibly stand some improvement, do I have control > over it? I think the 1000pf caps and 15k resistors on the IR2110 > inputs would affect this timing but I haven't been able to work = out > exactly how or what to change if I wanted to experiment: > http://w1vd.com/137-500-KWRev3.0.pdf > Paul -- Best regards, Chris mailto:dead.fets@gmail.com ------=_NextPart_000_012E_01D3D105.01DB0950 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable =EF=BB=BF
Andy
 
Good idea on the multifilar = winding.
 
>Everyone, stop, think. Stop clutching at straws
 
A fair number of these amplifiers = have been=20 built ... none of which exhibit the severe ringing that this = particular one=20 does. We're currently 'clutching at straws' to figure out = what's=20 different about this one.    
 
Jay W1VD
----- Original Message -----
From:=20 Andy=20 Talbot
To: LineOne
Sent: Tuesday, April 10, 2018 = 5:01=20 PM
Subject: Re: LF: W1VD amp help = - IR2110=20 and timing

Everyone, stop, think. Stop clutching at straws

Ringing like that, showing several cycles of oscillation has = to=20 be  caused by a resonance at a higher frequency than the wanted=20 one.
Resonances are caused by stray L and C.
Where is stray L coming from?
Leakage inductance.

It's classic - seen on any SMPSU.   You have to get = your=20 windings really well coupled.  A couuple of turns on a large = torroid I'm=20 sure can't be completely leakage-free.  Unless Ur were = infinite.  So=20 why not try multifilar windings ?

If you want 1+1:2 turns ratio, for example,  twist four = conductors=20 together and wind the resulting set the requisite number of = turns. =20  Use two of the strands in series for the "2" secondary, and the = other=20 two as your 1+1 primary 
Multifilar gives you much tighter coupling

Andy G4JNT


On 10 April 2018 at 21:45, Chris Wilson <dead.fets@gmail.com> wrote:


Hello=20 Paul, here's a link to my prototype build, the more I think = back
to bad=20 drain waveforms the more convinced I am that the major fix=20 was
added  decoupling. I read Jay's very salient post about = none=20 inductive
probing,  but  for  clarity  my = scope=20 captures are with two X10 probes
with  the  = hooked =20 spring  tips  on,  and the normal ground leads=20 both
clipped  to the driver board PCB ground plane, next to = one=20 another, so
nothing careful done there to get those=20 captures.

As  we  seem  to  be =20 running  short  of  ideas re the amp itself,=20 bar
decoupling  and  short  gate  = wires,  what=20 about the LPF?? I used blue
polypropylene  (I think...) caps = of=20 about 1500V DC> Each section is in
its  own  totally = sealed=20 box, the mid toroid has two windows milled in
the box with gauze = over=20 them for a PC processor fan to blow air across
the  = inductor. Each=20 outer box feeds through to the mid one via drilled
holes  = of =20 about  10mm  diameter  with  the  = inductor =20 wires in Teflon
sleeving. Directly soldered. Caps are in each end = box.

Decoupling caps are at http://www.chriswilson.tv/decoupling.jpg
they =20 are done on the actual board of the MKII amp ;) But = functionally
there=20 was no difference.

Tuesday, April 10, 2018, 9:04:45 PM, you=20 wrote:

> OK, let's switch topics a bit.

> I have = a=20 serious drain circuit ringing problem that most builders
> = apparently=20 don't have. Many things change all but the first peak of
> the = ringing, but that first one is stubborn. It almost seems = like
> that=20 first big peak is being "forced" to occur somehow.

> I = believe=20 someone mentioned, though I cannot find it now, that cross
>=20 conduction (one phase starting to switch on before the other = is
>=20 completely off) would exaggerate ringing.

> I've become = curious as=20 to whether the timing in my amp is correct.
> No one has = really=20 commented on this aspect. My driver board is
> unique and it = would not=20 be at all surprising it it has stray
> capacitance in excess = of=20 most!

> Here are the two gate waveforms overlaid so you = can see=20 the crossing:

> http://www.n1bug.com/gates4-wdv13.jpg

&g= t;=20 And here are the drains similarly overlaid to show the = crossing:

>=20 http://www.n1bug.com/drains2-wdv13.jpg

&= gt;=20 *Is* this OK or could the timing be just a bit off? I lack = the
>=20 knowledge to interpret what I am looking at.

> *If* it = could=20 possibly stand some improvement, do I have control
> over it? = I think=20 the 1000pf caps and 15k resistors on the IR2110
> inputs would = affect=20 this timing but I haven't been able to work out
> exactly how = or what=20 to change if I wanted to experiment:

> http://w1vd.com/137-500-KWRev3.0.pdf

>= ;=20 Paul




--
Best regards,
 Chris    =    =20                   =  =20 mailto:dead.fets@gmail.com



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