Article View: sci.electronics.design
Article #2324Re: Supply for LV lighting application?
From: John Fields
Date: Fri, 14 Mar 2003 21:05
Date: Fri, 14 Mar 2003 21:05
43 lines
3497 bytes
3497 bytes
On Fri, 14 Mar 2003 12:42:21 -0800, DaveC <anon@bugus.net> wrote: >I've been asked to help light a small office building hallway. The >fluorescent lamps are way too harsh for the office workers, and the tenants >favor the overhead QH approach. > >I've looked at the local home centers' lighting departments and see quite a >selection of LV systems using overhead steel cable with 3 hanging reflector >bulbs (with a choice of trim, or not) tapped in at appropriate intervals. > >Price for the above from $70-100us. > >Being encouraged by what I saw, I decided to see what I could build from >scratch. > >As you probably can guess, I'm running into current supply/demand >limitations. Each of the 2 hallways could use about 15 lamps. Lamps are >available in 20 and 50w versions, which at 12v, draw approximately 1.7a and >4.2a, respectively. I now see why the cost of such a system is mostly for the >supply. > >Looking for a ready-made 12v supply, I find this at Jameco for $70us that >provides 12.5a: > ><http://www.jameco.com/cgi-bin/ncommerce3/ExecMacro/Jameco/searchResult.d2w/report?sort=BPA&search=123422 >> > >This would allow me to run 7 of the 20w lamps, or only 2 of the 50w lamps. > >I can't see buying 2 supplies to run the 15 (well, I guess we could rev that >to 14) lamps in each hall. I seem to be butting up against Ohm's Law. > >Maybe build a simple, unreg'd, analog power supply with massive transformer >and rectifiers for 30A? > >Any other ideas (or links to sites) to help me reach a solution would be >greatly appreciated. --- What's QH? Quartz-Halogen? If so why can't you run them on AC? -- John Fields Professional circuit designer http://austininstruments.com
Technical Details
Message-ID:
<9hg47vsjv3ub6ojlcuqppe1osih50e277v@4ax.com>Path:
arc1-ca.pugleaf.net!archiver1.google.com!news1.google.com!newsfeed.stanford.edu!logbridge.uoregon.edu!arclight.uoregon.edu!wn13feed!worldnet.att.net!216.166.71.11!nntp2.aus1.giganews.com!nntp.giganews.com!nntp3.aus1.giganews.com!nntp.texas.net!news.texas.net.POSTED!not-for-mailReferences:
<0001HW.BA977EAD001869E90E6B7920@news.covad.net>Show Full Headers
Complete Article Headers
X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 112d1e,bb2f1d6cc718187b,start X-Google-Attributes: gid112d1e,public X-Google-Thread: 103407,bb2f1d6cc718187b,start X-Google-Attributes: gid103407,public X-Google-Thread: 10d137,bb2f1d6cc718187b,start X-Google-Attributes: gid10d137,public X-Google-Thread: 107cee,bb2f1d6cc718187b,start X-Google-Attributes: gid107cee,public X-Google-ArrivalTime: 2003-03-14 13:05:09 PST Path: arc1-ca.pugleaf.net!archiver1.google.com!news1.google.com!newsfeed.stanford.edu!logbridge.uoregon.edu!arclight.uoregon.edu!wn13feed!worldnet.att.net!216.166.71.11!nntp2.aus1.giganews.com!nntp.giganews.com!nntp3.aus1.giganews.com!nntp.texas.net!news.texas.net.POSTED!not-for-mail NNTP-Posting-Date: Fri, 14 Mar 2003 15:05:06 -0600 From: John Fields <jfields@austininstruments.com> Newsgroups: sci.electronics.design,sci.electronics.misc,alt.engineering.electrical,aus.electronics Subject: Re: Supply for LV lighting application? Date: Fri, 14 Mar 2003 15:05:04 -0600 Organization: Austin Instruments, Inc. Message-ID: <9hg47vsjv3ub6ojlcuqppe1osih50e277v@4ax.com> References: <0001HW.BA977EAD001869E90E6B7920@news.covad.net> X-Newsreader: Forte Agent 1.93/32.576 English (American) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 43 X-Trace: sv3-6R0FdQ5tmjn8Iu7nI7HHBxZrzoicPQ3oMmt8NiWeUV0pRzDVq4UTjLnpPkdw5Q5wLI7MQ6UypDRbetJ!KLzZEb9eki/fqBqUMhVcicYEFob6W6KE/Xd5T9059zqwDbuE7c7LLVMLFUeVk5rCl2q/Qx2V6AQ= X-Complaints-To: abuse@texas.net X-DMCA-Complaints-To: abuse@texas.net X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.1