Favorite PWM Control Chip?

jcb344

I was wondering if anybody could recommend a cheap PWM controller chip that has several outputs. I have looked around on the web but could only come up with pricy solutions. Thanks.

-Jacob

julienj

Have you ever done anything with the SX? Bean has posted code for a 16 channel PWM control that interfaces with the Basic Stamp.

http://forums.parallax.com/showthread.php?p=536244

Of course that would mean the investment in an SX-Key or SX-Blitz if you have not done so, but the one time investment is well worth the couple of bucks.

Hope that might help, though I'm not sure it was the answer you were looking for.

Steve Joblin

Not quite sure what your definition of "pricy" is, but have you seen http://www.awce.com/pak5.htm

Pololu also has a nice selection of motor driver chips that use PWM... http://www.pololu.com/catalog/category/11


Post Edited (Steve Joblin) : 4/28/2008 7:19:29 PM GMT

tedbeau

Here is an inexpensive way to create a PWM circuit for two DC motors using a 755410 Dual H bridge chip and a 556 timer.




The two chips each cost less than $2.00 US, I think. I have built and tested this circuit using a fixed resister inplace of the variable resistor (pot) at R4. By changing resistors R1, R2 and R3, R4 its possible to change the duty cycle of the output of the 754410 from 93% to 52%.

There is information here:
http://www.kpsec.freeuk.com/555timer.htm· (see 555/556 Astable·section)
on the calculations for the Resistors to achieve desired duty cycle.

Each side of the 556 pulses the corresponding output pin at the desired duty cycle. The outpin pin is tied to the enable pin of the 755410. When the enable pin is high, the motor is powered. Pulsing the enable creates the PWM.

For information on using the 755410 see this page:

http://www.hobbyengineering.com/appHBridge1A.html