I want to control variable resistances (2-10-50-100K, 1MOhm) in circuits via my computer (replace a pot by a software control).
I have read about how to wire a potentiometer but in my case I have circuits powered at 9v and 12v (and with double power 9v/-9v/0v …) …
There used to be digital potentiometers up to 15v in DIP (Dual Inline Package), but they seem discontinued…
I suppose there is a case-by-case solution without using digital pots: I have 2 chaos generators circuits (see attached images) where i need computer control over the potentiometers.
The one called chua is more simple, there is only one variable resistance to control (1.5 or 2k):
The one called Jerkster is more complex with several variable resistances (R14,R21,R24,R2,R22):
Any solutions for these examples? Any digital pot in DIP package with up to 12v operation available? Any examples with schematics are very welcome!
Top circuit. You have Pos 9V to pin 8 and pin 4 of the IC. Not going to get far with that.
I think I can see a very tiny negative sign in front of the 9 on the bottom battery but it would be much more obvious if the battery symbol was inverted. That is being a bit picky I know but it does stand out and the minus sign is almost invisible.
The 1k5 is shown as a variable resistor or could be a potentiometer wired as a variable resistor or rheostat
The bottom circuit has 2 pots wired as rheostats. I don’t know a great deal about digital potentiometers but my main concern would be if they can be used in this manner. You would need to do a bit of research on that one. Maybe other contributors may know more as I personally have not used one.
I am sure Mosfets can be used as variable resistors but I don’t know how touchy they are. My personal home grown use for these devices is on/off switches. Once again some research required.
What sort of control and resolution do you require of the potentiometers (3). Physical pots can be quite fine, especially the multi turn variety but digital pots would have to be switched resistance values. Maybe different ones have different increments . This would depend on the bit capability. Element 14 would be a good starting point as they publish data sheets for almost everything they stock and the filters are quite good once you get an idea of what you need.
I may do some research on using Mosfets as variable resistors and digital potentiometers for my own interest but won’t be for a time yet.
PS. Another option could be small motorised potentiometers as used in some audio fader type equipment. or even pots coupled to tiny stepper motors. Pots coupled to servos may be a good option as their approximate position would be known and they are relatively easy to drive.
8 pin dip pots if your still looking in au…
rs are hard to order over the phone you have to go through the interpreter who will lead you to their part code…if online you’ll prolly be ok if they have what your looking for…that is to say…
there are many … that is the first page i found …rs are dear but if you want au gear from them their a bit pricey…
if so take your pick may i ask the exact part number digital pot that your looking for…???
if so just browse the part applications and example circuit
hinking just a simple multi cded pwm program like have an entry per pot u need to adjust…etc…etc,there are coders here or look into Arduino maybe …hope this helps