Solar Charging/Pulsing Circuit and Variants

[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

[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.

[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]

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

[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]

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

[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.

[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 .

[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

[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.

[kcarring]

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).

[Farmhand]

Here's a drawing (attached) I was in a hurry and made some mistake's, the zener and the 1n5408 should be swapped positions (the zener could be 4.7 v and a different diode could br substituted for the 1n5408). The 6A10 diode can also be substituted with a suitible one and it's 0.5 or so drop (measure it) needs to be added to the total for the drop difference.

So that would be 17.8 v. See below. If the panel put out 20 v max it would stop pulsing at 14.2 volts. Well thats the idea anyway.

Battery 12.0 v
zener 4.7 v
6A10 0.5 v
1n5408 0.6 v

It all depends on the output voltage of the panel and what voltage you want to charge your battery too.

Cheers

[Farmhand]

Drawing

Hi FRC, i'm not sure about the battery tester, I think they can work several different ways.

The mosfet switch would work very much the same as the SCR, When the switch is off the caps charge up past the battery voltage, when they reach say 6 volts above the battery the voltage difference is enough to break through the zener diode to the gate which switch's the mosfet "on" to dump the caps. The resister from mosfet gate to ground pulls the gate charge down to turn the mosfet "off" then it repeats. The rest is just details. but thats just one dumper which may be all you want. I'll need two of them to alternate, controlled by a relay or something like sucahyo's drawing, maybe a combination. But I do need to work out a viable single dumper first, so thats whats i'll try to get done. My SSG bearings are fixed. Tonight i'll try to whip up a test circuit with a mosfet and another with the SCR and LED's.

I'll see if I can do a quick sketch to help me explain what I mean, i'm not a very good explainer. I'll post it as soon as I can. Very busy now the rain is gone, I lost two months work time because of constant heavy rain.

I'm just having a break from work at the moment. More to do yet. I've got a goat with a abscess to deal with, it's not very yummy to look at, the poor thing.

Cheers

[FRC]

Battery charger

A battery charger that has lights that go from red to green when batteries are
fully charged could be used. Hook up to the caps instead, when the light turns
green it would trip a switch to dump the caps then repeat. Small 12v battery
booster packs also have this function. I have some old ones that just might work. They have lost their usefulness, but when hooked up to caps the light
function could be exploited for cap dumping. Will have to try it. What do you
think Farmhand ?

FRC

[FRC]

Computer

I know I could do timing and switching using a Computer. I have programmed my own timer programs before. Also a crude Tesla switch could be done this way. But the computer is going to draw power.

FRC