Help me select an electric motor control

[polarized]

ne555 servo motor

Hello everybody!

I have a problem and would like to ask if someone of you has an idea. I have a role of paper wrapped around an axle and would like to transfer this role of paper to another axle. The speed of transfering should be slow. For example one meter per one second. I should also be able to stop the transfer every once a wild and to start the transfer again. How many electric motors should I use, what kind of motors, what mechanical components(reductors)etc...? Anyone has an idea???
Thanks.

 

[Hardwarekiller]

paper detector motor control

Take a 2 Phase Steppermotor, its easy
Steppermotor hast most 200 Step for an complett 360 Grad turn
1 Step for 1,8 Grad
For the elektronik circuit to drive the Motor take an L297 an L298 IC .
That IC has an Input for Step an an Input for Reverse and Forward, and for half and full stepp.
When junp a Pin fron the L297 to halfstep can make 400Step on an a normal 200 Step Steppermotor, and you have an double resolution.
The Steppimpuls make whis an NE555 or other elektronik Circuit.

By

Mike

 

[polarized]

Thanks

Thanks

 

[Stark]

another solution

it depends on the size of roll you can use dc brushless motor or an asynchronous motor with a driver, bye Stark.

 

[polarized]

I have to use two motors because I should be able to reverse the process in the other direction. But, then I have a problem that they have to rotate on different speeds, because of the radious of the axel which is constantly changing. The speed of the paper is a constant to fulfill the criteria that the paper tension is a constant. I can leave one of the engines without power, but will I then notice that the tension of paper which has to be evenly distributed will not behave in this way? Anyone has an answer to this problem? Maybe, usage of some mechanical elements would solve the problem?

 

[mdamdam]

Yes ,
certainly, mechanical solution is necessary, a purely elctronic solution will be very difficult ton install and the parper will be broken.
See the old tape recorder, the tape goes on a spring loaded 3rd axis. This piece have 2 funcion: first it will compensate short time difference of you 2 axis speed and secon: the position of the axis is measured ( optical or mecanical solution ) and control the speed of the "slave" axis.
Stepper motor are a good solution beacause you can easyly control the output stage of the slave motor.
In my opinion, Allegro ICs are very good. For example the A3977 is excellent and can control bipolar motor in u-step way offering a smooth operation.

 

[Gavran]

Iz is possible to make the machine without any mechanic. Use two frequency inverters which support DC link coupling and have current limit option. Use two squirell cage motors. One will act as a brake, braking power will be determined with a current allowed to flow through the motor. You have to control only the speed of winding motor. The motors and inverters must be equal, so you can reverse the functions any time.

 

[wfond]

Info on the two drum rolls electric motor control

The solution is that you must have two servo motors. One servo for each of the drums. The servo motors, each will have an optical encoder, with the resoultion as the precision needed e.g. 100..6000 ppr. Further more, you will need to have ultrasonic distance detection sensor. The sensor will be mounted vertically to the paper sheet. This device is needed for the tension purpose. To control the tension you will need - either use a blowed air pressed vertically to the paper sheet or an extra drum pressed vertically to the sheet. Now you are going to need another servo motor - to control the air blow valve or the tension drum. However all of the servo drives are going to be controled by PLC or dedicated CPU.