Minty Boost, output same as input

Ideas and questions about MintyBoost kits

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MercuryRising
 
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Joined: Fri Jan 18, 2008 8:42 pm

Minty Boost, output same as input

Post by MercuryRising »

Okay, so I found the Ziemagination minty boost first. So i bought the parts that he lists. I got the MAX1756 first, but then when it came it was the size of a pea and I can't do that. So I got a Max756, and now I can't get my circuit to work.

http://www.projects.ziemaginations.net/ZMB/ZMB.html


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No idea what's up with it, here is the pinout of the MAX756
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I tried to match them up, the circuit I used doesn't have a 3/5 switch, if it's grounded it goes to 5 correct? I did that, but not working. I don't get any voltages on the 1 pin of the USB port. Batteries register @ 2.5 total. Thanks in advance.

And I'm using 100 uF capacitors, not sure if that's a source of problems or not. 10k resistors. 22uH inductor.

adafruit
 
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Joined: Thu Apr 06, 2006 4:21 pm

Post by adafruit »

you're missing a very important part :)

TheDon125
 
Posts: 23
Joined: Tue Jan 09, 2007 9:58 pm

Post by TheDon125 »

Hey (I'm Ziemaginations btw). Your problem is that, while the circuits are similar, they are not the same. My design does away with the Schottky diode, due to the upgraded design of the MAX1675. If you are going to go with Ladyada's design, you will need to get a Schottky diode and place it in the appropriate portion of the circuit.

And yes, the MAX1675 is quite small and was a pain to solder, but it is certainly possible to do.

Edit 3:
Surprised to see that page is still being found. Admittedly, I should probably take it down, since there are flaws in the design, and the current board/schematic combination is untested.

MercuryRising
 
Posts: 6
Joined: Fri Jan 18, 2008 8:42 pm

Post by MercuryRising »

And it is safe to assume that this Shottky diode is only available online correct? Thanks for the quick replies!

TheDon125
 
Posts: 23
Joined: Tue Jan 09, 2007 9:58 pm

Post by TheDon125 »

As far as I know, Schottky diodes are fairly easy and cheap to find, might even have luck at a local electronics shop. But yes, they are available on the web. Ladyada reccomends http://www.mouser.com/search/ProductDet ... 511-1N5818 that one from mouser or http://www.digikey.com/scripts/DkSearch ... 3%2F1GI-ND that one from digikey. If you must order them, I'd personally go with mouser, as they don't have a service charge like Digikey does for such a small order.

Entropy
 
Posts: 472
Joined: Tue Jan 08, 2008 12:43 am

Post by Entropy »

MercuryRising wrote:And it is safe to assume that this Shottky diode is only available online correct? Thanks for the quick replies!
You can probably get away with a normal rectifier diode temporarily. The Schottky diode has a lower voltage drop than a normal one, which improves efficiency and output current capability.

Should be able to find one at a good electronics shop, possibly even Rat Shack in a pinch.

adafruit
 
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Joined: Thu Apr 06, 2006 4:21 pm

Post by adafruit »

Entropy wrote:
MercuryRising wrote:And it is safe to assume that this Shottky diode is only available online correct? Thanks for the quick replies!
You can probably get away with a normal rectifier diode temporarily. The Schottky diode has a lower voltage drop than a normal one, which improves efficiency and output current capability.

Should be able to find one at a good electronics shop, possibly even Rat Shack in a pinch.
er, not really, they're not fast enough!

Entropy
 
Posts: 472
Joined: Tue Jan 08, 2008 12:43 am

Post by Entropy »

ugh, I should have remembered that!

work is rotting my brain. :)

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