Push button controlled Potentiometer? How?

[Amps]

Hey guys!

I've spent 3 hours researching different DPPs (digitally programable potentiometers) but everything I find seems too overkill for what I need.

Here's my cicuit idea:

The CPU cooling fan in my computer operates from 3000-7000RPM using a small pot wired into a simple LM317 circuit ranging from 5v to 12v. I want to be able to find an electronically controlled pot that I can control through two momentary switches (up and down).

Is there an IC that someone knows that I can use to do this? If so, would you mind giving me a quick rundown on how to control it and set the range? My electronics knowledge is slim (only grade 10 electronics) but I have a great problem solving mind so if I can get some simplified terms, I can work from there.

Thanks guys!

 

[MP1]

Here, try this. The Dallas digital pots are not that hard to figure. This is an application note from Dallas showing how.

MP

Dalls_Digital_Pots-app69.pdf

 

[mixos1]

Also here :

http://www.electronic-circuits-diagrams.com/audioimages/audiockt11.shtml

you will find a simple use of DS1669 digital potentiometer. The same circuit is here also :

http://www.electronics-lab.com/projects/audio/033/

 

[Amps]

Thats great guys. One question though: What is the resistance range on the DS1669? I can't seem to find it on the data sheet.

<EDIT> Nevermind guys, was looking at the wrong datasheet. Looks like I can get it in a nice 10k flavour </EDIT>

 

[Twizted]

Anyone have a quick diagram of the DS1669 coupled with a op-Amp to control higher current loads than the DPP is capable of? Thanks

 

[Twizted]

well shoot lol.... I thought someone might have replied about a proper opto setup..  :

I think its just a matter of cool and asteticly pleasing application when it comes to the PC.... I am wanting to know for another PC application.... but mine is for controling brightness of LED's which are rated from 30 to 180mA accordingly.. so I would have to use the opto...

 

[audioguru2]

Hi Vernon (Twizted),
You promised to send me some blue LEDs as thanks for the free circuit design I did for you?
You don't reply to my e-mail about it?
???

 

[Twizted]

???
You never got it? I sent it a long time ago  :-\
I never heard from you so I assumed you had gotten it. I havn't gotten any e-mail's

I will build another one and send it again with a way to track it.. UPS delivers to Canada I assume?

USPS is ticking me off I have lost so much money on them loosing stuff the past 6 months

I am sorry man... I will have it out this week and will PM you a Tracking Number...

BTW.... The Case of Hope project it went into was sold. but it didnt go as high as we expected.... but everyone loved the Gem and circuit.

 

[audioguru2]

Thanks, Vernon.
I saw a video of the Case of Hope gem on the web brightly lighting its pink LEDs then dimming. I would have added a heatbeat to it. ;D

 

[Twizted]

The peeps on PR did start calling it the heartbeat of the case..

There was so much that could have been done with it... but as they say ... hind sight is 20.20 hehe....

I am going to have to get back down to my house I apparently had not sync'd the folder that the design was in to my laptop and I am at a friends but I think I should be able to get it out by the weekend...