Using TIP142 insteed of TIP120 to run stepper motor.

[musicworld1]

I am going to use TIP142 in steed of TIP120 in the following picture and want to operate the stepper at 24V. so which resistor I should use? Or what is the rule of thumb to use resistor.

[irving2008]

I already gave you the equations in the attachments on the previous thread. The TIP142 wont change what resistor you use and you will still have the same heatsink problems as the TIP120. GO back and re-read that thread, then post your own calculations and I'll validate them for you....