From: Dwayne Reid <dwayner@planet.eon.net>
To: Microcontroller discussion list - Public. <piclist@mit.edu>
Sender: "piclist-bounces@mit.edu" <piclist-bounces@mit.edu>
Date: Wed, 18 Aug 2021 14:38:27 -0700
Subject: Re: [EE] off the shelf TRIAC module?
Thread-Topic: [EE] off the shelf TRIAC module?
Thread-Index: AdeUerM1dG2WU6pJSYGPRa/fSJzYSg==
Message-ID: <611d7dd3.1c69fb81.7db94.3488@mx.google.com>
References:
 <CAOFvGD4fmE-dcN+T05VsdsP=qdZQ8pZfrckxdB=zf-WoyxG2Xw@mail.gmail.com>
	<AllrwM0JYB70t6ixwBUqvCrU3hAvlac2lqK017Qy5w11NpaD6bII3hbMzL1YahxrflpXdwink86Wpk8gkWR1IrB3E6P2pGFk2Epn4uOzRoc=@protonmail.com>
	<CAOFvGD6g54zfgBHn5SCQdbFSsBN5T+FsUpcgDf+j5CwDKF0foA@mail.gmail.com>
	<611d6547.1c69fb81.3600f.2722@mx.google.com>
	<CAE8uMMqk749EXgS2mtTon6y1HMDC2Czmq7quqrj-GHqcf58v1g@mail.gmail.com>
In-Reply-To: <CAE8uMMqk749EXgS2mtTon6y1HMDC2Czmq7quqrj-GHqcf58v1g@mail.g
	mail.com>
Reply-To: Microcontroller discussion list - Public. <piclist@mit.edu>
Accept-Language: en-US
X-MS-Exchange-Organization-SenderIdResult: Pass
X-MS-Exchange-Organization-PRD: mit.edu
X-MS-TNEF-Correlator:
received-spf: Pass (protection.outlook.com: domain of planet.eon.net
	designates 209.85.216.42 as permitted sender)
	receiver=protection.outlook.com; client-ip=209.85.216.42;
	helo=mail-pj1-f42.google.com;
dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed;	d=planet.eon.net;
 s=google;
	h=message-id:date:to:from:subject:in-reply-to:references:mime-version;
 	bh=fk0bDL0eKiwa5pk6Ydq34kGSqLQ9IdDjLmv3an8Hj9I=;
	b=f/Voy8s9GuEqH8a6kcEW1Dr3mprNwIavh6rdN84nRT6Evh3ClloAnwR4JMbYldMuRy
	Fl8YqiE6eRfS+brZwDI+kJfnJrZM6F0yw6fVRL5XfaLPJVDznNUU8MIjU9vQJDPy18GM
	Ond3+TcoCBOk2i1Olc3ig4/8oR1hpYuJnsqJ5gbGIZAdoJDxWVSKSeXF7ZXfH0iQ49Qc
	1MqUT0Lu6BbtgIzCNxD57W9EUSZX7x6LZprmVDDessfX8yAf6woyXzksnYMRBa2AX6K0
	c37lItXDELRYA/ZU24GCjof3VeI7yxpLY215LtILLF01d85T9vxzphiLcJfuuxIK6GBQ	0ixA==
authentication-results: spf=pass (sender IP is 209.85.216.42)
	smtp.mailfrom=planet.eon.net; mit.edu;	dkim=pass (signature was verified)
	header.d=planet.eon.net;mit.edu; dmarc=bestguesspass action=none
	header.from=planet.eon.net;
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-received: by 2002:a17:90b:2311:: with SMTP id
	mt17mr11057379pjb.201.1629322708221; 	Wed, 18 Aug 2021 14:38:28 -0700 (PDT)
x-topics: [EE]
x-content-filtered-by: Mailman/MimeDel 2.1.6
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0

Hi there, Sean.

You expressed it better than I did.  Yes: you must choose a SSR that=20
allows random fire if you want to do phase control.

Some of the PID controllers that we use allow analog voltage control=20
input (usually 0-10 Vdc) and provide the phase control output.  You=20
can also get PID modules that are intended for integral-cycle=20
control, where you would use a SSR with zero-cross switching.

So many possibilities!

Do note that it is easy to build a simple controller that takes an=20
analog control signal and generates a phase-control signal that can=20
drive either a TRIAC or random-fire SSR.  This is something that we=20
used to do a couple of decades ago.

dwayne


At 02:07 PM 8/18/2021, Sean Breheny wrote:
>Dwayne,
>
>You said "Note that you must choose
>a SSR that allows phase control (as opposed to one that has internal
>zero-cross detection)." Are you talking about the type of turn-ON criterio=
n
>(random fire vs zero-voltage switching)? Because all triacs turn OFF on
>zero-crossing (of the current).
>
>It also sounded to me like the original poster was looking for, not a
>thermostat, but a module which accepted an analog input which indicated th=
e
>% duty and which automatically converted this to a "time to fire" the tria=
c
>internally.  If that is indeed what he wants it is important to note that
>phase control isn't quite like PWM. It is inherently nonlinear in its %
>duty to effective output voltage (or average power) because the majority o=
f
>the power for a resistive load is near the peak of the sinusoid.
>
>Sean
>
>
>On Wed, Aug 18, 2021 at 3:56 PM Dwayne Reid <dwayner@planet.eon.net> wrote=
:
>
> > Hi there, Jason.
> >
> > We use a variety of 1/16 DIN PID temperature controllers.  Although
> > the units we use have a 4-20mA output, they are also available with
> > both relay (on-off) control as well as phase control output suitable
> > for driving a standard Solid State Relay.  Note that you must choose
> > a SSR that allows phase control (as opposed to one that has internal
> > zero-cross detection).
> >
> > dwayne
> >
> >
> > At 05:37 AM 8/18/2021, Jason White wrote:
> > >Yeah, you are right. I suppose most applications would just implement
> > >control signal synchronization with respect to mains in a microprocess=
or.
> > >
> > >For some reason, I was picturing a self contained module that took an
> > >analog control signal in - a glorified light dimmer intended to be wir=
ed
> > up
> > >for industrial use cases (eg. fast cycle by cycle control of power
> > >commanded by a 0-10V output from a PID module or similar)
> > >
> > >Jason White
> >
> >
> > --
> > Dwayne Reid   <dwayner@planet.eon.net>
> > Trinity Electronics Systems Ltd    Edmonton, AB, CANADA
> > 780-489-3199 voice   780-487-6397 fax   888-489-3199 Toll Free
> > www.trinity-electronics.com
> > Custom Electronics Design and Manufacturing
> > --
> > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
> > View/change your membership options at
> > http://mailman.mit.edu/mailman/listinfo/piclist
> >
>--
>http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
>View/change your membership options at
>http://mailman.mit.edu/mailman/listinfo/piclist


--=20
Dwayne Reid   <dwayner@planet.eon.net>
Trinity Electronics Systems Ltd    Edmonton, AB, CANADA
780-489-3199 voice   780-487-6397 fax   888-489-3199 Toll Free
www.trinity-electronics.com
Custom Electronics Design and Manufacturing
--=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
.