<div dir="ltr">oh my bad i'm an idiot disregard my last email. :-/<div><br></div><div>minty boost is a "boost converter" which steps up vs. "buck converter" which steps down.</div><div><br></div><div style>
i'm terribly sorry I was just trying to be helpful.</div></div><div class="gmail_extra"><br clear="all"><div><br>nick<br></div>
<br><br><div class="gmail_quote">On Tue, Jan 8, 2013 at 6:01 AM, Nicholas Granado <span dir="ltr"><<a href="mailto:ngranado@gmail.com" target="_blank">ngranado@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr">it might be useful to examine (it was to me) the mintyboost circuit (uses a buck converter). there's a great write up by ladyada here: <a href="http://www.ladyada.net/make/mintyboost/process.html" target="_blank">http://www.ladyada.net/make/mintyboost/process.html</a><div>
<br></div></div><div class="gmail_extra"><br clear="all"><div><br>nick<br></div><div><div class="h5">
<br><br><div class="gmail_quote">On Tue, Jan 8, 2013 at 5:27 AM, Jake <span dir="ltr"><<a href="mailto:jake@spaz.org" target="_blank">jake@spaz.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
For me, when i want a DC stepdown regulator up to an amp or so (maybe two amps) i just grab a cellular phone car charger. They are all the same, a tiny circuitboard inside with a DIP version of the 34063 buck converter.<br>
<br>
up to 14 or 15 volts input, 5 volts output, just drop it in. If you need a different output voltage, just add a resistor across one of the two resistors in the resistor-divider network. If you need more than 15 volts input (up to 40v) just replace the capacitor with a higher voltage (unless it is already rated at least 10% higher than your working voltage).<br>
<br>
If you need more current, and/or want to be able to make buck converters from scratch, the LM2576 is great. There is a fixed 5v-output version (so the only parts you need are inductor, diode, and two capacitors) or a variable output version (add two resistors to select voltage). It's simple enough that you can put it together without a circuitboard if you're in a hurry. Just ask Zach!<br>
<br>
The LM2576 goes up to 40V input, and the LM2576-HV goes up to 60V!<br>
Both can put out THREE AMPS of current.<br>
<br>
<a href="http://www.ti.com/lit/ds/symlink/lm2576.pdf" target="_blank">http://www.ti.com/lit/ds/<u></u>symlink/lm2576.pdf</a><br>
<br>
Garrett, when you mentioned the 7805 you missed that we were talking about PWM-style buck converters, which are up to 90% efficient. A 7805 linear regulator is basically just an automatic resistor which burns up the extra voltage, times the current you're using. So, powering something with 5V from a 15V power source, you're literally burning off twice as much power as you're making use of (33% efficiency).<span><font color="#888888"><br>
<br>
-jake</font></span><div><br>
<br>
Garrett wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
This is better/cheaper for 5V 500mA from 6.5-36V:<br>
<a href="http://www.digikey.com/product-detail/en/V7805-500/102-1709-ND/1828602" target="_blank">http://www.digikey.com/<u></u>product-detail/en/V7805-500/<u></u>102-1709-ND/1828602</a><br>
<br>
And the big brother for 1000mA:<br>
<a href="http://www.digikey.com/product-detail/en/V7805-1000R/102-2178-ND/2352137" target="_blank">http://www.digikey.com/<u></u>product-detail/en/V7805-1000R/<u></u>102-2178-ND/2352137</a><br>
</blockquote>
<br></div><div><div>
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