±10 from 3.3 volts

FredBlais

I'd like to generate ±10 volt reference that would connect to a motor speed input. I know I can get an analog voltage from 0 to 3.3 with pwm from the prop pin... but how do I scale that? (transistors? chip?)
0 -> -10
1.67 -> 0
3.3 -> 10

thanks!

mctrivia

you will need to create a buck boost converter.

http://en.wikipedia.org/wiki/Buck–boost_converter

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propmod_us and propmod_1x1 are in stock. Only $30. PCB available for $5

Want to make projects and have Gadget Gangster sell them for you? propmod-us_ps_sd and propmod-1x1 are now available for use in your Gadget Gangster Projects.

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mctrivia

the Analog Device Inc ADP1610ARMZ-R7 will give you up to 12V output from a 3.3V source.

Linear Technologies LT3582EUD-12#PBF can give you +-12V from 3.3V but it is a qfn chip.

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propmod_us and propmod_1x1 are in stock. Only $30. PCB available for $5

Want to make projects and have Gadget Gangster sell them for you? propmod-us_ps_sd and propmod-1x1 are now available for use in your Gadget Gangster Projects.

Need to upload large images or movies for use in the forum. you can do so at uploader.propmodule.com for free.

Nick Mueller

You should look for *signed* PWM. No chip-number at hand, sorry.

Doing it with an offset is quite unsafe if you intend to drive a servo. If the PWM is switched off, that would result in a -10V full output.
With signed PWM and no PWM-signal you get 0V. That's much safer! Think what happens during the time the Prop boots up.


Nick

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Never use force, just go for a bigger hammer!

The DIY Digital-Readout for mills, lathes etc.:
YADRO

FredBlais

Hey thanks guys, it·gave me some chip ideas [noparse]:)[/noparse]