[byplane]

I'm working on a var feed system for a something like a planer. It's more elaborate than that, other activities involved. Nonetheless, what I would like to do is monitor the amp draw on the machine. Then use that to control the feed speed. i.e. as the load gets higher the amp draw will raise and, via my imaginary board, will decrease the speed. What I have so far is a Minarik mm23000 drive running a 90vdc motor. The drive has, among other things, a speed pot. What I imagine is a board, similar to a breakout board, that will monitor the amperage and output something that that would parallel or simulate the pot. I contacted Minarik and basically was told it can't be done. Since I already have a working setup I rather not convert to a VFD since I don't think it would be much different that what I have anyway.
Thanks for any thoughts or ideas.

[he1957]

Without any specifics, if the motor speed is controlled by a pot, the pot could be replaced with a digital pot:

https://en.wikipedia.org/wiki/Digital_potentiometer

https://www.maximintegrated.com/en/a...ex.mvp/id/4051

The current drawn could be used as a voltage reference to control the project described.

There may well be a suitable chip that can take a direct digital input rather than needing programming. If there is, then the current draw/voltage analogue signal could be fed to a A/D converter and that digital output could be used to feed the digital pot. There may also be a chip than can take analogue current sensing input but I don't know off-hand.

Another option might be to use current sensing to drive a small servo motor (used in model cars/planes) and that could control the existing pot mechanically.

Just a few thoughts.

[byplane]

Without any specifics, if the motor speed is controlled by a pot, the pot could be replaced with a digital pot:

https://en.wikipedia.org/wiki/Digital_potentiometer

https://www.maximintegrated.com/en/a...ex.mvp/id/4051

The current drawn could be used as a voltage reference to control the project described.

There may well be a suitable chip that can take a direct digital input rather than needing programming. If there is, then the current draw/voltage analogue signal could be fed to a A/D converter and that digital output could be used to feed the digital pot. There may also be a chip than can take analogue current sensing input but I don't know off-hand.

Another option might be to use current sensing to drive a small servo motor (used in model cars/planes) and that could control the existing pot mechanically.

Just a few thoughts.

Awesome ideas. I never considered a servo. And thanks for the links.