[sdiy] Digital Pots

[Harry Bissell Jr]

Check the voltage levels they can be used at. MOST
are 5V supply (or less).

The one that Analog Devices lists as +/-15V is more
properly called a multiplying DAC

Putting a resistor in parallel will change the
'taper' of the pot. It will not be linear anymore.
This could be a 'bug' or a 'feature' depending on if
you like the effect.

H^) harry

--- Jeff Farr <moogah at gmail.com> wrote:

> SO, while scouring the net for a way to connect a
> MIDIBox SEQ to a 808
> clone so that all the parameters are digitally
> controlled I've come
> across a series of IC's at analog devices and
> maxim-ic called digital
> potentiometers.  There is a large variety of them in
> many different
> resolutions, of specific interest are the ones with
> 127 possible
> values.  Has anybody tried to use these as an in
> between from encoders
> + digital interface to regular VC circuits?  Some of
> them are 2
> terminal and are listed as , but others have three
> which would seem
> ideal.
> 
> Quote from site:
> "The AD5247 provides a compact 2 mm x 2.1 mm
> packaged solution for 128
> position adjustment applications.
> 
> This device performs the same electronic adjustment
> function as a
> mechanical potentiometer or a variable resistor. The
> low temperature
> coefficient makes this device ideal for high
> accuracy and stability
> variable resistance adjustments. "
> 
>
http://www.analog.com/en/subCat/0,2879,761%255F797%255F0%255F%255F0%255F,00.html
> 
>
http://www.analog.com/en/prod/0,,761_797_AD7376%2C00.html
> 
> Seems with such a selection there should be at least
> one that will
> work.  There aren't alot of available resistance
> values, but if I'm
> not mistaken I can place it in parallel with a
> regular resistor to
> achieve the desired range through 1/Rt = 1/R1 + 1/R2
> etc.
> 
>