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Topic: solved: "invert" thermistor/Hacking Buck Converter for temp dependent output? (Read 2245 times) previous topic - next topic

raschemmel

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and I located the resistor that is used for the other half of the voltage divider.
Pretty vague description. That's not going to be much help to anyone else trying to do the same thing.
Are you referring to R2 ? If so, wouldn't it be a good idea to mention that ?
MP1584

wothke

Pretty vague description. That's not going to be much help to anyone else trying to do the same thing.
Are you referring to R2 ? If so, wouldn't it be a good idea to mention that ?
MP1584
well, I am not sure if the example schematic of the chip manufacturer is all that useful.. but yes, R2 would be the resistor that I replaced using my 50kOhm thermistor and I also replaced R1 - so that I'd get the desired voltage range for my fan..

Depending on the specific PCB you'll start from the FB pin and locate the resistors of the voltage divider (R1/R2). Here as an example what that meant for the buck converter that I am using:


raschemmel

Don't see any example but I think you explained it sufficiently ( meaning you choose an R1 value to match your thermister such that the FB voltage is correct for your application.)

wothke

Don't see any example but I think you explained it sufficiently ( meaning you choose an R1 value to match your thermister such that the FB voltage is correct for your application.)
I had made a typo in the img tag - but thanks to the bloody forum configuration I had to wait 5 minutes before I was allowed to correct it..  :-(

raschemmel

It must be a "newbie" restriction because I edit my posts whenever I want .

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