Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mk06.r1000.mx.aol.com (Internet Inbound) with ESMTP id 593B2380000A2; Mon, 8 Apr 2013 16:14:39 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1UPI2l-0001Km-6c for rs_out_1@blacksheep.org; Mon, 08 Apr 2013 20:47:55 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1UPI2k-0001Kd-Iq for rsgb_lf_group@blacksheep.org; Mon, 08 Apr 2013 20:47:54 +0100 Received: from mail-oa0-f54.google.com ([209.85.219.54]) by relay1.thorcom.net with esmtps (TLSv1:RC4-SHA:128) (Exim 4.77) (envelope-from ) id 1UPI2i-0000r7-9b for rsgb_lf_group@blacksheep.org; Mon, 08 Apr 2013 20:47:53 +0100 Received: by mail-oa0-f54.google.com with SMTP id n12so6552579oag.41 for ; Mon, 08 Apr 2013 12:47:29 -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=20120113; h=mime-version:x-received:in-reply-to:references:date:message-id :subject:from:to:content-type; bh=3vuxxA1fb66sSwNMriA8dVJ6iiae+007wGMR53WwmFc=; b=Td/O0iN0YWhuk7X2CnH4U+nfON+HZQ7ewtQTJz6vqwzghQXl2mnq1sWo2xFhsIFqoS XEPRzqACAuUwPdfPKhA6ZOGA/EcQd2cKR9FuKH1Pbfss+WMBmXUVmSylXzc+5+nP1Jz1 sqefiMWQLUBbd/sNFs+ZDAOLFv5wvxkyc8WuxRKgtzQbRvSHo4MBa1LSajgMwn+qhMkl lMDhHM370b5oCchHMsfyDbWnRlqZTSj+gHBm9QKrnk7/6bQ0uu3OJWY0f9ltsvCBhpYV w2z8R+0wg2dFApuae+zvlkxO+86aeV3MtmMQBEn69fTgH3Gr8RIBRLR5y2W1R4fnganS Cy1A== MIME-Version: 1.0 X-Received: by 10.182.45.231 with SMTP id q7mr16670761obm.58.1365450449816; Mon, 08 Apr 2013 12:47:29 -0700 (PDT) Received: by 10.60.135.199 with HTTP; Mon, 8 Apr 2013 12:47:29 -0700 (PDT) In-Reply-To: References: Date: Mon, 8 Apr 2013 15:47:29 -0400 Message-ID: From: Warren Ziegler To: rsgb_lf_group X-Spam-Score: -0.7 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Clemens, Thank you! Warren On Mon, Apr 8, 2013 at 3:42 PM, Clemens Paul wrote: > Hi Warren, > > I know a German OM (RF engineer) who has recently implemented a hall sensor > for overcurrent shutdown for his > home built 1KW short wave FET PA successfully. > I will ask him if he is willing to disclose his design and send it to you > if > he agrees. > > 73 > Clemens > DL4RAJ > > > > > Content analysis details: (-0.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [209.85.219.54 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (wd2xgj[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: ebcef237b0394d499a293e835099e25a Subject: Re: LF: Re: Hall Effect for Over-current shutdown? Content-Type: multipart/alternative; boundary=047d7b67785a0513ec04d9deb52a X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=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 x-aol-global-disposition: G X-AOL-SCOLL-AUTHENTICATION: mtain-mk06.r1000.mx.aol.com ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1d618a5163252f5a7f X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none --047d7b67785a0513ec04d9deb52a Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Clemens, Thank you! Warren On Mon, Apr 8, 2013 at 3:42 PM, Clemens Paul wrote: > Hi Warren, > > I know a German OM (RF engineer) who has recently implemented a hall sens= or > for overcurrent shutdown for his > home built 1KW short wave FET PA successfully. > I will ask him if he is willing to disclose his design and send it to you > if > he agrees. > > 73 > Clemens > DL4RAJ > > > > >-----Original Message----- > >From: owner-rsgb_lf_group@blacksheep.org > >[mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Warren Ziegler > >Sent: Monday, April 08, 2013 9:07 PM > >To: rsgb_lf_group > >Subject: Re: LF: Re: Hall Effect for Over-current shutdown? > > > >Hi Alan, > > > > I've modified the G0MRF amp with the M0BMU output > >configuration, I'm using a 30V supply. > >The G0MRF uses a current sense resistor to shut down the amp > >quickly in case too much current is being draw. > >I've modified the output transformer turns ratio to produce > >more power at lower supply voltages (I'm using 500V, 55a FETs). > >However with the new higher currents and with a new > >appropriate value sense resistor its developing a LOT of heat > >(12 W or so) and needs to be heat-sinked. > >I'm thinking Hall-effect might be more efficient and produce > >less heat - I'm pretty sure that others have used Hall effect > >devices to protect MOSFET amplifier and I'm looking for circuit tips. > > > >73 & Tnx! > >Warren > > > > > > > > > >On Mon, Apr 8, 2013 at 2:52 PM, Alan Melia > > wrote: > > > > > > > > Ah interesting problem Warren.... why is it > >over-current?? if it is over-current because a high voltage > >has welded/melted a short between drain and source, then the > >protection wont help ....high currents usually lead to excess > >heating ......but what is the real cause? If you really need > >DC supply protection would not a high-side current monitor be > >easier/faster??? The problem then could be there is enough > >energy stored in the PA choke to zap the FET before, or even > >if, you can disconnect the supply. > > > > OK drive fails permanently on might be a condition it > >would protect the FETs against with DC coupled drive > > > > Alan G3NYK > > > > ----- Original Message ----- > > From: Warren Ziegler > > To: rsgb_lf_group > > > > Sent: Monday, April 08, 2013 7:15 PM > > Subject: LF: Hall Effect for Over-current shutdown? > > > > Anyone using a Hall effect device for > >overcurrent sensing and shutdown in a MOSFET amplifer? > > > > > > -- > > 73 Warren K2ORS > > WD2XGJ > > WD2XSH/23 > > WE2XEB/2 > > WE2XGR/1 > > > > > > > > > > > > > >-- > >73 Warren K2ORS > > WD2XGJ > > WD2XSH/23 > > WE2XEB/2 > > WE2XGR/1 > > > > > >E-Mail ist virenfrei. > >Von AVG =FCberpr=FCft - www.avg.de > >Version: 2013.0.3272 / Virendatenbank: 3162/6232 - > >Ausgabedatum: 08.04.2013 > > > > > > > --=20 73 Warren K2ORS WD2XGJ WD2XSH/23 WE2XEB/2 WE2XGR/1 --047d7b67785a0513ec04d9deb52a Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
Clemens,
=A0 Thank you!
Warren



On Mon, Apr 8, 2013 at 3:42 PM, Clemens Paul <cpaul@gmx.net<= /a>> wrote:
Hi Warren,

I know a German OM (RF engineer) who has recently implemented a hall sensor=
for overcurrent shutdown for =A0his
home built 1KW short wave FET PA successfully.
I will ask him if he is willing to disclose his design and send it to you i= f
he agrees.

73
Clemens
DL4RAJ



>-----Original Message-----
>From: owner-rsgb_= lf_group@blacksheep.org
>[mailto:owner-rsg= b_lf_group@blacksheep.org] On Behalf Of Warren Ziegler
>Sent: Monday, April 08, 2013 9:07 PM
>To: rsgb_lf_group
>Subject: Re: LF: Re: Hall Effect for Over-current shutdown?
>
>Hi Alan,
>
> =A0 =A0I've modified the G0MRF amp with the M0BMU output
>configuration, I'm using a 30V supply.
>The G0MRF uses a current sense resistor to shut down the amp
>quickly in case too much current is being draw.
>I've modified the output transformer turns ratio to produce
>more power at lower supply voltages (I'm using 500V, 55a FETs).
>However with the new higher currents and with a new
>appropriate value sense resistor its developing a LOT of heat
>(12 W or so) and needs to be heat-sinked.
>I'm thinking Hall-effect might be more efficient and produce
>less heat - I'm pretty sure that others have used Hall effect
>devices to protect MOSFET amplifier and I'm looking for circuit tip= s.
>
>73 & Tnx!
>Warren
>
>
>
>
>On Mon, Apr 8, 2013 at 2:52 PM, Alan Melia
><alan.melia@btinternet.= com> wrote:
>
>
>
> =A0 =A0 =A0 Ah interesting problem Warren.... why is it
>over-current?? if it is over-current because a high voltage
>has welded/melted a short between drain and source, then the
>protection wont help ....high currents usually lead to excess
>heating ......but what is the real cause? If you really need
>DC supply protection would not a high-side current monitor be
>easier/faster??? The problem then could be there is enough
>energy stored in the PA choke to zap the FET before, or even
>if, you can disconnect the supply.
>
> =A0 =A0 =A0 OK drive fails permanently on might be a condition it
>would protect the FETs against with DC coupled drive
>
> =A0 =A0 =A0 Alan G3NYK
>
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 ----- Original Message -----
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 From: Warren= Ziegler <mailto:wd2xgj@gmail.com>
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 To: rsgb_lf_group
><mailto:rsgb_lf_grou= p@blacksheep.org>
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 Sent: Monday, April 08, 2013 7:15 PM
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 Subject: LF: Hall Effect for Over-current = shutdown?
>
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 Anyone using a Hall effect device for
>overcurrent sensing and shutdown in a MOSFET amplifer?
>
>
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 --
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 73 Warren K2ORS
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 WD2XGJ
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 WD2XSH/23<= br> > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 WE2XEB/2 > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 WE2XGR/1 >
>
>
>
>
>
>--
>73 Warren K2ORS
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0WD2XGJ
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0WD2XSH/23
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0WE2XEB/2
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0WE2XGR/1
>
>
>E-Mail ist virenfrei.
>Von AVG =FCberpr=FCft - www.avg.de
>Version: 2013.0.3272 / Virendatenbank: 3162/6232 -
>Ausgabedatum: 08.04.2013
>
>





--
73 Warren K2= ORS
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 WD2XGJ
=A0 =A0 =A0 =A0 =A0 =A0 = =A0 =A0 WD2XSH/23
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 WE2XEB/2
=A0 =A0 = =A0 =A0 =A0 =A0 =A0 =A0 WE2XGR/1

=A0
--047d7b67785a0513ec04d9deb52a--