>A couple of things. Building pure sine inverters can be tricky, it's not the
sine wave generation that's the problem, you can do >that very well with a
chip. It's getting that sine wave to drive, at high power, inductive loads
at high efficiency.
I'm sure the >Alltrax is a wonderful controller and for those without the
ends and the ability to design those circuits it's a great way to go. >With
that said, I don't expect their giving out the circuit any time soon,
they've encased it in epoxy. Manufacturers do this often >to protect their
design. Think about it, the circuits from the ETs are 40 years old and
working without being encased, most car
>computers aren't encased either. Encasing holds in heat too. I've built lots of circuits that work in harsh environments without >encasing them in epoxy. In fact I'm working on an alternator circuit for my microhydro that won't be encased. Sure I'll make a case >(IP65) for it that will cost more than if I epoxy it but I have the added advantage of being able to 'tweak' the circuit at a later >date. I mentioned the epoxy to point out one difference between the Curtis and the Alltrax. The original Alltrax was designed as a more durable replacement for the Curtis which is not encased on epoxy. It seems to have passed the test in that regard. I was not saying that you should do it. And the Curtis 1204 is a PWM controller. I can only assume that the Alltrax is as well. |