<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=utf-8"><meta name=Generator content="Microsoft Word 15 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Consolas;
panose-1:2 11 6 9 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif;
color:black;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:#FFB300;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:#D7FF00;
text-decoration:underline;}
pre
{mso-style-priority:99;
mso-style-link:"HTML Preformatted Char";
margin:0cm;
margin-bottom:.0001pt;
font-size:10.0pt;
font-family:"Courier New";
color:black;}
p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph
{mso-style-priority:34;
margin-top:0cm;
margin-right:0cm;
margin-bottom:0cm;
margin-left:36.0pt;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif;
color:black;}
p.msonormal0, li.msonormal0, div.msonormal0
{mso-style-name:msonormal;
mso-margin-top-alt:auto;
margin-right:0cm;
mso-margin-bottom-alt:auto;
margin-left:0cm;
font-size:11.0pt;
font-family:"Calibri",sans-serif;
color:black;}
span.EmailStyle19
{mso-style-type:personal;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.HTMLPreformattedChar
{mso-style-name:"HTML Preformatted Char";
mso-style-priority:99;
mso-style-link:"HTML Preformatted";
font-family:Consolas;
color:black;}
span.EmailStyle23
{mso-style-type:personal-reply;
font-family:"Calibri",sans-serif;
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]--></head><body bgcolor=white lang=EN-NZ link="#FFB300" vlink="#D7FF00"><div class=WordSection1><p class=MsoNormal><span style='color:windowtext;mso-fareast-language:EN-US'>You are right, I read Amps instead of Watts, my bad. <o:p></o:p></span></p><p class=MsoNormal><span style='color:windowtext;mso-fareast-language:EN-US'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US style='color:windowtext'>From:</span></b><span lang=EN-US style='color:windowtext'> Chchrobotics <chchrobotics-bounces@lists.ourshack.com> <b>On Behalf Of </b>Mark Atherton<br><b>Sent:</b> Friday, 8 March 2019 12:36 p.m.<br><b>To:</b> chchrobotics@lists.ourshack.com<br><b>Subject:</b> Re: [chbot] Scrounging for big switch mode PSUs<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>3 x 1kw units in either parallel or series will still produce 1 x 3kw<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>-Mark<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>On 8/03/2019 11:45 AM, Wes Edwards wrote:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><p class=MsoNormal><span style='mso-fareast-language:EN-US'>Hi Peter</span><o:p></o:p></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'> </span><o:p></o:p></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'>Wouldn’t 3 x 1000W @48V units produce either 1kW @ 144V (series) or 3kW @48V (parallel)? I don’t think you could get 3kW@114V unless you had 9 units (3 banks in series, with each bank paralleled)?</span><o:p></o:p></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'> </span><o:p></o:p></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'>In any case, I have serious doubts that you can combine PSUs like that either in series or in parallel –you can’t guarantee that the load would distribute evenly – it is more likely that one unit with very slightly different specs would end up taking more load and fail (possibly spectacularly). I think PSUs are very unlike batteries in this regard.</span><o:p></o:p></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'> </span><o:p></o:p></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'>There may be some exceptions with PSUs that are specifically designed to do this, or specialised control electronics to manage the load sharing, but I don’t know of any.</span><o:p></o:p></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'> </span><o:p></o:p></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'>Wes</span><o:p></o:p></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'> </span><o:p></o:p></p><p class=MsoNormal><b><span lang=EN-US>From:</span></b><span lang=EN-US> Chchrobotics <a href="mailto:chchrobotics-bounces@lists.ourshack.com"><chchrobotics-bounces@lists.ourshack.com></a> <b>On Behalf Of </b>Peter Harris<br><b>Sent:</b> Friday, 8 March 2019 10:22 a.m.<br><b>To:</b> <a href="mailto:chchrobotics@lists.ourshack.com">chchrobotics@lists.ourshack.com</a><br><b>Subject:</b> [chbot] Scrounging for big switch mode PSUs</span><o:p></o:p></p><p class=MsoNormal> <o:p></o:p></p><div><div><p class=MsoNormal>Hi All<o:p></o:p></p></div><div><p class=MsoNormal>As part of my domestic grid tied battery system I need an isolated DC power supply capable of producing 2.5kW at between 120V & 300V The voltage does not need to be adjustable.<o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><div><p class=MsoNormal>My plan is to purchase 3 x 1000W 48V caged units and series them to yield 3kW @ 144V however I thought I'd see what folks have gathering dust before I place the order. There a many configurations that would do the trick 2 or 3 x 76V or 96V or even a stack of meaty 24V units.<o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><div><p class=MsoNormal>If you have a suitable combination you would like to dump, sell or swap for beer please let me know.<o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><div><p class=MsoNormal> Peter<o:p></o:p></p></div></div><p class=MsoNormal><br><br><o:p></o:p></p><pre>_______________________________________________<o:p></o:p></pre><pre>Chchrobotics mailing list <a href="mailto:Chchrobotics@lists.ourshack.com">Chchrobotics@lists.ourshack.com</a><o:p></o:p></pre><pre><a href="https://lists.ourshack.com/mailman/listinfo/chchrobotics">https://lists.ourshack.com/mailman/listinfo/chchrobotics</a><o:p></o:p></pre><pre>Mail Archives: <a href="http://lists.ourshack.com/pipermail/chchrobotics/">http://lists.ourshack.com/pipermail/chchrobotics/</a><o:p></o:p></pre><pre>Meetings usually 3rd Monday each month. See <a href="http://kiwibots.org">http://kiwibots.org</a> for venue, directions and dates.<o:p></o:p></pre><pre>When replying, please edit your Subject line to reflect new subjects.<o:p></o:p></pre></blockquote><p><o:p> </o:p></p></div></body></html>