Solar Charging/Pulsing Circuit and Variants

[Farmhand]

Thats really cool Farmhand thanks. A mosfet controlled capacitor voltage multiplier essentially?

Have you ever thought about having a controller to detect an optimum time for the battery bank to receive a radiant "conditioning charge"? I often thought if a board was smart enough, you could designate a battery or two as a master, and then at night, if the voltages on the bank were low enough, such that they'd take a charge...and ... there was no "load" on the bank (cause it was the middle of the night...) then it could essentially pass ALL power needs to a single, known charged battery. This would handly your clocks and timers and stuff in the off grid home that you did not want to "completely power down" ... then that master battery would deplete itself "pulsing the bank" cleaning up the bank, and charging it at a time when it was sort of needed anyway (after a couple or few days of no sun).

That is a very good idea one of the best i've heard, but I think it's a job for a micro, not sure.

Do you mean to spike the batteries ? You could because they aren't being used. But I think it's best to isolate individual batteries to desulfate them.

A battery bank can be equalised as a bank though I think, by raising the voltage a bit more than usual, like to say 15.3 volts for a few hours, for a boiling clean. It is recommended. I've read it.

I really like your idea, there are a lot of interesting and usefull things can still be done with solar.

I have a video i'll upload later of my exsisting setup with 75 000uf with 1 to 3 amps fluctuating from the panels to the caps while at the same time it is pulsing 2 to 5+ amps from the caps to the battery. Looks a bit like extra energy from free energy, but it's probably not Impossible to tell really anyway.

Cheers.

[FRC]

Farmhand

Could you give a value of the mosfet to use. I do not really understand these that much yet, I just have lots of them. They have IRF360 or some such numbers on them. Could you suggest the right one for the circuit.

FRC

[sucahyo]

Thanks Farmhand, I guess the panel do prefer the load to had lower impedance. ALso mean that it charge load with low voltage faster than high voltage.


I never know the output drop when the solar panel heated up. It do work by light? So it is true that solar get higher efficiency if you use color filter? because the filter will absorb the heat from filtered color?



Interesting circuit and idea .

[kcarring]

Do you mean to spike the batteries ? You could because they aren't being used. But I think it's best to isolate individual batteries to desulfate them.

I really like your idea, there are a lot of interesting and usefull things can still be done with solar.

I have a video i'll upload later of my exsisting setup with 75 000uf with 1 to 3 amps fluctuating from the panels to the caps while at the same time it is pulsing 2 to 5+ amps from the caps to the battery. Looks a bit like extra energy from free energy, but it's probably not Impossible to tell really anyway.

Cheers.

Good point on the isolation thing, I hadn't thought about that aspect.

i recently moved to 2 banks, and heres why: When you have a battery bank on solar that is constantly in use and being charged simultaneously... not good, that is, unless you have Edison batteries.

LA batteries do not like partial discharges, partial charges, etc.. over and over... no rest...

So, I moved to two banks with switching. One bannk gets charged and the other gets used. Kind of expensive but... all in all -- my specific gravity tests are showing up much better using this method.

[Farmhand]

AN IRL540N would be ideal i'll get some of those myself. Notice in the datasheet it says Gate threshhold 1 -2 volts , where a regular mosfet is 2 - 4 volts, but thats just the threshold, it actually take 10 volts to switch a regular mosfet "all the way on" whereas it only takes 5 volts to turn a "logic level" Mosfet "all the way on". If you were to hit the gate of a regular mosfet with only 5 volts it may just turn on a bit. But to get the lowest on resistance a mosfet should turn all the way on. Thats why a logic level can work here because there is less than 8 volts to work with.

IRL540N datasheet.
IRL540N - IRL540 MOSFET N Channel Transistor Datasheet

Another- IRL3803 datasheet, these look even better they claim a 1 volt flat Gate Threshold. I already have two of these but they are more exspensive.
IRL3803 - IRL3803 30V MOSFET N Channel Transistor Datasheet

Those values are not tested for that drawing FRC, I would have prefered to test that arrangement before posting it but I wanted to explain what I meant, It might not even work. But you're welcome to try of course.


Cheers

[FRC]

Thanks Farmhand

I will probably try it with what I have on hand. Would buy the right parts when I know it will work for sure.

FRC

[Farmhand]

Thanks Farmhand, I guess the panel do prefer the load to had lower impedance. ALso mean that it charge load with low voltage faster than high voltage.


I never know the output drop when the solar panel heated up. It do work by light? So it is true that solar get higher efficiency if you use color filter? because the filter will absorb the heat from filtered color?



Interesting circuit and idea .

It's difficult to know what is the right thing to do, the capacitors charge very quickly for the first few volts but as the voltage of the caps gets closer to the open circuit voltage of the panels it seems to slow down, current is reduced in all ways i tried but to differing degree's.

I measured 11Ma initial currrent to the paralelled caps 10Ma to the series connected caps. Not much difference but the paralelled caps got to a higher voltage aswell, the more caps in paralell the less resistance or impedance allows the panels to achieve a higher voltage in low light. How I measured it in low light the difference was only .2 of a volt or something but with more panels and caps in low light and good light the difference will be there still.

As the panel gets hotter its internal resistance gets higher and availiable current gets less. I've measured my panels at over 70 degree's celcius, the ouput and the open circuit voltage go's down when they get that hot.

I'm starting to think there is no real need to switch the caps from paralell to series anyway. With enough capacitance I should be able to dump enough joules from 5 or 6 volts above the battery to cause good charging.

Cheers

[kcarring]

As the panel gets hotter its internal resistance gets higher and availiable current gets less. I've measured my panels at over 70 degree's celcius, the ouput and the open circuit voltage go's down when they get that hot.

They sure do get hot. I've always scratch my head trying to figure out if a person could combine a solar pv panel with a solar thermal panel and somehow take that heat away, and use it... The quick answer is yeah, sure why not... but.. your "collector" would be on the back, it'd have to be... and that's not the ideal position if the job is to collect heat - perhaps as cold water was pumped UP to the solar heat collector, it'd pass through arrays in behind the pv panels, cooling them...

[Farmhand]

FRC i'll try my darndest to get that mosfet dump setup together tonight on a solderless board so I can try it tommorow.

Kcarring, I thought of that too and wondered that the part of the panel under the junction/connector box wouldn't be cooled by the water as much and could cause problems for the panel because of the temp difference, but maybe it wouldn't matter, some can be removed to give access to more of that area too. Seems a feasable idea though and the pipes to and from would get hot from the tin roof aswell (might want the one's going to to get heated as little as possible), maybe the outlet could be coiled around the perimeter of the panels to diffuse and collect the radiated heat from the roof also. There could even be a way to make that heat pump the water through the system and store it under a bit of pressure maybe, somehow.

[FRC]

Farmhand

Have you checked the Bedini Ferris Wheel thread ?

G'Day Gene
I however was able to make adrawing of what I made so it should be easier to compare instead of the photo.
it is here
KOGSS1GT-1.jpg picture by Kogs1 - Photobucket
kindest regards Kogs

Read the last few posts.
I think we could use this same circuit. What do you think ?

FRC

[FRC]

Thanks Farmhand

FRC i'll try my darndest to get that mosfet dump setup together tonight on a solderless board so I can try it tommorow.

Great, would be much simpler than the one I just posted from BFW thread.

FRC

[Farmhand]

I can only half understand what the drawing of kogs does, looks alright though.

I'll post a new drawing in few minutes, i'll edit it here in this post.

Here it is, The 6A10 diode has been moved to between the panel and the capacitors. And I changed some things around to how I will try it.

I'll use 5.6 volt zener a 1N5408 diode and an IRL3705N is the mosfets I have.

I'll use a 5k pot a 0.01uf cap is all have I think, maybe I can find a 0.1 one if I look hard enough and a 100 ohm fixed resistor between the zener and fet gate.

It might work, i'll find out.

Cheers

[FRC]

Koggs circuit

Its a charging circuit. But it involves charging to caps then dumping to battery.
Part of what we want.

FRC

[Farmhand]

Umm I can't fit a 1N5408 into my solderless board without damaging it so I will use a 1n4007 instead 0.56 volts drop across mine. I found some 5.1 volt zeners so i'll try one of those too and some other values also, and if it works i'll try it with a normal mosfet just to see what happens, for sure. I've found a range of little caps aswell. My intuition tells me I should be able to at least make the mosfet switch on. Everything after that is a bonus.

Yes I see about that drawing you linked, I want to try the LED on the gate of the SCR thing I might even solder one into my board on the one I use for a tryout.

Cheers

[kcarring]

Farmhand when you use a zener diode as a voltage limiter, what, generally speaking, happens to the current. Do you always have to add a resistor in series with the diode? Thanks