DIYAPASON-L Digest #891 - Sunday, September 28, 2003
 
Re: PC Based Relay System
  by "Larry Chace" <RLC1@etnainstruments.com>
Re: Relay Systems
  by "Larry Chace" <RLC1@etnainstruments.com>
Re: [Residence Organs]  Re: PC Based Relay System
  by "Bob Loesch" <rrloesch@jps.net>
Re: [Residence Organs]  Relay  MISS-INFORMATION for "shoppers"
  by "Peter Schmuckal" <peter@schmuckal.com>
Re: [Residence Organs]  Relay  MISS-INFORMATION for "shoppers"
  by "John R. Ball" <fitball@cox.net>
Re: [Residence Organs]  Re: Relays
  by "rnewman" <rnewman@shop.rutgers.edu>
Cleaning zinc pipes
  by "rnewman" <rnewman@shop.rutgers.edu>
 

(back) Subject: Re: PC Based Relay System From: "Larry Chace" <RLC1@etnainstruments.com> Date: Sun, 28 Sep 2003 10:40:00 -0400   An example of a PC-based organ control system is Tim Rickman's "Uniflex". The system is implemented as a program that runs on the PC and uses the PC's resources such as disk, memory, and do on. An interface card is installed in the PC, and it has a ribbon cable connection to a series of cards that are installed external to the PC. Input cards accept normal organ DC signals coming from the contacts on keys, stops, swell shoes, pistons, and so on. They can also accept analog inputs. Output cards drive magnets that might operate a chest action, a stoptab action, or = other similar items. The organ's specification and other details are contained in a configuration file that can be edited as needed and that gets "compiled" (in some general sense of that word) into the data that is used to control the organ in real time.   Other systems that were recently mentioned (Emutek and Artisan, for example), do *not* use a PC for the control system itself but are instead implemented using dedicated microcontrollers. The organ specification = *is* processed by a program running on a PC and the results are then = down-loaded into the microcontrollers. The PC is used only to change the specification, not to control the organ.   (I think these descriptions are pretty much sorta kinda correct... ;-)   Larry Chace      
(back) Subject: Re: Relay Systems From: "Larry Chace" <RLC1@etnainstruments.com> Date: Sun, 28 Sep 2003 10:44:24 -0400   "D Heimer" <dheimer@sensible.net> suggested a "hybrid" approach that would use a solid-state control system to augment an existing electro-mechanical relay system. That approach does work and can be a sensible way to go.   It might prove to be only a very small savings, however, depending upon = the exact specification and the cost of the components. If the existing e-m relay would need to be re-wired to match the new specification, then the savings might well be swallowed up in all the extra work for that re-wiring. It all depends... ;-)   Larry Chace        
(back) Subject: Re: [Residence Organs] Re: PC Based Relay System From: "Bob Loesch" <rrloesch@jps.net> Date: Sun, 28 Sep 2003 09:48:45 -0700   Thanks, Larry. I was pretty hazy on these myself, having only played one, =   which, come to think of it, might have been a 'Uniflex', since Tim inheirited the organ when its owner passed away. Nice relay, at any rate!   At 10:40 AM 9/28/2003 -0400, Larry Chace wrote: >An example of a PC-based organ control system is Tim Rickman's "Uniflex". >The system is implemented as a program that runs on the PC and uses the >PC's resources such as disk, memory, and do on. An interface card is >installed in the PC, and it has a ribbon cable connection to a series of >cards that are installed external to the PC. Input cards accept normal >organ DC signals coming from the contacts on keys, stops, swell shoes, >pistons, and so on. They can also accept analog inputs. Output cards >drive magnets that might operate a chest action, a stoptab action, or = other >similar items. The organ's specification and other details are contained >in a configuration file that can be edited as needed and that gets >"compiled" (in some general sense of that word) into the data that is = used >to control the organ in real time. > >Other systems that were recently mentioned (Emutek and Artisan, for >example), do *not* use a PC for the control system itself but are instead >implemented using dedicated microcontrollers. The organ specification = *is* >processed by a program running on a PC and the results are then = down-loaded >into the microcontrollers. The PC is used only to change the >specification, not to control the organ. > >(I think these descriptions are pretty much sorta kinda correct... ;-) > >Larry Chace   Regards, Bob      
(back) Subject: Re: [Residence Organs] Relay MISS-INFORMATION for "shoppers" From: "Peter Schmuckal" <peter@schmuckal.com> Date: Sun, 28 Sep 2003 12:28:31 -0700     Though I do not wish to start a flame war, I seemed to have = inadvertantly provoked Mr. Rickman to write a meandering rant as a = response to my comments regarding PC based relay systems.   First off, let me be clear that I am expressing my own opinions which no = one should take as Gospel. As to my qualifications, I have 23 years = experience designing commerical embedded systems, and about 27 years = programming PCs. I've been working on pipe organ control systems for = about the last 17 years. However, I realize this by no means makes me = an expert on the topic.   But my understanding is that the purpose of this forum is for everyone = regardless of their "expertise" to be able to express and discuss their = opinions without getting shouted at.   For the record: I have no problems with PC based, diode matrix, = electromechanical, or tap dancing monkeys when it comes to relay = systems. To each their own.   My basic assertion was that PC based systems are inherently less = reliable than a properly designed embedded system based on = microcontrollers/microprocessors.   PC's include technolgies, hard drives the most obvious one, that have a = lower MTBF than semiconductors in general. Ergo they are somewhat less = reliable. How much that is an overall consideration is up to the user. = I generally have to replace a hard drive or power supply on one of my = computers every two or three years. I have never had to replace (or = discard) an embedded microcontroller on any products I own or have = designed except when damaged by misuse or natural disaster.   As Mr. Rickman points out, the one thing that will really kill any = semiconductor based technology will be a good lightning strike - but if = that happens, neither of us are going to repair their system by a quick = trip to the store on Sunday afternoon.   In practice, most people on this list are DIY'er and replacing a HD once = in a while is no big deal. So the other benefits of a PC based system = might outweight the slight reliability issue.   So by all means lets discuss all types of relay systems, but please - no = shouting.   Thanks,   - Peter Schmuckal            
(back) Subject: Re: [Residence Organs] Relay MISS-INFORMATION for "shoppers" From: "John R. Ball" <fitball@cox.net> Date: Sun, 28 Sep 2003 15:57:45 -0400   If hard disks fail more than one would like in a PC system then why not = resort to other devices. I think that a 1.4mb floppy will hold a substantial C-code Dos-based = pipe organ program and will boot to Dos. Floppies are almost free and no hard disk is needed.   JRB    
(back) Subject: Re: [Residence Organs] Re: Relays From: "rnewman" <rnewman@shop.rutgers.edu> Date: Sun, 28 Sep 2003 21:32:49 -0400   I spent a while trying to decide what relay to go with for my new residence organ. I had a Klann so called "crank and slider" relay on the old organ and wouldn't want to deal with that again. Very difficult to reconfigured and lots of contact problems.   During my search I looked at lots of systems and got quotes from some. I also had a chance to see and play the Irvine Auditorium Austin in Philadelphia which has a new Uniflex relay. I was quite impressed and emailed Tim for a quote for my organ over a year ago but have yet to get a response.   Through most of the process I was leaning toward the Syndyne system but last minute changed my mind and ended up choosing Dave Milton's Opus-Two. The price is very reasonable considering all the features and if it ends up working as well as it is supposed to i'll be a very happy camper.   Btw, Tim made some good points in his post. I personally have mixed feelings about a PC based system (especially being a Mac guy) and hope I won't regret getting an embedded microcontroller system. At least with the Opus-Two system the computer cards are fairly inexpensive and I could buy two spare back up boards for the cost of an inexpensive PC. It also requires some amount of configuration/programming that might not be for everyone. I don't personally mind tinkering around with this kind of stuff.   I am currently in the process of wiring everything up and hope to have something playing by the new year. I'll make sure to post to the list and let you know how I make out. Good luck relay shopping.   -Randy    
(back) Subject: Cleaning zinc pipes From: "rnewman" <rnewman@shop.rutgers.edu> Date: Sun, 28 Sep 2003 22:00:18 -0400       A while back I emailed the list asking for some suggestions for cleaning some really nasty looking zinc pipes. I tried a bunch of different things including TSP, muriatic acid (not suggested for zinc), various detergents, scrubbing bubbles, etc. Nothing really worked as well as i was hoping. Anyway, just tonight I found something, mostly by accident, that seems to work quite well. While using some Super Clean degreaser to clean up parts of my blower for painting, i accidentally over sprayed onto some junk zinc tuba resonators i had lying around. Where the cleaner had landed the pipes they were much shinier looking, so as a test I took a pipe outside and completely sprayed it down. After a few minutes I rinsed it down with water and amazingly enough it came out looking really nice. Much better than any of the other things I have tried. With a coat of Zinsser clear shellac from a spray can, the pipes look almost like new.   I did notice that one of the ingredients in the Super Clean is Sodium Hydroxide (lye) which i was told can turn zinc black, but so far in my tests this didn't seem to happen. If anyone has found anything else that seems to work well on zinc i'd be interested in hearing.   -Randy