Help! DIY 4 amp L297/6203 driver

[Ross77]

Thanks for the input, most appreciated.

The mono stable and astable idea sounds good but beyond my capabilites so I will have to wait for your input
I found a circuit that uses a 555 to pull vref down after 10s, its from a unipolar design that uses an L297 so i presumed it would be ok.

I'm not sure if I fully understand the timing delay, I presumed that the control circuit would activate the lower vref so soon as the clock stopped? but looking at this I think it only works after 10s of inactivity. so in most cases the current will be full power?

[irving2008]

Thanks for the input, most appreciated.

The mono stable and astable idea sounds good but beyond my capabilites so I will have to wait for your input
I found a circuit that uses a 555 to pull vref down after 10s, its from a unipolar design that uses an L297 so i presumed it would be ok.

I'm not sure if I fully understand the timing delay, I presumed that the control circuit would activate the lower vref so soon as the clock stopped? but looking at this I think it only works after 10s of inactivity. so in most cases the current will be full power?

The delay could be made adjustable, but that circuit would do the trick. It needs a lot more parts than the PIC, that is the attraction of using the PIC...

I dont think a PIC program would be hard to create, using a 16F84 or equivalent...they are only a few pence now and programming them isn't hard (I can do it, so can at least 2 or 3 others)

[Ross77]

Thanks Irving, Is that an offer to create the code? :clap:

I have a programmer that I bought many years ago, but never built, that supports that chip. So the final decision is wether to include the short cuircuit protection as it dose complicate the board a tad. Is it really worth the hassel? I first thought it was also an internal overload but after finding the application sheet it is only for output short circuit, maybe I'll just have to be carefull with the motor wiring :whistling:

[irving2008]

Thanks Irving, Is that an offer to create the code? :clap:

I have a programmer that I bought many years ago, but never built, that supports that chip. So the final decision is wether to include the short cuircuit protection as it dose complicate the board a tad. Is it really worth the hassel? I first thought it was also an internal overload but after finding the application sheet it is only for output short circuit, maybe I'll just have to be carefull with the motor wiring :whistling:

I'll have a think on it...

Which bit of short circuit prtection?