X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 23 Feb 2010 14:50:16 -0500 Message-ID: X-Original-Return-Path: Received: from elasmtp-kukur.atl.sa.earthlink.net ([209.86.89.65] verified) by logan.com (CommuniGate Pro SMTP 5.3.2) with ESMTP id 4135198 for lml@lancaironline.net; Tue, 23 Feb 2010 14:01:03 -0500 Received-SPF: none receiver=logan.com; client-ip=209.86.89.65; envelope-from=colyncase@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=anGQAO4EIrQrKA4uWFnLpOtjMwj5dIK6e5kIMTovsc7ssGeWpGMOQnRv1jyJ6Xuj; h=Received:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE:X-ELNK-Trace:X-Originating-IP; Received: from [216.57.118.190] (helo=ccaselt3) by elasmtp-kukur.atl.sa.earthlink.net with esmtpa (Exim 4.67) (envelope-from ) id 1Njzzf-0001CR-8K for lml@lancaironline.net; Tue, 23 Feb 2010 14:00:28 -0500 X-Original-Message-ID: From: "Colyn Case at earthlink" X-Original-To: "Lancair Mailing List" References: Subject: Re: [LML] Re: Solid State Contactors -- SuperSwitch? X-Original-Date: Tue, 23 Feb 2010 14:00:26 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00B1_01CAB490.8CFD47E0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5843 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-ELNK-Trace: 63d5d3452847f8b1d6dd28457998182d7e972de0d01da940142f6115aa109e7c54bc4219d3276206350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 216.57.118.190 This is a multi-part message in MIME format. ------=_NextPart_000_00B1_01CAB490.8CFD47E0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable re: the ev-200. It's impressive on a number of metrics: max break = current, hold current to name a couple. It turns out they have a lower cost line, the ev-100. This does not = have the extra-low hold current feature and can't handle quite as big a load. A mix of ev-200's and ev-100's may = be appropriate for a grid. re: mechanical contactors. There is a very side range in specs and = mechanical integrity. Although I went with the ev-200 myself I suspect a very beefy white-rodgers would be less = likely to have the stuck closed behavior described below. ----- Original Message -----=20 From: marv@lancair.net=20 To: lml@lancaironline.net=20 Sent: Tuesday, February 23, 2010 9:34 AM Subject: [LML] Re: Solid State Contactors -- SuperSwitch? Posted for "John Richardson" : Hi Valin and LML =20 I have been using a prototype version of the Lamar "Super Switch" in = my 28V=20 legacy. I'm using the uni-directional version as a starter contactor. = I've=20 got about 300 hours on the plane now and this "contactor" has never = failed. I=20 must tell you that I got onto Lamar initially because of their starter = which=20 is a direct drive (no planetary gear reduction drive like the Iskra) = due to=20 the bad reports about starters that do not release the Continental = starter=20 drive adapter spring. I subsequently found out after talking to their = lead=20 engineer working on the Super Switch that it uses the new P-channel = MOSFETs (I=20 think several in parallel) as a high side switch just like a solenoid=20 contactor. (you put the contactor between the battery and the input = to the=20 starter and the other lead of the starter is internally grounded) . = Also, I=20 have had starter traditional aircraft contactors fail (on a Cessna) = where it=20 sticks closed even though you release the ignition key from the = "start"=20 position. So I figured it's time to get rid of the traditional = contactor, at=20 least when switching high current. Just as background, high current = MOSFETs=20 have always been N-channel up until just a few years ago so high side=20 switching of very low impedance loads was not very simple. Now the = P-channel=20 devices (which make high side switching simple) are almost as good and = rated=20 at incredible high peak current. We'll see how well they hold up. I = test it=20 each time I start the engine. I"m flying the engineer's second = prototype=20 switch and gave them early feedback. I learned that Cirrus was = thinking about=20 using several of these switches in a centralized switching matrix to = control=20 all the high current circuits like flaps, landing lights etc. Don't = know if=20 that happened. =20 =20 I have chosen to limit my exposure to this new technology and do not = use the=20 bi-directional super switch in the master contactor application. One = is=20 enough. However, there are, I think, better solutions than just using = the=20 standard aircraft solenoid contactor. I decided to use the Tyco = EV-200 high=20 current relay as a master contactor. There has been some discussion = on the=20 LML about the EV-200. It is more expensive than the standard aircraft = solenoid, Tyco has a very complete spec sheet on the unit, and these = specs are=20 great. Also, the master contactor usually does not have to actually = switch=20 (make or break) high current like a starter contactor. Plus the = EV-200 has a=20 spec for number of on/off cycles. When not switching high current, = this spec=20 is very high. I forget the actual number, but I could not find = meaningful=20 specs for the typical aircraft contactor. One last plus for the = EV-200....it=20 draws only about 70 mA hold current. Weight is 1 lb. Bob Nuckolls = was going=20 to analyze one about a year ago but I've not seen that report. =20 =20 Hope this helps.=20 =20 John Richardson Legacy N16DX =20 ----- Original Message -----=20 From: Valin & Allyson Thorn=20 To: lml@lancaironline.net=20 Sent: Monday, February 22, 2010 5:09 AM Subject: [LML] Solid State Contactors -- SuperSwitch? =20 =20 Hey LML gang,=20 =20 =20 =20 Has anyone had experience with these Lamar Technologies solid state=20 contactors (see info from ACS below)? I know they're expensive - but, = we're=20 already in that category of contactor with the need for 28V high = continuous=20 current contactors (100 A alternator, all electric A/C). We already = have=20 these very nice Blue Marine high capacity contactors that are = hermetically=20 ...snip... -- For archives and unsub = http://mail.lancaironline.net:81/lists/lml/List.html ------=_NextPart_000_00B1_01CAB490.8CFD47E0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
re: the ev-200.   It's = impressive on a=20 number of metrics:   max break current, hold current to name a = couple.
It turns out they have a lower cost = line, the=20 ev-100.  This does not have the extra-low hold current feature=20 and
can't handle quite as big a = load.   A mix=20 of ev-200's and ev-100's may be appropriate for a grid.
 
re: mechanical = contactors.    There=20 is a very side range in specs and mechanical integrity.   = Although I=20 went with
the ev-200 myself I suspect a very = beefy=20 white-rodgers would be less likely to have the stuck closed behavior = described=20 below.
----- Original Message -----
From:=20 marv@lancair.net=20
Sent: Tuesday, February 23, = 2010 9:34=20 AM
Subject: [LML] Re: Solid State = Contactors=20 -- SuperSwitch?

Posted for "John = Richardson"=20 <n16dx@comcast.net>:

 = ;Hi=20 Valin and LML
 
 I have been using a prototype version = of the=20 Lamar "Super Switch" in my 28V
legacy.  I'm using the=20 uni-directional version as a starter contactor.  I've =
got about=20 300 hours on the plane now and this "contactor" has never = failed.  I=20
must tell you that I got onto Lamar initially because of their = starter=20 which
is a direct drive (no planetary gear reduction drive like = the Iskra)=20 due to
the bad reports about starters that do not release the = Continental=20 starter
drive adapter spring.  I subsequently found out = after=20 talking to their lead
engineer working on the Super Switch that it = uses=20 the new P-channel MOSFETs (I
think several in parallel) as a high = side=20 switch just like a solenoid
contactor.  (you put the = contactor=20 between the battery and the input to the
starter and the other = lead of the=20 starter is internally grounded) .  Also, I
have had = starter=20 traditional aircraft contactors fail (on a Cessna) where it
sticks = closed=20 even though you release the ignition key from the "start"=20
position.  So I figured it's time to get rid of the = traditional=20 contactor, at
least when switching high current.  Just = as=20 background, high current MOSFETs
have always been N-channel up = until just=20 a few years ago so high side
switching of very low impedance loads = was not=20 very simple.  Now the P-channel
devices (which make high = side=20 switching simple) are almost as good and rated
at incredible high = peak=20 current.  We'll see how well they hold up. I test it =
each time I=20 start the engine.  I"m flying the engineer's second = prototype=20
switch and gave them early feedback.  I learned that = Cirrus was=20 thinking about
using several of these switches in a centralized = switching=20 matrix to control
all the high current circuits like flaps, = landing lights=20 etc.  Don't know if
that=20 happened.  
 
 I have chosen to limit my = exposure to=20 this new technology and do not use the
bi-directional super switch = in the=20 master contactor application.  One is=20
enough.  However, there are, I think, better solutions = than just=20 using the
standard aircraft solenoid contactor.  I = decided to=20 use the Tyco EV-200 high
current relay as a master=20 contactor.  There has been some discussion on the
LML = about the=20 EV-200.  It is more expensive than the standard aircraft=20
solenoid, Tyco has a very complete spec sheet on the unit, and = these specs=20 are
great.  Also, the master contactor usually does not = have to=20 actually switch
(make or break) high current like a starter=20 contactor.  Plus the EV-200 has a
spec for number of = on/off=20 cycles.  When not switching high current, this spec
is = very=20 high.   I forget the actual number, but I could not find = meaningful=20
specs for the typical aircraft contactor.  One last plus = for the=20 EV-200....it
draws only about 70 mA hold = current.  Weight is 1=20 lb.  Bob Nuckolls was going
to analyze one about a year = ago but=20 I've not seen that report.  
 
 Hope this = helps.=20
 
 John Richardson
 Legacy N16DX
  =
-----=20 Original Message -----
  From: Valin & Allyson Thorn =
 =20 To: lml@lancaironline.net
  Sent: Monday, February 22, 2010 = 5:09=20 AM
  Subject: [LML] Solid State Contactors --=20 SuperSwitch?
 
 
  Hey LML gang,=20
 
   
 
  Has anyone had = experience=20 with these Lamar Technologies solid state
contactors (see info = from ACS=20 below)?  I know they're expensive - but, we're
already = in that=20 category of contactor with the need for 28V high continuous =
current=20 contactors (100 A alternator, all electric A/C).  We already = have=20
these very nice Blue Marine high capacity contactors that are = hermetically=20
...snip...

--

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