Boost conversion

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tridentsx
 
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Boost conversion

Post by tridentsx »

I am looking for information/circuit examples about boost conversion.

I want to be able to boost 5v from USB all the way up to 25v in small steps and have it s/w controlled by an MCU. What is the best/simplest way to implement this ?

-- Always boost to 25v and then regulate it down with a DAC controlled transistor ?
-- Control the boost circuit somehow by outputting different frequency from the MCU?
-- Other ways of achieving same goal ?

I would also like to know how to use the ADC to measure current to implement a shut off if a certain current level is exceeded. Would I do that by measure voltage drop over a shunt ?

I am working an an universal device programmer and this is the part I am getting stuck at generating the VPP :?:

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zener
 
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Re: Boost conversion

Post by zener »

-- Always boost to 25v and then regulate it down
Yes, with a MAX629 or similar
with a DAC controlled transistor
Something like that
-- Control the boost circuit somehow by outputting different frequency from the MCU?
You could, but that is probably a lot more difficult
-- Other ways of achieving same goal ?
I am sure there are many!
Would I do that by measure voltage drop over a shunt ?
You could, high-side shunt, low-side shunt. You could also look for the voltage dropping out.

tridentsx
 
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Joined: Mon Nov 26, 2012 3:22 pm

Re: Boost conversion

Post by tridentsx »

Thanks a lot for pointing me in the direction of the max629, have ordered a few for testing.

Carl

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adafruit_support_bill
 
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Re: Boost conversion

Post by adafruit_support_bill »

You can also look at the design page of the Ice Tube clock. That has a boost-converter circuit to drive the VFD display.

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