Before I go off and fab out what should be a simple task I'll ask here. I would like to buy ready made an analog PID that is small in board size, use existing +/- 10/15 VDc supply from the device and support a minimum of Gain and Lead. It can have other things like Lag and maybe break support... What I really need only involves a couple of op-amps/comparators to create a LEAD signal for a reference from a potentiometer that is on a small board that can fit inside a drive enclosure to be connected to the analog input for speed control.
These drives, whichwe have a lot of on a piece of equipment, do not have a full PID control system. We need a LEAD function which exist on other boards that perform PID functions how ever, those boards are fully stand alone and to large to fit inside..
This is just a simple thing like a LM324 stage using a voltage follower with a capacitor Leading on the output and another stage to buffer it.. We need to add this control to the drives to give a LEAD function to stop an oscillation problem we have due to a short physical range the catenary arm has..
Before I go and fab out a board with this design, would like to know if something small on a board that can be tucked in side exist ?
I would use the +/- reference voltages supplied from the drive to power the board and wiper of the pot would drive this board while the output of this board would drive control signal for the drive it self. It's hard to believe that we replaced a few drives with much newer technology that was being used. We still have a few older drives working on this machine and they work perfectly well and the technology in these drives are so old and minimum in design it isn't funny but yet, they perform perfectly with this application.
After close examination, we found that the only thing they have going for them is, they have a capacitor lead circuit which resolves the problem perfectly. I am inclined to think that maybe theses drives were specially designed for this job. I've never seen these units any were else that contain only a lead function with no other PID options other than an offset to set the position of the catenary arm.