power supply voltage reduction 9v input to two 3v outputs
Hello all !
I'm new to instructables and I’ve found some cool and helpful information for my projects. I need a bit of help designing a power supply voltage reduction device. One that accepts 9v input and output into two 3v 5mA outputs. I want to replace the batteries in a/b Boss selector with a more reliable source of power.
7
comments
|
Add Comment
|
sort by:
active |
newest |
oldest
Dec 1, 2007. 8:58 PMguyfrom7up
says:
wait, why do you want a more "relaible source", two AA's would last way way way longer than 1 9volt battery.
lets say a 9 volt battery has a life of 500mA, 9 x 500mA= 3500wh
lets say a AA has a life of 2000mah, 1.5x2000= 3000wh
so it may appear that a 9volt has more energy but also take this into consideration:
1) a 9volt takes up the same amount of space as 2 AA's, so it's more like 6000wh.
2) the buck circuit for a 9 volt takes up extra space and is complex, or a linear regulator which is simple grossly reduces the battery life.
lets say a 9 volt battery has a life of 500mA, 9 x 500mA= 3500wh
lets say a AA has a life of 2000mah, 1.5x2000= 3000wh
so it may appear that a 9volt has more energy but also take this into consideration:
1) a 9volt takes up the same amount of space as 2 AA's, so it's more like 6000wh.
2) the buck circuit for a 9 volt takes up extra space and is complex, or a linear regulator which is simple grossly reduces the battery life.
With a voltage divider, you would end up with a net loss and about 3.5 v on each side.
Nov 30, 2007. 12:48 PMguyfrom7up
says:
does it have to be exactly 3 volts? You could convert it down extremeley easy to 3.3 volts using a linear regulator
Dec 1, 2007. 8:40 PMtestpartner (author)
says:
That a good question. :) the device that I would like to power takes 2 AAA batteries or better yet here are the specs from the owner manual: Current Draw: 5mA or less Power Supply: Dry Battery(R03 /LR03 (AAA) type ) x 2 Does this help?
Dec 1, 2007. 8:48 PMguyfrom7up
says:
well generally AA's when brand new prouce 1.7 volts, so that would be 3.4 volts, which I think would be fine, I'll draw you up a schematic really quick
 |
Vancouver Mini Maker Faire 2012
Rebuilding NordicTrack ski machine drive rollers
Looking for New Zealand-based Instructables authors for conference on August 27 in Wellington
Call to makers - Brighton Mini Maker Faire
Milk Crates - not as green as you think
TEDxBaghdad - Iraq - violence, dust storms and open sourced manufacturing
UK Mini Maker Faire - The Derby Silk Mill - New Poster to Share!
