Peter.
Titanium
- Joined
- Mar 28, 2007
- Location
- England UK
I love my 10ee but there's one niggle I am looking to overcome. It seems that my Ohmite has suffered a repair in it's lifetime which means there's a quite significant jump in the rpm as I turn the dial. On inspection it seems that a small portion of the winding has been replaced, probably by copper wire rather than resistance wire but it's in a really annoying spot that makes the motor leap from about 300rpm to about 700rpm.
Now because I use the DC panel in completely standard form I have to keep the Ohmite for field weakening and that half of it work perfectly. The repaired side I use as a simple potentiometer to provide a 0-10v to my drive to control the base speed.
What I would like to do is disconnect the troublesome half of the Ohmite and somehow attach a modern pot to the shaft to use as base speed control. The trouble is that the Ohmite only works (as a variable resistor) on half of its turn but the new pot would work on the full turn which is undesirable.
What I want to know is can I do something to force a normal 10K pot to behave like the Ohmite? I want it to give me 0-10v (as supplied from my regulated 10v supply) over half it's swept range and stay at 10v for the rest of it. It's just a control voltage so a few milliamps required.
Is this possible or must I contrive some kind of mechanical setup?
Now because I use the DC panel in completely standard form I have to keep the Ohmite for field weakening and that half of it work perfectly. The repaired side I use as a simple potentiometer to provide a 0-10v to my drive to control the base speed.
What I would like to do is disconnect the troublesome half of the Ohmite and somehow attach a modern pot to the shaft to use as base speed control. The trouble is that the Ohmite only works (as a variable resistor) on half of its turn but the new pot would work on the full turn which is undesirable.
What I want to know is can I do something to force a normal 10K pot to behave like the Ohmite? I want it to give me 0-10v (as supplied from my regulated 10v supply) over half it's swept range and stay at 10v for the rest of it. It's just a control voltage so a few milliamps required.
Is this possible or must I contrive some kind of mechanical setup?