http://www.maximintegrated.com/en/p...onverters/digital-potentiometers/MAX5490.html
To use digital pots in a ckt. that counts up from 0 Ohms to 1.5 megohms in increments relative to a clock. Reverses the cycle then repeats the time constant is 2.3 seconds per ohm increase,

 

The part in your link is simply two resistors. No clock, no counting up or down, and nothing near 1.5 M. Is part of your post missing, because I don't see a question in there?

ak

 

Hello Wayne Gur

You'll need as many chips, MAX5490, as Increments You want between 0 Ohms to 1.5 Megohms.

The MAX5490 single chip contains two high precision resistors connected in series

 

well all I wanted is a linear increment 2.3 ohms/second going to a divider @ 100 K ohms that's about thirty of the ICs. Problem is the controlling circuit and accuracy is another thing.

 

The part in your link is simply two resistors. No clock, no counting up or down, and nothing near 1.5 M. Is part of your post missing, because I don't see a question in there?

ak

yes it is missing first time here mistake I wanted to make a counter up and down