| To: | garyschafer@comcast.net |
|---|---|
| Subject: | Re: [Amps] Plate transformer current unknown |
| From: | "Angelo Karabetsos" <ve3yn@hotmail.com> |
| Date: | Fri, 06 May 2005 03:11:42 +0000 |
| List-post: | <mailto:amps@contesting.com> |
|
Thanks Gary, Will and all for answering my questions. You learn a thing or
two everyday. Cheers Angelo <br><br><br>>From: Gary Schafer <garyschafer@comcast.net><br>>Reply-To: garyschafer@comcast.net<br>>To: Angelo Karabetsos <ve3yn@hotmail.com><br>>CC: amps@contesting.com<br>>Subject: Re: [Amps] Plate transformer current unknown<br>>Date: Tue, 03 May 2005 11:45:41 -0400<br>><br>>Hi Angelo,<br>><br>>.9 is about what you get with a choke input filter.<br>>With a full wave bridge capacitor input the no load voltage will be <br>>1.414 times. I usually use about 1.25 figure for loaded voltage when <br>>figuring supply output voltage. It will of course vary depending on <br>>how good the transformer is. But it gets you in the ball park.<br>><br>>For a doubler I figure around 2.5 times for loaded voltage.<br>><br>>73<br>>Gary K4FMX<br>><br>>Angelo Karabetsos wrote:<br>>>I am unable to calculate anything to do with windings or core due <br>>>to the fact it is in a metal case encapsulated in black epoxy. I <br>>>discovered this after removing the lid. I'll say one thing, it's <br>>>darn heavy and hard to move around without anywhere to grab. The <br>>>secondary wire gauge looks to be about 18ga and the dimensions are <br>>>11"x9"x10" and has a RCA nameplate. Not too much more information I <br>>>can determine. Now I know what to look for at flea markets.<br>>>One other question. What should the B+ voltage be after <br>>>rectification. Lets say 3000v secondary through a fullwave bridge <br>>>rectifier and a bank of ten 470uf 450v caps? I read somewhere to <br>>>multiply by 0.9 and that should be a good rule of thumb. What I am <br>>>trying to determine is how to calculate the proper transformer for <br>>>the job and keep voltage drop under load to respectable figure. Not <br>>>an easy task to figure out with surplus parts.<br>>><br>>>Angelo<br>>><br>>>&gt;From: &quot;Will Matney&quot; &lt;craxd1@ezwv.com&gt;<br>>>&gt;Reply-To: craxd1@ezwv.com<br>>>&gt;To: amps@contesting.com<br>>>&gt;Subject: Re: [Amps] Plate transformer current unknown<br>>>&gt;Date: Fri, 29 Apr 2005 11:28:25 -0400<br>>>&gt;<br>>>&gt;Angelo,<br>>>&gt;<br>>>&gt;Really you cant tell that way (using the resistance) unless you <br>>>know the mean lenght of turn, how many turns per layer, and how <br>>>many layers they are in the winding. This then would give you how <br>>>long the wire is and you could then use the resistance and the <br>>>length to determine the wire size. If it's possible to use a <br>>>micrometer or a wire gauge to see what the secondary wire size is, <br>>>then one can find out what its rating is. In amateur service, ICAS <br>>>used anywhere from 700 to 900 circular mils per ampere. CCS uses <br>>>anyhwere from say 1000 to 1200 cir. mil. per amp. If you can find <br>>>the wire size, go look at a wire chart for how many circular mils <br>>>it has and divide by the above numbers to determine its current <br>>>carrying ability. IE, 10,000 circular mils running at 1000 cir mil <br>>>per amp = 10 amperes.<br>>>&gt;<br>>>&gt;Best,<br>>>&gt;<br>>>&gt;Will<br>>>&gt;<br>>>&gt;<br>>>&gt;*********** REPLY SEPARATOR ***********<br>>>&gt;<br>>>&gt;On 4/29/05 at 3:01 PM Angelo Karabetsos wrote:<br>>>&gt;<br>>>&gt; &gt;I would like to find out the current rating of a <br>>>transformer. Primary<br>>>&gt; &gt;voltage taps 0v-110v-115v-208v-230v and secondary taps <br>>>3450v-0v-3450v and<br>>>&gt; &gt;secondary resistance of 53.5ohms from 0v to 3450v tap and <br>>>107ohms from<br>>>&gt; &gt;3450v<br>>>&gt; &gt;to 3450v tap. All measurements done with a simple DMM. The <br>>>commercial<br>>>&gt; &gt;amplifier it came out of has a plate current meter with a <br>>>max reading of<br>>>&gt; &gt;600ma. How could I find out the CCS or ICAS rating?<br>>>&gt; &gt;Cheers Angelo<br>>>&gt; &gt;<br>>>&gt; <br>>>&gt;_________________________________________________________________<br>>>&gt; &gt;Take charge with a pop-up guard built on patented <br>>>Microsoft® SmartScreen<br>>>&gt; &gt;Technology<br>>>&gt; <br>>>&gt;http://join.msn.com/?pgmarket=en-ca&amp;page=byoa/prem&amp;xAPID=1994&amp;DI=1034&amp;SU=http://hotmail.com/enca&amp;HL=Market_MSNIS_Taglines<br>>><br>>>&gt; &gt; Start enjoying all the benefits of MSN® Premium right <br>>>now and get the<br>>>&gt; &gt;first two months FREE*.<br>>>&gt; &gt;<br>>>&gt; &gt;<br>>>&gt; &gt;_______________________________________________<br>>>&gt; &gt;Amps mailing list<br>>>&gt; &gt;Amps@contesting.com<br>>>&gt; &gt;http://lists.contesting.com/mailman/listinfo/amps<br>>>&gt;<br>>>&gt;<br>>>&gt;<br>>>&gt;_______________________________________________<br>>>&gt;Amps mailing list<br>>>&gt;Amps@contesting.com<br>>>&gt;http://lists.contesting.com/mailman/listinfo/amps<br>>><br>>>_________________________________________________________________<br>>>Don't just Search. Find! <br>>>http://search.sympatico.msn.ca/default.aspx The new MSN Search! <br>>>Check it out!<br>>><br>>><br>>>------------------------------------------------------------------------<br>>><br>>>_______________________________________________<br>>>Amps mailing list<br>>>Amps@contesting.com<br>>>http://lists.contesting.com/mailman/listinfo/amps<br>><br>><br>><br> _________________________________________________________________ Take advantage of powerful junk e-mail filters built on patented Microsoft® SmartScreen Technology. http://join.msn.com/?pgmarket=en-ca&page=byoa/prem&xAPID=1994&DI=1034&SU=http://hotmail.com/enca&HL=Market_MSNIS_Taglines Start enjoying all the benefits of MSN® Premium right now and get the first two months FREE*. _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps |
| <Prev in Thread] | Current Thread | [Next in Thread> |
|---|---|---|
| ||
| Previous by Date: | [Amps] Receiving lower spec items than ordred., David Kirkby |
|---|---|
| Next by Date: | Re: [Amps] Input Impedance of RF MOS amp, Stefan |
| Previous by Thread: | Re: [Amps] Plate transformer current unknown, Gary Schafer |
| Next by Thread: | Re: [Amps] Plate transformer current unknown, Will Matney |
| Indexes: | [Date] [Thread] [Top] [All Lists] |