Control to terminate power at an Encoder step??

[btcoutermash]

All,
I am sorry, but I am a bit electronics challenged. I was hoping someone could point me in the right direction on this??
What I was trying to accomplish was this.. I wanted to have a unit that by reading a rotary encoders steps, would stop an electric pump when it had reached a predetermined step, or degree.
So the control unit would have the ability to have a degree entered, like 45°, or if one step was a degree, 45. So when the encoder reached that step it would power off an electric pump.

Would anyone have any ideas or examples of how I could accomplish this? I was hoping to get info on some purchase control that would allow me to do this.

Thank You

 

[rovineye]

Are you using a VFD? Step motor?

 

[rovineye]

Stepping controllers can send out a command or pulse to tell the motor to rotate a give amount. It won't know if the motor actually ended up in that position (it only counts commands) unless there is an encoder on the motor to feedback the position.

It also depends on what the application is. If speed, torque, time, or any other variable is importatnt to the process, a vector drive could be used.

 

[waross]

Is this a hydraulic pump,with a hydraulic cylinder causing the rotation?
respectfully

 

[btcoutermash]

Yes, This would be a hydraulic pump with a hydraulic cylinder. Its actually something I am trying to garage engineer onto a bender...

 

[OperaHouse]

There are a lot of up down counters that will stop at a count. More advanced ones will allow entry of a multiplier factor so you can read actual degrees. Another option would be to use a potentiometer and measure voltage on a meter. Correct selection of resistors would make this direct reading. Comparing this with another voltage and you can stop when the values are th same.

 

[waross]

I like to keep it simple. I would use simple limit switch and set a mechanical stop to activate the limit switch. You know, the Kiss principle, Keep It Simple Sam.
I am thinking primarily of a pipe bender. If I had a rebar bender I may use the encoder, hidden inside the machine out of harms way.
respectfully

 

[OperaHouse]

An ebay seller has a couple new Durant E4148794 counters for under $30. These would perform that function nicely with scaling, but you would have to reset them after each bend because I don't think they are up/down. That also means it would have to be a continuous bend without backing off. It does have two presets you can store in memory. This is at least an example of what you should be looking for. Try to find one that lists up/down capability.

 

[MikeHalloran]

Got a _really_ old computer that still works? This would be a natural job for it. Even an original PC is overkill.




Mike Halloran
Pembroke Pines, FL, USA