Comments on: April 30, 2008 http://www.redecho.org/2008/04/30/435/ my life, reflected and filtered Sat, 11 Oct 2008 02:16:51 +0000 http://wordpress.org/?v=2.0.5 by: mars http://www.redecho.org/2008/04/30/435/#comment-1169 Fri, 02 May 2008 05:58:59 +0000 http://www.redecho.org/2008/04/30/435/#comment-1169 The components will be less than an inch away from the battery pack - this is all going into a little backpack about 5" square. I think weight is more of a concern than battery life - I only need a charge to last about 6-7 hours. Then again it would be fun to throw some high-intensity LEDs in, so pretty soon we're up to 300-400 mA, and now we're just barely lasting 6 hours... okay, yeah, more batteries. 9V is a nice convenient level for LED circuits anyway. The components will be less than an inch away from the battery pack - this is all going into a little backpack about 5″ square. I think weight is more of a concern than battery life - I only need a charge to last about 6-7 hours. Then again it would be fun to throw some high-intensity LEDs in, so pretty soon we’re up to 300-400 mA, and now we’re just barely lasting 6 hours… okay, yeah, more batteries. 9V is a nice convenient level for LED circuits anyway.

]]> by: Lewis Gardner http://www.redecho.org/2008/04/30/435/#comment-1167 Thu, 01 May 2008 05:49:57 +0000 http://www.redecho.org/2008/04/30/435/#comment-1167 Should work. The Integrated Switching Regulator will be less than 85% efficient at 100mA so you will be drawing a bit more current than you think. The only place I see the PT5040 in stock is Digikey. They also have the 100uF 50V electrolytic cap which is all that is really needed if the batteries and 100uF are close to the Integrated Switching Regulator. search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=PT5049A-ND search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=P5571-ND They charge $5 for orders under $25 so might want to add some more stuff to your order. Using a 6 AA pack might be a considerable improvement in runtime. I use bunches of NiMH cells like these www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=247 Looks like a cool project. Should work. The Integrated Switching Regulator will be less than 85% efficient at 100mA so you will be drawing a bit more current than you think.

The only place I see the PT5040 in stock is Digikey. They also have the 100uF 50V electrolytic cap which is all that is really needed if the batteries and 100uF are close to the Integrated Switching Regulator.

search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=PT5049A-ND
search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=P5571-ND

They charge $5 for orders under $25 so might want to add some more stuff to your order.

Using a 6 AA pack might be a considerable improvement in runtime. I use bunches of NiMH cells like these www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=247

Looks like a cool project.

]]> by: Geoff http://www.redecho.org/2008/04/30/435/#comment-1165 Wed, 30 Apr 2008 21:51:57 +0000 http://www.redecho.org/2008/04/30/435/#comment-1165 I bet Simon would know all about this stuff. I bet Simon would know all about this stuff.

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