DIYAPASON-L Digest #690 - Thursday, November 21, 2002
 
Re: DIYAPASON-L Digest #689 - 11/20/02
  by <Jess4203@aol.com>
Re: [Residence Organs]  Load down discussion
  by "John Vanderlee" <jovanderlee@vassar.edu>
Re: [Residence Organs]  Re: DIYAPASON-L Digest #687 - 11/18/02
  by "John Vanderlee" <jovanderlee@vassar.edu>
Re: [Residence Organs]  Load down discussion
  by "Eric Sagmuller" <ess4@psu.edu>
 

(back) Subject: Re: DIYAPASON-L Digest #689 - 11/20/02 From: <Jess4203@aol.com> Date: Thu, 21 Nov 2002 01:42:51 EST     --part1_189.113b6838.2b0dda6b_boundary Content-Type: text/plain; charset=3D"US-ASCII" Content-Transfer-Encoding: 7bit   In a message dated 11/21/02 12:30:58 AM Eastern Standard Time, Father Arp writes: > It is > > far less bugggy than Visual Cadd. > Thanks, Father Arp,   For the very current info and for the beautiffful [computer-type] figggure of spppeech <BG>. I'd like to hear what something like this = would cost when ready.   Best Regards & Respectfully, Roy Kersey     --part1_189.113b6838.2b0dda6b_boundary Content-Type: text/html; charset=3D"US-ASCII" Content-Transfer-Encoding: 7bit   <HTML><FONT FACE=3Darial,helvetica><FONT SIZE=3D2>In a message dated = 11/21/02 12:30:58 AM Eastern Standard Time, Father Arp writes: <BR><BLOCKQUOTE TYPE=3DCITE style=3D"BORDER-LEFT: #0000ff 2px solid; = MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">It is <BR>&gt; far less bugggy than Visual Cadd. <BR></FONT><FONT COLOR=3D"#000000" SIZE=3D3 FAMILY=3D"SANSSERIF" = FACE=3D"arial" LANG=3D"0"></BLOCKQUOTE> <BR></FONT><FONT COLOR=3D"#000000" SIZE=3D2 FAMILY=3D"SANSSERIF" = FACE=3D"Arial" LANG=3D"0">Thanks, Father Arp, <BR> <BR> &nbsp;&nbsp;&nbsp;For the very current info and for the beautiffful = [computer-type] figggure of spppeech &lt;BG&gt;. &nbsp;I'd like to hear = what something like this would cost when ready. <BR> <BR>Best Regards &amp; Respectfully, <BR>Roy Kersey <BR> <BR></FONT></HTML>   --part1_189.113b6838.2b0dda6b_boundary--  
(back) Subject: Re: [Residence Organs] Load down discussion From: "John Vanderlee" <jovanderlee@vassar.edu> Date: Thu, 21 Nov 2002 07:58:28 -0800   > >I disagree. Once the resistor is in place, the voltage will be a = constant >12 volts. Simple ohms law tells you that 1.2 amps will flow given 10 = ohms. >This is only 15 watts of heat the resistor will be emitting, a part rated = 20 >should be fine. >HOMEPAGE : http://www.diyapason.pipechat.org >List: mailto:DIYAPASON-L@pipechat.org >Administration: mailto:owner-DIYAPASON@pipechat.org   Sorry , I andwered this before I had my morning coffee. Transposed ohms and amps. The 1.2 amps is correct and the resistor would be fine.   Still I would use the IC instead to regulate several branch circuits and all could be protected by diodes, but the resistor is indeed simpler although wasteful of current.   John V...writing out all permutations of Ohm's Law 120 times    
(back) Subject: Re: [Residence Organs] Re: DIYAPASON-L Digest #687 - 11/18/02 From: "John Vanderlee" <jovanderlee@vassar.edu> Date: Thu, 21 Nov 2002 08:04:43 -0800   >> >> >>I have been following the power supply discussion, and I wonder if = anyone >>has looked at the ASTRON regulated power supplies? > > >I'm running a 30 amp Astron on my 2/5 Wicks and it does a fine job! >(Much better than the old Orglectra selenium rectifier that came >with the beast). I got mine at a hamfest for about $75. Try >www.aesham.com for good prices. > >Dave in Vermont (N1CPP)   Orgelectras can be salvaged by replacing the selenium rectifier with a solid state diode bridge of comparable ratings. Your voltage will go up a bit, but if it has taps you can compensate. or see perevious discussion on higher voltages.   John V    
(back) Subject: Re: [Residence Organs] Load down discussion From: "Eric Sagmuller" <ess4@psu.edu> Date: Thu, 21 Nov 2002 08:20:04 -0500   At 04:37 PM 11/20/2002 -0500, you wrote: >On 11/20/02 11:04 AM, "John Vanderlee" <jovanderlee@vassar.edu> wrote: > > >> Steve, > >> There is a simple solution to your problem. I have built many power > supplies > >> including > >> the one I use on my own organ. Whats happening is the capacitor is > charging > >> to the > >> peak voltage it sees when there is no load on it. A 12 volt supply = means > >> 12volts RMS, > >> however the peak voltage is actually a little over 16 volts. > >> The solution is to add a wirewound resistor across the capacitor, I > suggest > >> approx 10ohms > >> and rated at about 20watts. This should drop your peak voltage back > into the > >> 12-13 volt range.   I just recently built a beefy, unregulated, 30+ amp supply to run my Peterson combination action. This supply was running about 17 volts. = Adding a 20 ohm resistor across the output only dropped the peak voltage down to 16 volts. When the action was operated the voltage only dropped to about = 14 volts with approx. 20 amps being drawn. If the supply drops from 16 volts =   to 12 volts with only 1.2 amps being drawn then it is a very spongy = supply. This is speaking of a capacitor input supply. Some that use chokes may react differently. My stoptabs were running too hard so I added a small buck transformer to get the voltage down to about 13 volts unloaded. Of course I have two large mfd. capacitors in the supply which initially = keeps the voltage from dropping in the first instant that the tabs move.   I plan to obtain an Astron supply when I switch my organ to all electro-mechanical action. As some have stated I think they're the best deal. A combination action only draws a pulse of power, so a capacitor input supply is plenty, and much cheaper, at least for me as I could build = it.