FORUM ON BEER, HOMEBREWING, AND RELATED ISSUES
Digest Janitor: pbabcock at hbd.org
***************************************************************
TODAY'S HOME BREW DIGEST BROUGHT TO YOU BY:
Logic, Inc. - Makers of Straight A Cleanser
www.ecologiccleansers.com
Support those who support you! Visit our sponsor's site!
********** Also visit http://hbd.org/hbdsponsors.html *********
DONATE to the Home Brew Digest. Home Brew Digest, Inc. is a
501(c)3 not-for-profit organization under IRS rules (see the
FAQ at http://hbd.org for details of this status). Donations
can be made by check to Home Brew Digest mailed to:
HBD Server Fund
PO Box 871309
Canton Township, MI 48187-6309
or by paypal to address serverfund@hbd.org. DONATIONS of $250
or more will be provided with receipts. SPONSORSHIPS of any
amount are considered paid advertisement, and may be deductible
under IRS rules as a business expense. Please consult with your
tax professional, then see http://hbd.org for available
sponsorship opportunities.
***************************************************************
Contents:
PID Control Tuning ("Devonna Dieterle")
* * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* Beer is our obsession and we're late for therapy! *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * *
NOTE: With the economy as it is, the HBD is struggling to
meet its meager operating expenses of approximately $3500
per year. If less than half of those currently directly
subscribed to the HBD sent in a mere $5.00, the HBD would
be able to easily meet its annual expenses, with room to
spare for next year. Please consider it.
Financial Projection As of 03 March 2012
*** Condition: Guarded ***
501(c)3 revoked in process of retroactive reinstatement.
See Site News on http://hbd.org for details and progress.
Projected 2012 Budget $3191.79
Expended against projection $ 721.78
Unplanned expenditures $ 79.98
Projected Excess/(Shortfall) ($ 725.01)
As always, donors and donations are publicly acknowledged
and accounted for on the HBD web page. Thank you
Send articles for __publication_only__ to post@hbd.org
If your e-mail account is being deleted, please unsubscribe first!!
To SUBSCRIBE or UNSUBSCRIBE send an e-mail message with the word
"subscribe" or "unsubscribe" to request@hbd.org FROM THE E-MAIL
ACCOUNT YOU WISH TO HAVE SUBSCRIBED OR UNSUBSCRIBED!!!**
IF YOU HAVE SPAM-PROOFED your e-mail address, you cannot subscribe to
the digest as we cannot reach you. We will not correct your address
for the automation - that's your job.
HAVING TROUBLE posting, subscribing or unsusubscribing? See the HBD FAQ at
http://hbd.org.
LOOKING TO BUY OR SELL USED EQUIPMENT? Please do not post about it here. Go
instead to http://homebrewfleamarket.com and post a free ad there.
The HBD is a copyrighted document. The compilation is copyright
HBD.ORG. Individual postings are copyright by their authors. ASK
before reproducing and you'll rarely have trouble. Digest content
cannot be reproduced by any means for sale or profit.
More information is available by sending the word "info" to
req@hbd.org or read the HBD FAQ at http://hbd.org.
JANITORs on duty: Pat Babcock (pbabcock at hbd dot org), Jason Henning,
Spencer Thomas, and Bill Pierce
----------------------------------------------------------------------
Date: Thu, 8 Mar 2012 07:58:49 -0500
From: "Devonna Dieterle" <djdieterle at hughes.net>
Subject: PID Control Tuning
I have my controllers set to simple on/off control. It's difficult to get
precise pid control without a way to vary the output. With gas, the burner
would have to be modulated in some way, either by infinite control of the
gas orifice flow or by controlling the air input and a zero governor
regulator that matches the gas flow to air. For electric, pwm control of the
element would be the simplest method. Turning a heating element or a burner
on and off via a pid algorithm is not utilizing anything more than the
proportional element and that is on/off control. There is no way to get to
zero error without an infinitely variable output that can respond to the
integral and derivative tuning parameters. So if you looking to build a
system, a controller capable of pid control would be overkill unless the
design incorporates a method of infinitely controlling the output. A on/off
controller with a narrow deadband would work fine.
------------------------------
End of HOMEBREW Digest #5911, 03/08/12
*************************************
-------
