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Author Topic: Making my own SEPIC dc/dc converter  (Read 2102 times)

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Offline z.s.tar.gzTopic starter

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Making my own SEPIC dc/dc converter
« on: January 15, 2010, 04:06:32 PM »
In this next chapter of my seemingly never ending quest to use solar charging with lifepo4 batteries, I need to make my own sepic converter circuitry.
I've been reading all the sites I can find on google, and I pretty much understand how they work, but I still have a few questions.

1. What do you use for the switcher? There are IC's for it, but they're all surface mount (which I don't have to tools to work with). Wikipedia also mentions using a mosfet transistor, but I don't understand how that can do switching.

2. Where is a good place to get formulas so I can calculate what parts I need? Lots of sites talk about the theory behind it, but don't actually give how to calculate for one.
Save yourself the typing. Just call me Zach.

Offline little-c

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Re: Making my own SEPIC dc/dc converter
« Reply #1 on: January 15, 2010, 04:52:58 PM »
mosfet, h bridge tutorial says how they work.


do you get transistors?

a mosfet is a transistor. at least in effect.

basicly a current on the input (collector)pin drops the risistance, and lets current flow through the device(base and emitter pins)

horrible math/physics/chemistry stuff behind it, but don't bother with that ;)


Offline z.s.tar.gzTopic starter

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Re: Making my own SEPIC dc/dc converter
« Reply #2 on: January 15, 2010, 05:02:49 PM »
Ok, I get how the transistor works now (or at least I think)
This just leaves the eqations...
Save yourself the typing. Just call me Zach.

Offline Soeren

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Re: Making my own SEPIC dc/dc converter
« Reply #3 on: January 16, 2010, 09:08:43 AM »
Hi,

1. There are IC's for it, but they're all surface mount (which I don't have to tools to work with).
I linked you to a through hole SEPIC-able switcher IC a while ago!


Wikipedia also mentions using a mosfet transistor, but I don't understand how that can do switching.
They're used as the power switch, driven by a switch mode IC.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline z.s.tar.gzTopic starter

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Re: Making my own SEPIC dc/dc converter
« Reply #4 on: January 16, 2010, 09:24:46 AM »
That works for sepic too?
I thought it was only a linear regulator...

Well now I just feel like a noob. :P

Edit: I was looking at the wrong post... Facepalms all around.

the LT1513 is exactly what I needed, thank you very much. (even if it took forever for me to realize it)
« Last Edit: January 16, 2010, 11:33:49 AM by z.s.tar.gz »
Save yourself the typing. Just call me Zach.

 


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