Difference in "PWM" controllers

garlic

I had read somewhere yesterday someone stating that the Xantrex
C series controllers were not "true" PWM controllers.I was wondering
then If someone could please explain the difference in technology (if any)
between say a C35 and a Prostar 30 as far as how they apply current?
Are there any substantial advantages or just a different way to get to
the same destination?Not that this has any major bearing on what my
system plans are.I'm just curious as to how they might be different.

Thanks,

garlic.

niel

Re: Difference in "PWM" controllers

they are pwm controllers. i don't know of any basic differences. if you think of what was really said about it and where please tell us as i'd certainly be curious who said what.

garlic

Re: Difference in "PWM" controllers

I hope I wasn't taking it out of context,though I don't believe I was:

http://www.solar-guppy.com/forum/general-charge-controller-suitable-for-jacobs-wind-turbine-t207.html

An FYI

the Xantrex C40/C60 is not a true pwm contoller , it lacks the inductor part for that. It is really an On/OFF controller.

I just wanted to make sure I understood the technology correctly

Thanks,

Garlic

mike95490

Re: Difference in "PWM" controllers

I think there was a typo in that message.

A simple FET can perform PWM control (Pulse width modulation) and needs no inductor.

A MPPT controller needs inductors, so it can perform the voltage downconversion.

The C-xx series is all PWM controlers

BB.

Re: Difference in "PWM" controllers

That was about 9 years ago... Not answering for Solar Guppy, but today, as Mike says, we call PWM as "on/off" controllers.

And controllers that use inductors are MPPT (Maximum Power Point Tracking) which, usually inside have a switch mode power supply that is Buck type down converter. Which has the inductors to allow the MPPT/Buck Mode type charge controllers to efficiently take high voltage / low current and down convert to lower voltage / higher current for the battery bank.

Buck Converter

Without the inverters, the CXX family is just a PWM (pulse width modulation) On/Off switch...

Buck converters also use PWM internally to control their operation--Probably the root of the confusion...

A MPPT type charge controller costs about 3-5x more than a PWM / On-Off controller. And typically MPPT are used with larger systems (say more than 400-600+ watts)

PWM's tend to be used for smaller systems (~200 watts and under).

The MPPT is a more flexible controller that can allow you to place the solar panels much farther away from controller/battery shed because you can use a higher voltage solar panel array...

They are nice--but not cheap.

-Bill

garlic

Re: Difference in "PWM" controllers

Thank you folks for ironing out this wrinkle.

I knew the difference between mppt and pwm.I thought maybe
I had missed some disparity between the Cxx CC's and other pwm types and
that motivated me to ask what they might be.

Thank you again,

Garlic