Solar Power Feedback

...and LED lights are up to 4 times more efficient than Fluoro's.

I ,Priscillian, am just pointing out some things in the article that are confusing and stating why they are.

Sorry, what article do you mean

http://www.exploroz.com/Vehicle/Electrics/Solar.aspx

Now we know what you mean.

There are a couple of people on this site that will answer your question.

Rockape - I don't think there was a question - Just a complaint .

Rgds

Steve

No, I'm not complaining about anything. I was just making an attempt to give more accuracy to the article. No offence intended.

Of course you are correct, I was assuming there would be a load attached.
If there were no load only the voltage would vary with sunlight. If there was a short circuit only the current would vary. In between these limits they both vary according to the IV curve of the particular cell or panel.

a MMTP is a PWM circuit but a PWM controller does not necessarily have an MMTP function (they all should because it adds not a lot of cost or complexity) . I was talking about a simpler non tracking regulator/charger using a buck-boost switcher circuit.
It is unfortunate that the unit amp-hour is used instead of the basic unit of charge- the coulomb. Similarly the unit Watt-hour is used for energy instead of Joule. This is an historical thing I think.

"a MMTP is a PWM circuit but a PWM controller does not necessarily have an MMTP function"

If you mean MPPT (maximum power point tracker) then you will find most MPPT controllers are not PWM as such. They are programmable DC-DC Converters with microprocessor control.

PWM controller with MPPT. I don't think so unless you put the old analogue MPPT controllers in that category.

Don't know about a buck-boost controller. Terminology doesn't fit solar controllers.

On the market there are three broad classifications of solar regulators.
1 A hysteresis switch. Switch on at X volts, switch off at x+y volts. repeat.

2 A PWM controller, usually three or more stage. Stage one, switch on until battery reaches programmed voltage 1. Stage 2, PWM function to hold voltage at programmed voltage 2. Stage 3 PWM function to hold voltage at programmed voltage 3.

3 A MPPT controller. Stop DC-DC converter, apply various load conditions to ascertain maximum power point of panel under current conditions of light, heat, etc........................
Program DC-DC converter to load solar panel at that point and output appropriate voltage/current to battery for the current state of the charging regime and start converter. Repeat procedure periodically to test for change in light conditions etc....

"It is unfortunate that the unit amp-hour is used instead of the basic unit of charge- the coulomb. "

I agree. It would avoid a lot of confusion amongst those unfamiliar with the terminology. But I don't know if I could carry a 360000 Coulomb battery. A 100 Ah one is heavy enough.

(For anyone unfamiliar - 1 Ah = 3600 coulombs)

Yep I've got my Ms, Ps and Ts all mixed up there. Brain shutting down.