MC33030 chip help

[mlaws1172]

I am looking at the MC33030 chip as a way of driving a damper actuator. Everything looks good except I need to 4 amps at 24vdc. Figure 30 of the pdf shows a circuit, would this work and if it will, what components?
Thanks for any help, I attached the pdf
mike

[Al_The_Man]

The IC is obviously intended for what you want to do, fig 30 shows how to increase the drive capability, you will need a couple of complementary pairs for the external H bridge,
I have used MJE2901 & MJE2801 in the past, you need to look up a modern equivalent.
Al.

[mlaws1172]

thanks al
can you tell me how they are figuring the resistors. Sorry for the stupid questions?
mike

[Al_The_Man]

I assume you mean RE? You would need to know the forward volt drop of the diodes and the B-E voltage when the tr is on.
I would say in your case a ball park would make RE around .17 ohms. This is to retain the current limit feature for a stalled motor. Initially put a low fuse in your 24v for trial purposes.
Al.