Mike, Thanks for your suggestion. DC-DC converter module (which will compact) will atleast cost $17-18,but I need this soln for $4-5.Power consumption from the input side is not much concern for me right now.Also don't want a bulky solution.(SMPS).I am looking for some forward converter.If you have anything in your knowledge let me know. Thanks & Regards, Mahesh ----- Original Message ----- From: "Mike Brown" <bmgman@xxxxxxxxxx> To: <mahesh@xxxxxxxxxx> Cc: <si-list@xxxxxxxxxxxxx> Sent: Friday, March 12, 2004 11:04 AM Subject: Re: [SI-LIST] Power Supply > Mahesh, > > this sounds like it could be a case of "save money at any cost". You > are going to burn 48 watts of 48 volt power to deliver 12 watts of load > power. Those 36 watts are not free. A DC Converter at 75% efficiency > (and I know that you can do better than that!) burns 16 watts from 48 > volts. So if the converter costs less than 20 watts of 48 volt power > delivery, it is actually saving money. > > This is overly simplistic, since the 48 volt power may already be paid > for - hence virtually "free". > > However, the 20 watt difference will impact the temperature in your box, > and the cooling impact may not be free. > > There may be regulatory pressure to isolate the 48 volts from the 12 > volt side for safety reasons, in which case you have no choice but an > isolated converter. > > Regards > > Mike > > Mahesh Linge wrote: > > > Hi Grp, > > > > Can Any one tell me the solution for Power supply design for 48 volt to 12 > > volt(1 Amp).I am looking for a descrete solution.I dont want to use a DC-DC > > converter in this design due to cost constraints. > > > > Hope some one from group will come up with better solution. > > > > Thanks in advance. > > > > Mahesh > > > > ------------------------------------------------------------------ > > To unsubscribe from si-list: > > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > > > > or to administer your membership from a web page, go to: > > //www.freelists.org/webpage/si-list > > > > For help: > > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > > > List technical documents are available at: > > http://www.si-list.org > > > > List archives are viewable at: > > //www.freelists.org/archives/si-list > > or at our remote archives: > > http://groups.yahoo.com/group/si-list/messages > > Old (prior to June 6, 2001) list archives are viewable at: > > http://www.qsl.net/wb6tpu > > > > > ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu