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MAX756 question
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Please be positive and constructive with your questions and comments.

MAX756 question

by smeezekitty on Thu Mar 25, 2010 3:12 pm

I have made a home made wind generator that output usually between ~.8v to 4v DC @ 100MA +.
Can i connect this output to a MAX756 to run a small 3v radio?
smeezekitty
 
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Re: MAX756 question

by zener on Fri Mar 26, 2010 2:48 am

How much current does the radio use at 3V?

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Re: MAX756 question

by smeezekitty on Fri Mar 26, 2010 3:17 am

About 75MA.
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Re: MAX756 question

by CharlieD on Sat Mar 27, 2010 11:55 am

The data-sheet fir the '756 shows 300mA @3v3, so you should be good to go ...
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Re: MAX756 question

by smeezekitty on Sat Mar 27, 2010 5:00 pm

Ok...thanks.
smeezekitty
 
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Re: MAX756 question

by zener on Sat Mar 27, 2010 5:46 pm

Ummmm, keep in mind that you have to have enough current IN to supply the current OUT. The input current is multiplied in relation to the boost. For example if you put out 3V at 75 mA and your input voltage is 1.5 then you need 150 mA IN, PLUS more to make up for inefficiency. So for example if the efficiency is 80% then you need to add another 25% so that means 188 mA in. It is quite possible that your generator cannot put out 188 MA at 1.5V. So you really need to know what voltage and current (at the same time) the windmill can put out. Another thing to consider is what is the minimum voltage the radio will work at, and what is the maximum. You might be better off just hooking the radio straight to the generator, or adding a small rechargeable battery to the circuit to even things out.

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Re: MAX756 question

by smeezekitty on Sat Mar 27, 2010 5:50 pm

Connecting the radio direct does not work as it frequently drops below 2 volts.
It can provide 200ma at 1.5 v at moderate wind (we are in stormy area).
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Please be positive and constructive with your questions and comments.