Powering with 4.8V

Overmind

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Jan 16, 2019
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I encountered a problem from someone: he wants to use li-ion cells to power a small motor that works at 4.8V.
Problem is that a single cell would be too low and 2 in series would be too high.

I'm thinking of recommending him using 2 cells in series andsomething like this:

http://www.datasheetcafe.com/mp23070n-datasheet-buck-regulator/

The objective is to have as little loss in the conversion as possible. Is that good or are there better solutions ?
 
As long as you have plenty of margin with the motor's anticipated current draw (especially when starting & loaded), this should be fine.
 
The buck listed can do 4A peak current. So you will definitely need to make sure of your surge current on the motor. You might be able to parallel two of these together with diodes to keep backflow into the other chip, though (not certain of this though).
You could also build a buck converter with a nano, some FETs, diodes, and inductors. Julian Ilett did this with his MUPPET build. Altho, I'm not sure of it's current capability, been a while since I've watched those vids.
 
Some 7805 will do the trick?
The 5 amp i mean not the 1 amps, keep it simple.
They even have ready to build schematics, for extra amp and lower volt adjustment.
(not even needed), just use two capacitors at the line plus in(33uf) and one on the plus line out(0.1uf)
gnd is gnd
He will be fine.

or
+ 1 on Korishan


The best i could do for now:
http://www.datasheetcatalog.com/datasheets_pdf/L/7/8/0/L7805CT.shtml
Could not upload the proper pdf, sorry.
This is the quickest link i could find that came in the neighborhood of what your friend must have
And i won't send you one of my data books :angel: :angel:

With best regards
 
100kwh-hunter said:
Some 7805 will do the trick?
The 5 amp i mean not the 1 amps, keep it simple.

The 780x regulators are linear type devices& dissipate some serious heat = less efficient
Most are rated about 1A
Something like aLM2576 would give a fixed 5V @ 3Aoutput & is simple to build with.
 
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