DIYAPASON-L Digest #607 - Saturday, July 27, 2002
 
Organ phenomena
  by "Drew Taylor" <drewt@loritsu.com>
Re: [Residence Organs]  Organ phenomena
  by "Steven" <sdurham11@attbi.com>
RE: [Residence Organs]  Organ phenomena
  by "ATOS" <atos@stirlingprop.com>
Organ phenomena
  by "Richard Schneider" <arpschneider@starband.net>
Fw: [Residence Organs]  Organ phenomena
  by "D Heimer" <dheimer@sensible.net>
Re: [Residence Organs]  Organ phenomena
  by "D Heimer" <dheimer@sensible.net>
Re: [Residence Organs]  Organ phenomena
  by "Jon" <sparky@CEINetworks.com>
 

(back) Subject: Organ phenomena From: "Drew Taylor" <drewt@loritsu.com> Date: Sat, 27 Jul 2002 14:55:32 -0400   I have run into a very intriguing problem recently, maybe someone can = offer some insight. Take caution though, it's long (winded).   On the small organ I am building, I have one rank of pipes wired directly = into the keyboard. That works fine for one rank, but now I am adding a second in = the same division. I plan to use gang switches to wire it in, so the following = problem isn't really a problem, just puzzling.   While I was still wiring the second manual and had extra time, I figured I = would wire the second rank (4' Flute) into the first rank (4' Principal) on a terminal = board. Meaning that I connected the 61 positive leads from the 4' Flute into the 61 = positive leads coming from the 4' Principal, which then went on to the keyboard. The = negative buss leads from both ranks were then connected to the negative lead on the = power supply.   This worked just fine, both ranks played as expected. But, when I tried = to switch the stops (removed the negative lead from the 4' Principal from the power = supply), that's when a strange phenomenon was observed.   I pulled the negative buss lead coming from the 4' Principal rank off, = disconnecting it from the power supply, which (I thought) should have only let the 4' Flute = play and not the Principal. To my surprise, the 4' Principal still played! It's = baffling, the negative buss lead going to the Principal valves was disconnected, yet = they still played. I checked out the resistance on each of the 61 valves on both ranks = (between the positive lead and the negative buss) and every valve checked out, no = crossing over. When I put a volt meter between the negative and positive terminal on a = valve in the Principal, it read 5vdc (the power supply is supplying 12vdc to the = organ). Of course when the negative buss for the Principal was reconnected to the negative = power supply lead, it went back up to 12vdc and everything was fine. Could it be that one of the valves in the 4' Flute (which was still = connected) is crossing over, spilling into the Principal and therefore powering the negative buss = in that rank? That seems unlikely to me but who knows. But like I said before, this = isn't a real problem since I will be isolating each rank with a gang switch. Just a = curiosity.   This could just be some mundane basic electrical happening that's being = masked by the hundreds of pairs of wires and complexity of wiring. Has anyone else = encountered this?   -Drew Taylor        
(back) Subject: Re: [Residence Organs] Organ phenomena From: "Steven" <sdurham11@attbi.com> Date: Sat, 27 Jul 2002 13:54:33 -0700   Drew:   I too had the same problem before I separated, with gang switches, the = three ranks on my practice organ. I never was never able to completely figure = out what was going on. Sometimes every note would play at once which can be quite disturbing. I'm just lucky I didn't fry my new Reisner/OSI Electric Pallet Valves!   Steven Durham Portland, OR     ----- Original Message ----- From: "Drew Taylor" <drewt@loritsu.com> To: <DIYAPASON-L@pipechat.org> Sent: Saturday, July 27, 2002 11:55 AM Subject: [Residence Organs] Organ phenomena     > I have run into a very intriguing problem recently, maybe someone can offer some > insight. Take caution though, it's long (winded). > > On the small organ I am building, I have one rank of pipes wired = directly into the > keyboard. That works fine for one rank, but now I am adding a second in the same > division. I plan to use gang switches to wire it in, so the following problem isn't really > a problem, just puzzling. > > While I was still wiring the second manual and had extra time, I figured = I would wire the > second rank (4' Flute) into the first rank (4' Principal) on a terminal board. Meaning > that I connected the 61 positive leads from the 4' Flute into the 61 positive leads > coming from the 4' Principal, which then went on to the keyboard. The negative buss > leads from both ranks were then connected to the negative lead on the power supply. > > This worked just fine, both ranks played as expected. But, when I tried to switch the > stops (removed the negative lead from the 4' Principal from the power supply), that's > when a strange phenomenon was observed. > > I pulled the negative buss lead coming from the 4' Principal rank off, disconnecting it > from the power supply, which (I thought) should have only let the 4' = Flute play and > not the Principal. To my surprise, the 4' Principal still played! It's baffling, the > negative buss lead going to the Principal valves was disconnected, yet they still played. > I checked out the resistance on each of the 61 valves on both ranks (between the > positive lead and the negative buss) and every valve checked out, no crossing over. > When I put a volt meter between the negative and positive terminal on a valve in the > Principal, it read 5vdc (the power supply is supplying 12vdc to the organ). Of course > when the negative buss for the Principal was reconnected to the negative power supply > lead, it went back up to 12vdc and everything was fine. > Could it be that one of the valves in the 4' Flute (which was still connected) is crossing > over, spilling into the Principal and therefore powering the negative = buss in that rank? > That seems unlikely to me but who knows. But like I said before, this isn't a real > problem since I will be isolating each rank with a gang switch. Just a curiosity. > > This could just be some mundane basic electrical happening that's being masked by the > hundreds of pairs of wires and complexity of wiring. Has anyone else encountered > this? > > -Drew Taylor > > > > > DIYAPASON-L: a Discussion list for owners and builders of their own > Residence Pipe Organs. > HOMEPAGE : http://www.diyapason.pipechat.org > List: mailto:DIYAPASON-L@pipechat.org > Administration: mailto:owner-DIYAPASON@pipechat.org > >    
(back) Subject: RE: [Residence Organs] Organ phenomena From: "ATOS" <atos@stirlingprop.com> Date: Sat, 27 Jul 2002 18:51:40 -0500   If you care to take a look at the drawing located at http://atos.stirlingprop.com/organrun.gif, you will see your problem. As I was attempting to answer your question, I sketched the current flow out so = I could explain it better. I realized making the diagram with the indicated current flows available to anyone who is interested makes it easier to understand, so I posted it on a web server where everyone can see it. The problem occurs when current on the disconnected rank attempts to seek = ground by following the path of least resistance which, in this case is first an ajacent magnet on the same rank and then through a corresponding (non-playing) magnet on the other rank. From there, it's a simple case of = a home run back to the power supply. Hopes this helps.   -----Original Message----- From: DIYAPASON-L@pipechat.org [mailto:DIYAPASON-L@pipechat.org]On Behalf Of Drew Taylor Sent: Saturday, July 27, 2002 1:56 PM To: DIYAPASON-L@pipechat.org Subject: [Residence Organs] Organ phenomena     I have run into a very intriguing problem recently, maybe someone can = offer some insight. Take caution though, it's long (winded).   On the small organ I am building, I have one rank of pipes wired directly into the keyboard. That works fine for one rank, but now I am adding a second in = the same division. I plan to use gang switches to wire it in, so the following problem isn't really a problem, just puzzling.   While I was still wiring the second manual and had extra time, I figured I would wire the second rank (4' Flute) into the first rank (4' Principal) on a terminal board. Meaning that I connected the 61 positive leads from the 4' Flute into the 61 positive leads coming from the 4' Principal, which then went on to the keyboard. The negative buss leads from both ranks were then connected to the negative lead on the = power supply.   This worked just fine, both ranks played as expected. But, when I tried = to switch the stops (removed the negative lead from the 4' Principal from the power supply), that's when a strange phenomenon was observed.   I pulled the negative buss lead coming from the 4' Principal rank off, disconnecting it from the power supply, which (I thought) should have only let the 4' Flute play and not the Principal. To my surprise, the 4' Principal still played! It's baffling, the negative buss lead going to the Principal valves was disconnected, yet = they still played. I checked out the resistance on each of the 61 valves on both ranks = (between the positive lead and the negative buss) and every valve checked out, no crossing over. When I put a volt meter between the negative and positive terminal on a valve in the Principal, it read 5vdc (the power supply is supplying 12vdc to the = organ). Of course when the negative buss for the Principal was reconnected to the negative power supply lead, it went back up to 12vdc and everything was fine. Could it be that one of the valves in the 4' Flute (which was still connected) is crossing over, spilling into the Principal and therefore powering the negative buss in that rank? That seems unlikely to me but who knows. But like I said before, this = isn't a real problem since I will be isolating each rank with a gang switch. Just a curiosity.   This could just be some mundane basic electrical happening that's being masked by the hundreds of pairs of wires and complexity of wiring. Has anyone else encountered this?   -Drew Taylor         DIYAPASON-L: a Discussion list for owners and builders of their own Residence Pipe Organs. HOMEPAGE : http://www.diyapason.pipechat.org List: mailto:DIYAPASON-L@pipechat.org Administration: mailto:owner-DIYAPASON@pipechat.org      
(back) Subject: Organ phenomena From: "Richard Schneider" <arpschneider@starband.net> Date: Sat, 27 Jul 2002 19:06:16 -0500     Steven wrote: > Drew: > I too had the same problem before I separated, with gang switches, the = three > ranks on my practice organ. I never was never able to completely figure = out > what was going on. Sometimes every note would play at once which can be > quite disturbing. I'm just lucky I didn't fry my new Reisner/OSI = Electric > Pallet Valves!   OK, What's going on is quite simple. There is supposedly no "return path" between the magnets whose return buss has been disconnected from the power supply, but actually there is, in the form of the other neighboring coils providing a path for current to flow. That's why you're seeing 5 volts, since the coils are now connected in series, rather than parallel (prolly more likely 6 volts, which is half of the supply voltage.   If you used Isolation Diodes, which permit the current to flow only one direction, that would not be a problem. However, if you have two or three magnets connected to the same contact in the manner you describe, you will have overloaded contacts which will quickly burn out.   This is why gang switches and isolation diodes are required.   I hope this somewhat simplistic explanation helps.   Faithfully,   -- Richard Schneider, PRES/CEO SCHNEIDER PIPE ORGANS, Inc. Pipe Organ Builders 41-43 Johnston St./P.O. Box 137 Kenney, IL 61749-0137 (217) 944-2454 VOX (217) 944-2527 FAX mailto:arp@schneiderpipeorgans.com SHOP EMAIL mailto:arp@starband.net SHOP SATELLITE EMAIL mailto:arpschneider@starband.net HOME OFFICE EMAIL http://www.schneiderpipeorgans.com WEB PAGE URL    
(back) Subject: Fw: [Residence Organs] Organ phenomena From: "D Heimer" <dheimer@sensible.net> Date: Sat, 27 Jul 2002 20:08:49 -0400     ----- Original Message ----- From: "D Heimer" <dheimer@sensible.net> To: "Residence Organ List" <DIYAPASON-L@pipechat.org> Sent: Saturday, July 27, 2002 7:58 PM Subject: Re: [Residence Organs] Organ phenomena     > Drew, I had the same problem on the first organ I built (the one your > stoptabs came from). I beleive the problem was backfeed through the coils. > Some of the notes would often hang fire too. I interposed diodes between > the - side of the magnets and the groundbus. I think they were ~ 1A = 100V. > That was 1972, in retrospect I believe a little beefier diode would be > better. Perhaps an EE or someone with more recent experience in this matter > on the list could come up with a better choice of diodes. > Dave > Heimer > > ----- Original Message ----- > From: "Drew Taylor" <drewt@loritsu.com> > To: <DIYAPASON-L@pipechat.org> > Sent: Saturday, July 27, 2002 2:55 PM > Subject: [Residence Organs] Organ phenomena > > > > > > > On the small organ I am building, I have one rank of pipes wired directly > into the > > keyboard. > > > > I pulled the negative buss lead coming from the 4' Principal rank off, > disconnecting it > > from the power supply, which (I thought) should have only let the 4' Flute > play and > > not the Principal. To my surprise, the 4' Principal still played! > > > -Drew Taylor > > > > > > > > > > DIYAPASON-L: a Discussion list for owners and builders of their own > > Residence Pipe Organs. > > HOMEPAGE : http://www.diyapason.pipechat.org > > List: mailto:DIYAPASON-L@pipechat.org > > Administration: mailto:owner-DIYAPASON@pipechat.org > > > > >    
(back) Subject: Re: [Residence Organs] Organ phenomena From: "D Heimer" <dheimer@sensible.net> Date: Sat, 27 Jul 2002 19:58:58 -0400   Drew, I had the same problem on the first organ I built (the one your stoptabs came from). I beleive the problem was backfeed through the = coils. Some of the notes would often hang fire too. I interposed diodes = between the - side of the magnets and the groundbus. I think they were ~ 1A 100V. That was 1972, in retrospect I believe a little beefier diode would be better. Perhaps an EE or someone with more recent experience in this = matter on the list could come up with a better choice of diodes. = Dave Heimer   ----- Original Message ----- From: "Drew Taylor" <drewt@loritsu.com> To: <DIYAPASON-L@pipechat.org> Sent: Saturday, July 27, 2002 2:55 PM Subject: [Residence Organs] Organ phenomena       > > On the small organ I am building, I have one rank of pipes wired = directly into the > keyboard. > > I pulled the negative buss lead coming from the 4' Principal rank off, disconnecting it > from the power supply, which (I thought) should have only let the 4' = Flute play and > not the Principal. To my surprise, the 4' Principal still played!   > -Drew Taylor > > > > > DIYAPASON-L: a Discussion list for owners and builders of their own > Residence Pipe Organs. > HOMEPAGE : http://www.diyapason.pipechat.org > List: mailto:DIYAPASON-L@pipechat.org > Administration: mailto:owner-DIYAPASON@pipechat.org > >    
(back) Subject: Re: [Residence Organs] Organ phenomena From: "Jon" <sparky@CEINetworks.com> Date: Sat, 27 Jul 2002 20:19:26 -0400   Instead of disconnecting the rank you do not want to play, try switching from the negative on the power supply to the positive. You will then have zero potential and no chance of playing. Just a thought - anybody see a problem with it?   ~jon