X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 03 May 2012 13:20:51 -0400 Message-ID: X-Original-Return-Path: Received: from mail-yw0-f52.google.com ([209.85.213.52] verified) by logan.com (CommuniGate Pro SMTP 5.4.5) with ESMTPS id 5521066 for lml@lancaironline.net; Thu, 03 May 2012 10:38:38 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.213.52; envelope-from=pjdmiller@gmail.com Received: by yhpp61 with SMTP id p61so2311407yhp.25 for ; Thu, 03 May 2012 07:38:03 -0700 (PDT) Received: by 10.236.190.39 with SMTP id d27mr3197683yhn.57.1336055883220; Thu, 03 May 2012 07:38:03 -0700 (PDT) X-Original-Return-Path: Received: from [192.168.15.103] ([67.8.30.163]) by mx.google.com with ESMTPS id d25sm24372453yhe.4.2012.05.03.07.38.01 (version=TLSv1/SSLv3 cipher=OTHER); Thu, 03 May 2012 07:38:02 -0700 (PDT) From: Paul Miller Mime-Version: 1.0 (Apple Message framework v1084) Content-Type: multipart/alternative; boundary=Apple-Mail-20--881089130 Subject: Re: [LML] Re: Contactors vs Solid State Relays X-Original-Date: Thu, 3 May 2012 10:37:59 -0400 In-Reply-To: X-Original-To: "Lancair Mailing List" References: X-Original-Message-Id: X-Mailer: Apple Mail (2.1084) --Apple-Mail-20--881089130 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=windows-1252 Bill: I'd probably test the thing on the bench with cycles and measure = resistance and temperature to get an idea of whether this thing is going = to be acceptable under repeated cycles. Maybe simulate some loads with = lights or a DC motor. With my NOS plugs, which have zero bearing on this issue, I put one in = to test EGT versus the others then went to 6 and then 12 plugs after = seeing no problems. The preservative in the plugs is truly wonderful as = they look brand new. On 2012-05-03, at 8:28 AM, Bill Wade wrote: > Thanks Paul- > I=92m of the same vintage as the relay but = considerably more failure prone and less predictable- probably the = weakest link in the whole plane. > =20 > I=92ve had some experience with antique vehicles so I imagine the = lacquer on the windings and insulation materials would still be good- = I=92m curious about the resistance readings. I have a very basic = education from studying The AeroElectric Connection 15 years ago so I = hope to learn more. > =20 > I=92m guessing the Leach has more windings of finer wire. Would that = make it more likely to overheat than the Lancair unit? Does it suggest = anything about the intended applications? > =20 > Thanks- Bill Wade > =20 > =20 > From: Paul Miller > Sent: Wednesday, May 02, 2012 4:32 PM > To: lml@lancaironline.net > Subject: [LML] Re: Contactors vs Solid State Relays > =20 > Well, Bill, using 1960's NOS parts for a modern airplane? That's = about the dumbest idea I've heard today. > =20 > Paul > Legacy > Spruce Creek > (P.S. I'm using a dozen 1961 NOS spark plugs and the Legacy purrs = much better than my mega-ohm'd resistance chumpions so good luck as I'm = thinking your relay is well preserved and well built). =20 > On 2012-05-02, at 3:15 PM, Bill Wade wrote: >=20 >> =20 >> Aircraft Spruce carries a solid-state =93Superswitch=94 contactor = from Lamar Technologies. Has anyone used these? >> =20 >> FWIW there are a number of NOS 24V 50A Leach contactors for sale on = Ebay. I got a few with the idea of replacing the hydraulic pump relay = supplied by Lancair. They arrived in sealed original packaging- no date = of manufacture but my guess is 50=92s or 60=92s. The exposed insulation = appears to be sound and the units function properly. >> =20 >> The Leach unit weighs 8.12 oz., about 5 oz. less than the Lancair = style and the windings measure 152.7 Ohms vs. 62.7. The pump draws about = 30A at system pressure according to the Oildyne chart. Comments? >> =20 >> Thanks- Bill Wade >=20 > =20 --Apple-Mail-20--881089130 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=windows-1252 Bill: = I'd probably test the thing on the bench with cycles and measure = resistance and temperature to get an idea of whether this thing is going = to be acceptable under repeated cycles.  Maybe simulate some loads = with lights or a DC motor.

With my NOS plugs, which = have zero bearing on this issue, I put one in to test EGT versus the = others then went to 6 and then 12 plugs after seeing no problems. =  The preservative in the plugs is truly wonderful as they look = brand new.
On 2012-05-03, at 8:28 AM, Bill Wade = wrote:

Thanks Paul-
=
           &nb= sp;        =20 I=92m of the same vintage as the relay but considerably more failure = prone and=20 less predictable- probably the weakest link in the whole plane.
 
  I=92ve had some experience with antique vehicles so I = imagine the=20 lacquer on the windings and insulation materials would still be good- = I=92m=20 curious about the resistance readings. I have a very basic education = from=20 studying The AeroElectric Connection 15 years ago so I hope to learn = more.
 
  I=92m guessing the Leach has more windings of finer wire. = Would that=20 make it more likely to overheat than the Lancair unit? Does it suggest = anything=20 about the intended applications?
 
  Thanks- Bill Wade
 
 
Sent: Wednesday, May 02, 2012 4:32 PM
Subject: [LML] Re: Contactors vs Solid State=20 Relays
 
Well,=20 Bill, using 1960's NOS parts for a modern airplane?  That's about = the=20 dumbest idea I've heard today.=20
 
Paul
Legacy
Spruce Creek
(P.S.  I'm using a dozen 1961 NOS spark plugs and the Legacy = purrs=20 much better than my mega-ohm'd resistance chumpions so good luck as I'm = thinking=20 your relay is well preserved and well built). 
On 2012-05-02, at 3:15 PM, Bill Wade wrote:

 
  Aircraft=20 Spruce carries a solid-state =93Superswitch=94 contactor from Lamar = Technologies.=20 Has anyone used these?
 
  FWIW there are=20 a number of NOS 24V 50A Leach contactors for sale on Ebay. I got a few = with=20 the idea of replacing the hydraulic pump relay supplied by Lancair. = They=20 arrived in sealed original packaging- no date of manufacture but my = guess is=20 50=92s or 60=92s. The exposed insulation appears to be sound and the = units=20 function properly.
 
  The Leach unit=20 weighs 8.12 oz., about 5 oz. less than the Lancair style and the = windings=20 measure 152.7 Ohms vs. 62.7. The pump draws about 30A at system = pressure=20 according to the Oildyne chart. Comments?
 
  Thanks- Bill=20 Wade
 

= --Apple-Mail-20--881089130--