DC motor control progressive start and stop

[reinaldo]

hey Everybody!...
I`m stck with the Control of a DC Motor...I need To Control a DC motor in this way, it Must Start real slowly, and then progressively but slowly should continue to reach its maximun velocity, it could take up to 1 min to reach it; then remain for a set time stable at its final velocity and after the time pass then start to slow down in the same opposite slowly way as the start...how would i do that??

 

[berkeman]

hey Everybody!...
I`m stck with the Control of a DC Motor...I need To Control a DC motor in this way, it Must Start real slowly, and then progressively but slowly should continue to reach its maximun velocity, it could take up to 1 min to reach it; then remain for a set time stable at its final velocity and after the time pass then start to slow down in the same opposite slowly way as the start...how would i do that??

You need to use pulse-width modulation (PWM) on the DC to the motor. You vary the pulse width from narrow to wide to full-on to go from slow to faster to full speed.

See PWM for Power Delivery here: http://en.wikipedia.org/wiki/Pulse-width_modulation#Power_delivery