From: Bob Blick <bobblick@outlook.com>
To: Microcontroller discussion list - Public. <piclist@mit.edu>
Sender: "piclist-bounces@mit.edu" <piclist-bounces@mit.edu>
Date: Tue, 28 Apr 2020 11:26:21 -0700
Subject: Re: [EE] Seeking audio relay advice
Thread-Topic: [EE] Seeking audio relay advice
Thread-Index: AQHWGqV4XKhTk7oRR0SfY0fpjNMNP6iJmdgAgAFK9oCAA/WaXA==
Message-ID:
 <BYAPR02MB4055F238BACCF32F82DC835ADCAC0@BYAPR02MB4055.namprd02.prod.outlook.com>
References:
 <BYAPR02MB40557004C1D52433FE3C71DDDCD10@BYAPR02MB4055.namprd02.prod.outlook.com>
	<CAKsZx=3MpQ0gEO7k3eW8b_qJ-XJxKrshggNirZMYSpeLFWos=w@mail.gmail.com>,
	<8a833047-7b51-5866-e397-2cfed473973b@triad.rr.com>
In-Reply-To: <8a833047-7b51-5866-e397-2cfed473973b@triad.rr.com>
Reply-To: Microcontroller discussion list - Public. <piclist@mit.edu>
Accept-Language: en-US
Content-Language: en-US
X-MS-Exchange-Organization-SenderIdResult: Pass
X-MS-Exchange-Organization-PRD: mit.edu
X-MS-TNEF-Correlator:
acceptlanguage: en-US
received-spf: Pass (protection.outlook.com: domain of outlook.com designates
	40.92.19.72 as permitted sender) receiver=protection.outlook.com;
	client-ip=40.92.19.72;	helo=NAM11-DM6-obe.outbound.protection.outlook.com; 
dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=outlook.com;
	s=selector1;
	h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck;
	bh=7m9BBMqrMgdkKnxidwsjaq6BEbrVRzqhDqLiWaJKtFc=;
	b=uEhE1rmbavaiOkwShKkSJ3wrpk1ykuAU2S1Pu6DIEW334ZBtTdjXbP2QAqD/nn+ppbLSpIhIXXbizntuHsdrFrqSpHOWGeoI1yZID5/YieDILkhjPz+HzAr6mSjWPYoxaZ3zW/ANHkIGyohK2TOVtFPBkanpSvVVOyP8EPmGOWYicvryqTFlEOb+MwzATrXUk5ut12NL2kw1T1WylPbiaaPQX0fv8nnz7xEqBjDFp4zAZwJxmhQ1EnDR8fabrf9Ka8URRp7VYwel+CxniAbPlHYfzXiM8KUDWs97JuCtcwCV5Bl6WxytB625gfRfuHbumbs4Ed2XuAv1/L1MEkCmfw==
authentication-results: spf=pass (sender IP is 40.92.19.72)
	smtp.mailfrom=outlook.com; mit.edu; dkim=pass (signature was verified)
	header.d=outlook.com;mit.edu; dmarc=pass action=none
	header.from=outlook.com;compauth=pass reason=100
errors-to: piclist-bounces@mit.edu
list-id: "Microcontroller discussion list - Public." <piclist.mit.edu>
list-post: <mailto:piclist@mit.edu>
x-beenthere: piclist@mit.edu
x-mailman-version: 2.1.6
x-topics: [EE]
x-mime-autoconverted: from quoted-printable to 8bit by PCH.mit.edu id
	03SIQp2m000910
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0

Thanks everyone who replied and for the suggestions. I decided to take the =
chance and for $26 I have 20 HB2E-DC24V relays coming from an Aliexpress ve=
ndor. Although I'm sure what will show up will be relays, whether they are =
counterfeit or used is unknown at this time. The picture and description se=
em correct.

As to the question about the failure mode, it's a contact issue, and the sy=
mptoms are distortion, noise, and signal dropping out. Cycling the tape mon=
itor and input selectors clears it up for an annoyingly short time. When I =
originally got the unit I popped the tops off the relays(this unit has the =
original Omron unsealed relays) and squirted Cramolin, that worked for a mo=
nth or so.

This is a preamplifier, so the signals are all low level audio under 2 volt=
s AC, and very low current. So it's the textbook low current dry contact pr=
oblem.

I love the idea of hacking the relays apart and putting reed switches into =
the the original magnetic structure. Maybe I'd try it if I didn't have to d=
o it for 13 relays, each requiring two SPDT reed switches!

In 2 months when the relays finally arrive from China I'll post a reply wit=
h what showed up and if they work.=20

Cheerful regards, Bob

________________________________________
From: piclist-bounces@mit.edu <piclist-bounces@mit.edu> on behalf of John F=
errell=20
Sent: Saturday, April 25, 2020 10:39 PM
To: piclist@mit.edu
Subject: Re: [EE] Seeking audio relay advice


On 4/25/2020 5:54 AM, Forrest Christian (List Account) wrote:
> the real question is what is the
> failure mode on the relays.



--=20
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.