DIYAPASON-L Digest #289 - Tuesday, March 27, 2001
 
Re: [Residence Organs]  A diode question
  by "Eric Sagmuller" <ess4@psu.edu>
Re: [Residence Organs]  A diode question
  by "John Vanderlee" <jovanderlee@vassar.edu>
Re: [Residence Organs]  A diode question
  by "Jon Calvo" <jcalvo@mail.state.tn.us>
RE: [Residence Organs]  A diode question
  by "Grandstaff, Larry P." <grandslp@smxcorp.com>
RE: [Residence Organs]  A diode question
  by "Eric Sagmuller" <ess4@psu.edu>
Re: [Residence Organs]  A diode question
  by "Mac Hayes" <mach37@ptw.com>
Diode location
  by <JFick@aol.com>
Re: [Residence Organs]  A diode question
  by "John Vanderlee" <jovanderlee@vassar.edu>
Re: [Residence Organs]  A diode question
  by "Mac Hayes" <mach37@ptw.com>
Organ Installation was Diodes
  by "Eric Sagmuller" <ess4@psu.edu>
Re: [Residence Organs]  Organ Installation was Diodes
  by "Jon Calvo" <jcalvo@mail.state.tn.us>
 

(back) Subject: Re: [Residence Organs] A diode question From: "Eric Sagmuller" <ess4@psu.edu> Date: Tue, 27 Mar 2001 08:06:33 -0500   At 8:01 PM -0800 3/26/01, Peter Schmuckal wrote: >At the risk of picking diode nits: > >Why are 1N4007 diodes recommended over, say 1N4001 diodes? Both are 1A >devices, but the former is rated at 1000V PIV, and the latter is 50V PIV. >   I just knew this question was coming. Yes it's true the 1000V PIV diodes are overkill as far as voltage rating goes. And the others would probably work fine too. I basically mentioned them because the cost difference is so little over the lower voltage versions, and at least, I feel, it's worth spending the small difference on a more "rugged" diode. One could also go to a 3 amp diode, but these I believe are quite a bit more expensive and really not necessary.   As an example, I've used for instance 1N4004 diodes that were well rated for a situation, only to have them short out after a time. I then switched to 1N4007 diodes and had no more problems.   Just my two cents worth. Eric    
(back) Subject: Re: [Residence Organs] A diode question From: "John Vanderlee" <jovanderlee@vassar.edu> Date: Tue, 27 Mar 2001 09:00:07 -0500   >At the risk of picking diode nits: > >Why are 1N4007 diodes recommended over, say 1N4001 diodes? Both are 1A >devices, but the former is rated at 1000V PIV, and the latter is 50V PIV. > >Most organ relays use 10-15V, so I don't see why 50V isn't more than >sufficient. The diode doesn't see the large reverse inductive spike = since >that is in the forward direction for the diode and will cause it to = conduct >(which is the whole reason we're using them). > >I realize that for all pratical purposes there is little cost difference >between the two flavors to justify even this discussion, but I am just >curious if anyone has had any problems with blowing out these diodes?       There is a very good reason!!   The thing these diodes snub out is the inductive kickback voltage which it what causes contact arcing or destruction of solid state drivers.   And the reason is...   When a coil is energized (action magnet/stop action magnet) it sets up a magnetic field around itself. De-energizing the coil causes this field to collapse creating an "inductive kickback", that is the lines of magnetic force "cut" through the windings and actually(briefly) generate a high voltage of the opposite polarity in the coil. This voltage, although = brief, can be extremely high, ten to a hundred times the supply voltage -hence = the arc. The diode connected opposite in polarity to the coil provides a short circuit path for this pulse effectively absorbing the energy before it feeds back on the wires causing contacts to burn and semiconductor junctions to be penetrated.   Thus the higher the voltage rating on the diode, the better the = protection.   That was today's physics lesson :-)   Incidentally, we do have some thousand of those diodes to part with. Any quantity buyers?   John Vanderlee Sr. Elect Tech Vassar College Dept. of Physics & Astronomy      
(back) Subject: Re: [Residence Organs] A diode question From: "Jon Calvo" <jcalvo@mail.state.tn.us> Date: Tue, 27 Mar 2001 08:23:23 -0600   --=3D_451EB275.E988276F Content-Type: text/plain; charset=3DUS-ASCII Content-Transfer-Encoding: quoted-printable   ** For Your Eyes Only ** ** High Priority **   John V=3D20 Question do you have the set of 18 chime tubes available that you told me = =3D about several months ago=3D20 John C   >>> jovanderlee@vassar.edu 03/27/01 08:00AM >>>=3D20 >At the risk of picking diode nits:=3D20 >=3D20 >Why are 1N4007 diodes recommended over, say 1N4001 diodes? Both are = 1A=3D20 >devices, but the former is rated at 1000V PIV, and the latter is 50V =3D PIV.=3D20 >=3D20 >Most organ relays use 10-15V, so I don't see why 50V isn't more than=3D20 >sufficient. The diode doesn't see the large reverse inductive spike =3D since=3D20 >that is in the forward direction for the diode and will cause it to =3D conduct=3D20 >(which is the whole reason we're using them).=3D20 >=3D20 >I realize that for all pratical purposes there is little cost = difference=3D =3D20 >between the two flavors to justify even this discussion, but I am = just=3D20 >curious if anyone has had any problems with blowing out these = diodes?=3D20       There is a very good reason!!=3D20   The thing these diodes snub out is the inductive kickback voltage which = =3D it=3D20 what causes contact arcing or destruction of solid state drivers.=3D20   And the reason is...=3D20   When a coil is energized (action magnet/stop action magnet) it sets up =3D a=3D20 magnetic field around itself. De-energizing the coil causes this field =3D to=3D20 collapse creating an "inductive kickback", that is the lines of = magnetic=3D20=3D   force "cut" through the windings and actually(briefly) generate a = high=3D20 voltage of the opposite polarity in the coil. This voltage, although =3D brief,=3D20 can be extremely high, ten to a hundred times the supply voltage -hence = =3D the=3D20 arc. The diode connected opposite in polarity to the coil provides a =3D short=3D20 circuit path for this pulse effectively absorbing the energy before = it=3D20 feeds back on the wires causing contacts to burn and semiconductor=3D20 junctions to be penetrated.=3D20   Thus the higher the voltage rating on the diode, the better the = protection.=3D =3D20   That was today's physics lesson :-)=3D20   Incidentally, we do have some thousand of those diodes to part with. =3D Any=3D20 quantity buyers?=3D20   John Vanderlee=3D20 Sr. Elect Tech=3D20 Vassar College Dept. of Physics & Astronomy=3D20       DIYAPASON-L: a Discussion list for owners and builders of their own=3D20 Residence Pipe Organs.=3D20 HOMEPAGE : http://www.diyapason.pipechat.org=3D20 List: mailto:DIYAPASON-L@pipechat.org=3D20 Administration: mailto:owner-DIYAPASON@pipechat.org=3D20   --=3D_451EB275.E988276F Content-Type: text/html; charset=3DISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Description: HTML   <!DOCTYPE HTML PUBLIC "-//W3C//DTD W3 HTML//EN"> <HTML> <HEAD>   <META content=3D3D"text/html; charset=3D3Diso-8859-1" = http-equiv=3D3DContent-Type=3D > <META content=3D3D'"MSHTML 4.72.3612.1706"' name=3D3DGENERATOR> </HEAD> <BODY style=3D3D"FONT: 8pt MS Sans Serif; MARGIN-LEFT: 2px; MARGIN-TOP: = =3D 2px"> <DIV><FONT size=3D3D1>John V </FONT></DIV> <DIV><FONT size=3D3D1>Question do you have the set of 18 chime tubes =3D available that=3D20 you told me about several months ago </FONT></DIV> <DIV><FONT size=3D3D1>John C</FONT><BR><BR>&gt;&gt;&gt; <A=3D20 href=3D3D"mailto:jovanderlee@vassar.edu">jovanderlee@vassar.edu</A> = 03/27/01 =3D 08:00AM=3D20 &gt;&gt;&gt; <BR>&gt;At the risk of picking diode nits: <BR>&gt; = <BR>&gt;Wh=3D y are=3D20 1N4007 diodes recommended over, say 1N4001 diodes? Both are 1A = <BR>&gt;devi=3D ces,=3D20 but the former is rated at 1000V PIV, and the latter is 50V PIV. =3D <BR>&gt;=3D20 <BR>&gt;Most organ relays use 10-15V, so I don't see why 50V isn't more = =3D than=3D20 <BR>&gt;sufficient. The diode doesn't see the large reverse inductive =3D spike=3D20 since <BR>&gt;that is in the forward direction for the diode and will =3D cause it=3D20 to conduct <BR>&gt;(which is the whole reason we're using them). =3D <BR>&gt;=3D20 <BR>&gt;I realize that for all pratical purposes there is little cost =3D difference=3D20 <BR>&gt;between the two flavors to justify even this discussion, but I am =3D just=3D20 <BR>&gt;curious if anyone has had any problems with blowing out these =3D diodes?=3D20 <BR><BR><BR><BR>There is a very good reason!! <BR><BR>The thing these =3D diodes=3D20 snub out is the inductive kickback voltage which it <BR>what causes =3D contact=3D20 arcing or destruction of solid state drivers. <BR><BR>And the reason =3D is...=3D20 <BR><BR>When a coil is energized (action magnet/stop action magnet) it =3D sets up a=3D20 <BR>magnetic field around itself. De-energizing the coil causes this field = =3D to=3D20 <BR>collapse creating an &quot;inductive kickback&quot;, that is the lines = =3D of=3D20 magnetic <BR>force &quot;cut&quot; through the windings and = actually(briefl=3D y)=3D20 generate a high <BR>voltage of the opposite polarity in the coil. This =3D voltage,=3D20 although brief, <BR>can be extremely high, ten to a hundred times the =3D supply=3D20 voltage -hence the <BR>arc. The diode connected opposite in polarity to = =3D the coil=3D20 provides a short <BR>circuit path for this pulse effectively absorbing =3D the=3D20 energy before it <BR>feeds back on the wires causing contacts to burn =3D and=3D20 semiconductor <BR>junctions to be penetrated. <BR><BR>Thus the higher =3D the=3D20 voltage rating on the diode, the better the protection. <BR><BR>That was = =3D today's=3D20 physics lesson :-) <BR><BR>Incidentally, we do have some thousand of =3D those=3D20 diodes to part with. Any <BR>quantity buyers? <BR><BR>John Vanderlee =3D <BR>Sr.=3D20 Elect Tech <BR>Vassar College Dept. of Physics &amp; Astronomy=3D20 <BR><BR><BR><BR>DIYAPASON-L: a Discussion list for owners and builders of = =3D their=3D20 own <BR>Residence Pipe Organs. <BR>HOMEPAGE : <U><A=3D20 href=3D3D"http://www.diyapason.pipechat.org/">http://www.diyapason.pipechat= .o=3D rg</A></U>=3D20 <BR>List: <U><A=3D20 href=3D3D"mailto:DIYAPASON-L@pipechat.org">mailto:DIYAPASON-L@pipechat.org<= /A=3D ></U>=3D20 <BR>Administration: <U><A=3D20 href=3D3D"mailto:owner-DIYAPASON@pipechat.org">mailto:owner-DIYAPASON@pipec= ha=3D t.org</A></U>=3D20 <BR><BR></DIV></BODY></HTML>   --=3D_451EB275.E988276F--  
(back) Subject: RE: [Residence Organs] A diode question From: "Grandstaff, Larry P." <grandslp@smxcorp.com> Date: Tue, 27 Mar 2001 10:02:26 -0500   The one thing that you want to consider concerning the mounting of the diodes is that farther from the coil you are, the more EMI signal you are going to generate and the less effective the diode is.   The wires from the point where the diode is mounted to the coil become an antenna and will cause interference on older electronic products that do not have good EMI rejection circuits.   The discharge is going to follow the path of least resistance, so as the length of wire increases the effect of the diode is reduced.   Use an old AM transistor radio to test how well your diode is working to suppress the back EMF. You will never get rid of all the interference, = but you will certainly reduce it to tolerable level by mounting the diode = right to the coil.   Larry Grandstaff    
(back) Subject: RE: [Residence Organs] A diode question From: "Eric Sagmuller" <ess4@psu.edu> Date: Tue, 27 Mar 2001 10:10:08 -0500   At 10:02 AM -0500 3/27/01, Grandstaff, Larry P. wrote: >The one thing that you want to consider concerning the mounting of the >diodes is that farther from the coil you are, the more EMI signal you are >going to generate and the less effective the diode is..... >   Thanks for the helpful information Larry. Wire "inductance" certainly comes into play here.   Eric    
(back) Subject: Re: [Residence Organs] A diode question From: "Mac Hayes" <mach37@ptw.com> Date: Tue, 27 Mar 2001 08:27:44 -0800   Can somebody direct me to the publication that has a schematic diagram (or maybe it was a pictorial diagram) of how the diodes should be wired? I'm sure I once saw a diagram of some sort, but can't remember where. I have some back issures of the ISO journal, Diapason, The Tracker (surely no diodes in THERE!), and a few AGO magazines. Surely not in Barnes, or the books by E. M. Skinner, either.   Mac Hayes  
(back) Subject: Diode location From: <JFick@aol.com> Date: Tue, 27 Mar 2001 11:44:19 EST   Regarding the location of diodes, it's usually best to put any type of = noise/spark suppression device as close to the noise source as possible. = In the case of a pipe organ, that would be at each magnet in the chests = and at each coil in the console.   Previous notes have correctly explained that several hundred volts can be = generated across an unsuppressed organ magnet coil. If this voltage is = shorted out by a diode located some distance away from the coil, then the = short-circuit current generated by this voltage runs that distance. It's = current in a wire that generates a corresponding magnetic field along the = wire. If other wires run parallel to that wire, they pick up the magentic = field and convert it to current, which may or may be significant, = depending on the application. Current only flows if there is a complete = circuit, out and back. The "out" current is in one direction; the "back" = current is in the reverse direction. If the "out" wire for the = short-circuited current is tightly mechanically coupled to the "back" = wire, then the two magnetic fields are in opposite directions and = effectively cancel each other out. But that's not usually the case in = pipe organs where there is a single loose ground return wire.   Where might this be important? In my own scenario, I have console cabling = that parallels PA system cabling for something like 90 feet. If I were to = install diodes in the console expecting to kill the magnet spikes from the = chests, then I can fully expect that I will have all sorts of magnetic = fields spraying over that 90 feet and coupling into my PA system cabling. = (Technical folks will be interested to know that the PA system cabling is = a 22-twisted pair snake and the mixer has differential inputs, but I'd say = that 40-50 simultaneous pipe magnets whose reverse EMF currents are = suppressed at the console could, intuitively, overcome the best = common-mode rejection at the mixer inputs.) Thus, I installed diodes at = the 500+ magnets. I don't expect any PA system problems when we fire it = up.   In a week or two I'll find out for sure! You might be interested to check = out our progress at http://www.ChristMemorialChurch.org/organ.html   Jon Fick Westford, Vermont  
(back) Subject: Re: [Residence Organs] A diode question From: "John Vanderlee" <jovanderlee@vassar.edu> Date: Tue, 27 Mar 2001 11:50:26 -0500   >Can somebody direct me to the publication that has a schematic diagram >(or maybe it was a pictorial diagram) of how the diodes should be >wired? I'm sure I once saw a diagram of some sort, but can't remember >where. I have some back issures of the ISO journal, Diapason, The >Tracker (surely no diodes in THERE!), and a few AGO magazines. Surely >not in Barnes, or the books by E. M. Skinner, either. > >Mac Hayes > >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       Mac,   The coil of your electric action is the source of the electrical spikes. The coil has two connections(wires) on it. If you don't know the polarity of the voltage powering it; Get a voltmeter. Set it to read DC voltage. = Set the range to read about 20 volts. The leads from the meter should be red and black. Red should be plugged into the meter where it says "+" or "positive" and the black similarly into "-" or "common". Energize the action and touch the lead tips to the two connections. A digital meter = will show the voltage number preceded by a "+" or preceded by nothing. If it reads a voltage preceded by "-" or "neg", then reverse the leads. When you read "pos" or "+" the red wire is connected to the positive side of your coil(circuit) and obviously the black to the negative. If you use an "analog" meter with a pointer the needle should deflect to the right to indicate proper polarity.   Now that you have determined the polarity of your coil circuit you can connect a diode accross it. The diode will have a stripe around its body = on one end. This stripe indicates the cathode or negative side of the diode. Since the diode is hooked accross backwards to snub the spikes, the stripe goes on the positive side of your coil and naturally the other end to the negative side.   Now that you have determined which way your circuits work you can install them all the same. Don't use too much heat with your solder iron!   Hope this helps!   John V        
(back) Subject: Re: [Residence Organs] A diode question From: "Mac Hayes" <mach37@ptw.com> Date: Tue, 27 Mar 2001 09:18:10 -0800   John Vanderlee wrote: > Mac, > ... > Now that you have determined the polarity of your coil circuit you > can connect a diode accross it. ...   > Hope this helps!     Thanks, John. That is all I needed to know. Now all I need to do is count my magnets & coils and see how many I can 'take off your hands' - if you have any left, that is, by the time I've finished counting.   Mac  
(back) Subject: Organ Installation was Diodes From: "Eric Sagmuller" <ess4@psu.edu> Date: Tue, 27 Mar 2001 12:54:48 -0500   At 11:44 AM -0500 3/27/01, JFick@aol.com wrote: > > >In a week or two I'll find out for sure! You might be interested to >check out our progress at >http://www.ChristMemorialChurch.org/organ.html >   Great pictures and job Jon! Now if there was only a surefire way to talk churches into removing all that sound absorbing carpet and padding! I attend an absolutely gorgeous Episcopalian design church with a very high wood truss arched ceiling, and lots of woodwork. But the acoustics are absolutely dead in this building due to carpet everywhere and padded pews. What to do, but I guess it's a syndrome of this day and age!   You all have a great day, Eric    
(back) Subject: Re: [Residence Organs] Organ Installation was Diodes From: "Jon Calvo" <jcalvo@mail.state.tn.us> Date: Tue, 27 Mar 2001 12:11:03 -0600   --=3D_6F34981B.EB8A2537 Content-Type: text/plain; charset=3DUS-ASCII Content-Transfer-Encoding: quoted-printable   ** For Your Eyes Only ** ** High Priority **   Jon Great photos what brand of console is that it look like a Schantz=3D20 Reg. carpet in churches there is a local Catholic church here in Nashville = =3D has the best Acoustics marble floor etc . 1957 Kilgen organ 27 ranks =3D sounds like 127 has a 6 Sec. delay a grand example of non carpeted =3D churches=3D20   >>> ess4@psu.edu 03/27/01 11:54AM >>> At 11:44 AM -0500 3/27/01, JFick@aol.com wrote: > > >In a week or two I'll find out for sure! You might be interested to=3D20 >check out our progress at=3D20 >http://www.ChristMemorialChurch.org/organ.html >   Great pictures and job Jon! Now if there was only a surefire way to=3D20 talk churches into removing all that sound absorbing carpet and=3D20 padding! I attend an absolutely gorgeous Episcopalian design church=3D20 with a very high wood truss arched ceiling, and lots of woodwork.=3D20 But the acoustics are absolutely dead in this building due to carpet=3D20 everywhere and padded pews. What to do, but I guess it's a syndrome=3D20 of this day and age!   You all have a great day, Eric     DIYAPASON-L: a Discussion list for owners and builders of their own=3D20 Residence Pipe Organs. HOMEPAGE : http://www.diyapason.pipechat.org List: mailto:DIYAPASON-L@pipechat.org Administration: mailto:owner-DIYAPASON@pipechat.org   --=3D_6F34981B.EB8A2537 Content-Type: text/html; charset=3DISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Description: HTML   <!DOCTYPE HTML PUBLIC "-//W3C//DTD W3 HTML//EN"> <HTML> <HEAD>   <META content=3D3D"text/html; charset=3D3Diso-8859-1" = http-equiv=3D3DContent-Type=3D > <META content=3D3D'"MSHTML 4.72.3612.1706"' name=3D3DGENERATOR> </HEAD> <BODY style=3D3D"FONT: 8pt MS Sans Serif; MARGIN-LEFT: 2px; MARGIN-TOP: = =3D 2px"> <DIV><FONT size=3D3D1>Jon Great photos what brand of console is that it = look =3D like a=3D20 Schantz </FONT></DIV> <DIV><FONT size=3D3D1>Reg. carpet in churches there is a local Catholic = =3D church here=3D20 in Nashville has the best Acoustics marble floor etc . 1957 Kilgen organ = =3D 27=3D20 ranks sounds like 127 has a 6 Sec. delay a grand example of non = carpeted=3D20=3D   churches </FONT><BR><BR>&gt;&gt;&gt; ess4@psu.edu 03/27/01 11:54AM=3D20 &gt;&gt;&gt;<BR>At 11:44 AM -0500 3/27/01, JFick@aol.com=3D20 wrote:<BR>&gt;<BR>&gt;<BR>&gt;In a week or two I'll find out for = sure!&nbsp=3D ; You=3D20 might be interested to <BR>&gt;check out our progress at <BR>&gt;<A=3D20 href=3D3D"http://www.christmemorialchurch.org/organ.html">http://www.Christ= Me=3D morialChurch.org/organ.html</A><BR>&gt;<BR><BR>Great=3D20 pictures and job Jon!&nbsp; Now if there was only a surefire way to =3D <BR>talk=3D20 churches into removing all that sound absorbing carpet and <BR>padding! I = =3D attend=3D20 an absolutely gorgeous Episcopalian design church <BR>with a very high =3D wood=3D20 truss arched ceiling, and lots of woodwork. <BR>But the acoustics are =3D absolutely=3D20 dead in this building due to carpet <BR>everywhere and padded pews. What = =3D to do,=3D20 but I guess it's a syndrome <BR>of this day and age!<BR><BR>You all have a = =3D great=3D20 day,<BR>Eric<BR><BR><BR>DIYAPASON-L: a Discussion list for owners and =3D builders=3D20 of their own <BR>Residence Pipe Organs.<BR>HOMEPAGE : <A=3D20 href=3D3D"http://www.diyapason.pipechat.org/">http://www.diyapason.pipechat= .o=3D rg</A><BR>List:=3D20 <A=3D20 href=3D3D"mailto:DIYAPASON-L@pipechat.org">mailto:DIYAPASON-L@pipechat.org<= /A=3D ><BR>Administration:&nbsp;=3D20 <A=3D20 href=3D3D"mailto:owner-DIYAPASON@pipechat.org">mailto:owner-DIYAPASON@pipec= ha=3D t.org</A><BR><BR></DIV></BODY></HTML>   --=3D_6F34981B.EB8A2537--