Re: [CAD_CAM_EDM_DRO] Re: stepper driver help

I wrote:

> The L298 can do 2-3 A (depending on duty cycle) *or* 46 V, but not at the
> same time. It's limited to 25 Watts, ie 3 A @ 8.3 V or 0.5 A at 46 V.
> And that's *total* power dissipation, the L298 has two internal H-bridges,
> so if you use both you're limited to 12.5 Watts per H-bridge.

"Paul Kelly" <tech@...> wrote:

> [Paul Kelly] Ahhh,, no. Those equations only come into play when it's
> switching.
> The dissipation is Volts (across the device) * Amps. As each leg of the
> bridges turns on and off (which they do a lot for current control) there is
> a time when the voltage and current are both high, heat is generated then.
> When the 298 is conducting, you might see 1 or 2 volts across it.
> With a small heatsink I run 298's at 2A and 38V in my lathe all day.

Wow, the 25 W is dissipation *in the L298*, of course! <smacks forehead>
I'm so glad I was wrong!

Thanks for setting me straight Paul! :-)


--
Sebastian Kuzminsky