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 w3AL8lqo027660 for ; Tue, 10 Apr 2018 23:08:48 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1f60Pq-0004AF-9p for rs_out_1@blacksheep.org; Tue, 10 Apr 2018 22:02:58 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1f60Pp-0004A6-A3 for rsgb_lf_group@blacksheep.org; Tue, 10 Apr 2018 22:02:57 +0100 Received: from mail-wm0-f43.google.com ([74.125.82.43]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1f60Ph-0004Hx-V5 for rsgb_lf_group@blacksheep.org; Tue, 10 Apr 2018 22:02:56 +0100 Received: by mail-wm0-f43.google.com with SMTP id r131so10150wmb.2 for ; Tue, 10 Apr 2018 14:02:47 -0700 (PDT) X-DKIM-Result: Domain=gmail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=9m/PBCEGOuajh9Bu7zKa33f5QMzdelgSnMnKbBRDzLA=; b=phAj7D98ZTlI9yZMguIrB0+Xj46KmceV9Znh+jHYJa4WL4/O9UNUj/dNmr47OOcuAG M6x9KnyFLemZhG+hyD6RFb8Ks07/euomRnS7y7Y36tF6hsD9f62dSBFSFM7zjdNkinxy cvHz4MQjZxprKzN1z1VcsTzJo//p4MoFbQV1JeGu3zQVSrQLp7XiWkOqEF9V3JSu3VtR AA9HAW9pbNT+zSJfDztT2K1+U0kJ4NVuVCRfVoFUKNdIUz0st4HBLFCvlNdapivPUJu6 bZiiTrhi5Xb0uV26tYlk5sHrrdEUFwhr0WkpMCqgIHMb9JIo5Y0hmHhf/NNLDdKh5LGf DOmg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=9m/PBCEGOuajh9Bu7zKa33f5QMzdelgSnMnKbBRDzLA=; b=XS/NwtrloQa0ucjJRaqn53pmU2Ce32CaiQOtpGSW8Ob+/zb6ckGkIZ3Tlye7qbyiv8 h2+JO7ChvIdId0PpRFSOUpxcPfLTYDwmtFYO2xVn+T6/Dhn6T5TT/T0EI14wxZQGdaoZ T6Y3BNln5FU5GjmteL1YolNg107NKCvJNftSXym+tKsv9+rnBO5w9rkVNUF9g3iziyeH eNINhVjIgWhPAE2NP689zOE84QOfSQXiOgECEyeHwuJQqUBokmRHcxC8FXLP3Vi80aGG WdFvX2iV1y2V+Ejmv1LScX++2n3kolFSotu5GKf58V6FiQCsWwwM6lJDTJ5isr3iFgS5 G+sg== X-Gm-Message-State: ALQs6tBaaTmUH4RWJlSf9/6CPb2i9zEobKHIb9PE5u5scfm3vSMiwYnG 6PIQl9vWqIXnhFaGiVZT7iXXfvJraIDpT5rAxbgiqw== X-Google-Smtp-Source: AIpwx49MgFBaNXh28E2XiTbh4UKBPiypTPvENqi1V2CD5jCKJ4esLvOas7qr3tcZEu9XrOcld68Rjx8Ya0uhbcudoIk= X-Received: by 10.80.244.1 with SMTP id r1mr5769747edm.111.1523394107247; Tue, 10 Apr 2018 14:01:47 -0700 (PDT) MIME-Version: 1.0 Received: by 10.80.154.195 with HTTP; Tue, 10 Apr 2018 14:01:46 -0700 (PDT) In-Reply-To: <8410601119.20180410214557@gmail.com> 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> From: Andy Talbot Date: Tue, 10 Apr 2018 22:01:46 +0100 Message-ID: To: LineOne X-Spam-Score: 1.8 (+) 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: 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. [...] Content analysis details: (1.8 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (andy.g4jnt[at]gmail.com) 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 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid 1.0 FREEMAIL_REPLY From and body contain different freemails X-Scan-Signature: 052e5a7ab87161a07560b72babff3441 Subject: Re: LF: W1VD amp help - IR2110 and timing Content-Type: multipart/alternative; boundary="089e0825321c9d901a056984d4ce" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.1 required=5.0 tests=HTML_FONTCOLOR_UNSAFE, HTML_MESSAGE 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 --089e0825321c9d901a056984d4ce Content-Type: text/plain; charset="UTF-8" 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 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 > > > --089e0825321c9d901a056984d4ce Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Everyone, stop, think. Stop clutching at straws

Ringing like that, showing several cycles of oscillation=C2=A0has = to be=C2=A0 caused by a resonance at a higher frequency than the wanted one= .
Resonances are caused by stray L and C.
Where is stra= y L coming from?
Leakage inductance.

It&= #39;s classic - seen on any SMPSU.=C2=A0 =C2=A0You have to get your winding= s really well coupled.=C2=A0 A couuple of turns on a large torroid I'm = sure can't be completely leakage-free.=C2=A0 Unless Ur were infinite.= =C2=A0 So why not try multifilar windings ?

If you= want 1+1:2 turns ratio, for example,=C2=A0 twist four conductors together = and wind the resulting set the requisite number of turns.=C2=A0 =C2=A0Use t= wo of the strands in series for the "2" secondary, and the other = two as your 1+1 primary=C2=A0
Multifilar gives you much tighter c= oupling

Andy G4JNT


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


Hello Paul, here's a link to my prototype build, the more I think back<= br> to bad drain waveforms the more convinced I am that the major fix was
added=C2=A0 decoupling. I read Jay's very salient post about none induc= tive
probing,=C2=A0 but=C2=A0 for=C2=A0 clarity=C2=A0 my scope captures are with= two X10 probes
with=C2=A0 the=C2=A0 hooked=C2=A0 spring=C2=A0 tips=C2=A0 on,=C2=A0 and the= normal ground leads both
clipped=C2=A0 to the driver board PCB ground plane, next to one another, so=
nothing careful done there to get those captures.

As=C2=A0 we=C2=A0 seem=C2=A0 to=C2=A0 be=C2=A0 running=C2=A0 short=C2=A0 of= =C2=A0 ideas re the amp itself, bar
decoupling=C2=A0 and=C2=A0 short=C2=A0 gate=C2=A0 wires,=C2=A0 what about t= he LPF?? I used blue
polypropylene=C2=A0 (I think...) caps of about 1500V DC> Each section is= in
its=C2=A0 own=C2=A0 totally sealed box, the mid toroid has two windows mill= ed in
the box with gauze over them for a PC processor fan to blow air across
the=C2=A0 inductor. Each outer box feeds through to the mid one via drilled=
holes=C2=A0 of=C2=A0 about=C2=A0 10mm=C2=A0 diameter=C2=A0 with=C2=A0 the= =C2=A0 inductor=C2=A0 wires in Teflon
sleeving. Directly soldered. Caps are in each end box.

Decoupling caps are at http://www.chriswilson.tv/decoup= ling.jpg

they=C2=A0 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 o= f
> 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:<= br>
> 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 ou= t
> exactly how or what to change if I wanted to experiment:

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

> Paul




--
Best regards,
=C2=A0Chris=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 mailto:dead.fets@gmail.com



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