Need help in controlling the speed of DC Motor ?

[Er.Electrical]

Need help in controlling the speed of DC Motor ??

Can anyone of genius mind here tell me how to control the speed of dc motor in four quadrant operation automatically without using microcontroller or PLC ??
I Want to do a mini-project where i want to setup a speed from a keyboard input so that motor will rotate in that speed ??

 

[berkeman]

Can anyone of genius mind here tell me how to control the speed of dc motor in four quadrant operation automatically without using microcontroller or PLC ??
I Want to do a mini-project where i want to setup a speed from a keyboard input so that motor will rotate in that speed ??

You would use PWM of the drive voltage via an H-bridge set of switch transistors to control the DC motor. Why don't you want to use a uC to control the PWM waveforms? You will need to do some calibration of PWM --> speed anyway, so using a uC will let you put that table in its memory...

 

[Er.Electrical]

actually its a challenge from my friend.They want me to do such things.Initally i thought to use a dc generator with the shaft of the motor and calibrate the output voltage with speed.output of this generator is converted to digital and comapre with desired speed.but don't how to implement it.So if you can guide me there,i ll feel relax

 

[jim hardy]

i wanted to see how you read a keyboard without a computer...

 

[Er.Electrical]

Yah..its impossible but forget the keyboard interface.Lets tale an volume adjusting type regulator.Just i want to fix a speed by anymeans