i have 24VDC 13A motor. iw ant to change its rpm (~2900rpm) smoothly from lower to maximum. need some kind of controller. can i build it at home?. help advance thankx

 

You can... however , PWM Motor Controllers are fairly cheap (60 - 100$) and have a lot of features that would take a long time to build at home.

If you wanna build it at home though, a simple power H Bridge and a PWM generator (microcontroller of some kind is the most popular) should do the trick.

Lots of application notes at microchip.com

 

A simple PWM controller will allow control of the motor speed; if reversing the motor is not required, an H-bridge is not needed.

[eta]

See the attached. Note that D2 (across the motor) needs to be rated for the motors' current.

 

ooops difficult to build. john hopper said that these are cheap and having many features. will anyone of u suggest some model of pwm that are cheap can handle maximum current and voltage. thnkx
i want some cheap and reliable kinda thing

 

Gee, my schematic is difficult? 15 parts isn't bad for as much functionality as you'll get.

You could replace the LM317 with a 7812. That would get rid of R1, R2, C2.

You don't absolutely have to have C5. It does make the circuit more stable though.

R5 could be eliminated, but it's a "safety valve" in case the 555 timer breaks, or you remove it from the circuit.

 

ok will try to build that one. but as i said before, iwant u to suggest some ready-made model that can handle that amount of current and easily available in the market. if that are cheap then i will prefer to buy