Solar Charging/Pulsing Circuit and Variants

[FRC]

Agree

I agree with you the simpler the better. So with the Mosfet could you have some kind of cap at the end that would reach 5 volts and then switch the caps for the dump. Or some differential when the cap bank reached full potential, the
5 volts would go to the Mosfet to switch it. Actually, if it would only trigger at the full potential. I guess there would have to be some intermediary circuit in between the caps and the mosfet. Does this make any sense ?

FRC

[Farmhand]

OK I see, that method with the LED's i'll try tonight, It might work by burning off the power to the gate maybe worth a try. If I get time that is, i'm working on the bearings in my bike wheel fo my SSG, this quick release wheel doesn't use a ball race it use's a heap of single bearings. Grrrr.

I did some tests but I had to do them in low light "panel upside down", because I don't have enough capacitors to be able to tell in full sun they charge too quick.
I'll let the results speak for themselves. I used 15 000uf 35 volt Caps.

Two capacitors in paralell- 1 min = 11.1 volts. 2 Mins = 15 volts. Full 15.1 volts. In one minute they stored 1.848 Joules.

One Capacitor- 1 Min = 14.52 volts. Full 14.8 volts. In one minute it stored 1.581 Joules.

Two capacitors in Series 1 Min = 14.7 volts. Full 14.7 volts. In one minute they stored 810.338 Millijoules. Connecting in series halves the capacitance.

I got the "Full" measurement by just leaving it untill it didn't go any higher.
This was done with the panel upside down so the full 20 volts was not possible. I forgot to measure the open circuit voltage.

It's very difficult to get a proper measurement because as the panel heats up the ouput drops, the sunshine is very hot here when there are no clouds.

FRC, i'll get around to a trying a mosfet sooner or later. Probably be fairly simple. Like a logic level fet (they only need 5 volts to switch fully on ) with a small cap and resistor from the cap side + to the gate and another resitor to take down the gate charge to ground or something.

I want it to be as simple to build and understand as possible. I like simple thing the simpler the better for me.

Back to the SSG wheel bearings.

Cheers

[FRC]

Thanks sucahyo

Thanks, I still am somewhat confused. Looks like Farmhand was trying to solve the same problem before. Your circuit at the bottom does make some sense to me with the zenner diode in it. I am also intrigued by the mosfet method. I have lots of mosfets from old PC power supplies if I could utilize them for the cap dumping purpose it would be nice. But I have trouble understanding those circuits also.

FRC

[sucahyo]

Sucahyo, I am using the Bedini inverted SCR circuit for dumping from my solid state SSG circuit to convert from negative to positive energy in the battery. I am interested in how this could be used with electrolytic caps of smaller value, and how the values of the components would be changed.
The SCR is a 2N6504, the cap is NAM !0j250v, diode is IN5408. Also what
was the Inquorate thread called ?

FRC

Wrong name, should be nvisser:

http://www.energeticforum.com/renewable-energy/4887-method-dump-cap-voltage-battery-2.html

I don't realize that using SCR can not shut off problem still unsolved?

Bedini solution:

After reading your post 44n on capacitor discharge, I can see why it did not work, you can not switch that way, you must look at the potential across the whole battery system. Then invert the switch in the system and it will switch. Think about what I just said, a fet will work fine if you do that.......... Two black wires, one in and one out, look at the IRF260 fet easy to figure the difference in potential between the capacitor and the battery. And look at it for DC SOA.
John B


Brent,
I'm talking about making a solid state relay for the switching.
The Fet would get around the problems with the SCR.Mathew Jones shows the circuit a few pages back, but that solid state relay is costly so we could make that with the opto and the regulator for the gate voltage and the resistor to pull the gate off. The way around his circuit for timing is a SIDAC at 40 to 60 volts to fire the opto when the capacitor reaches the correct voltage. that is the switch I'm working on. NTE makes that part NTE6415. The higher the voltage the better, then the battery will charge fast that is what we want. Capacitor dump circuits must be double in voltage or very close to it.

John K,
I would use that coil for the side coils. and wind another by putting two of the bobbins together double the impedance in Ohms 14. And make sure you put the shield on the bottom then run the Bedini/Cole circuit. The capacitor should be about 18000Uf use a SCR and a 4.7volt Zener with two 2.8 volt super bright Leds in series with the diode circuit. Machine RPM should be not more then 25 Rpm's. just giving you a tip. Good Work

John B

[FRC]

Scr

You use SCR circuit for cap dumping method like mentioned on Inquorate thread?

Sucahyo, I am using the Bedini inverted SCR circuit for dumping from my
solid state SSG circuit to convert from negative to positive energy in the battery. I am interested in how this could be used with electrolytic caps of
smaller value, and how the values of the components would be changed.
The SCR is a 2N6504, the cap is NAM !0j250v, diode is IN5408. Also what
was the Inquorate thread called ?

FRC

[sucahyo]

Here is an of the shelf timer circuit. Wish I had one myself.

I think we can not use timer because what is needed is something that detect the capacitor voltage

I'll make a report on the tests when i'm done.

Yes I see what your drawing means now. Looks good have you tried it ?

Thanks. I just draw it. I have the relay but I don't have the capacitor and panel.

I can already do that with one cap bank but I need the oscillator to trigger the SCR to turn off. It turns on ok but not off thats an SCR thing if the power keeps flowing it stays on I think.

You use SCR circuit for cap dumping method like mentioned on Inquorate thread?

[Farmhand]

Well I agree sucahyo I need to test it to be sure, I have a small panel 5
watts so I can test it with some big caps i'll do it tomorrow. Should be clear sky. I'll make a report on the tests when i'm done.

Current limiting is used to drive the relay at required voltage. Not to limit current from the solar panel.

Yes I see what your drawing means now. Looks good have you tried it ?

I agree series dumping may not be desireable anyway, now that I think about it the solar panel works at maximum power at 17.8 volts so just charging caps to 6 volts above the battery or a fixed 19 volts alternately might be best way after all. It would be a lot easier too. I can already do that with one cap bank but I need the oscillator to trigger the SCR to turn off. It turns on ok but not off thats an SCR thing if the power keeps flowing it stays on I think.

FRC I would't mind one of those myself. I have a PIC controller Dev board but I don't know how to use it yet.

Cheers

[FRC]

Thanks Farmhand and sucahyo

Here is an of the shelf timer circuit. Wish I had one myself.

Multi Mode Timer Circuit

George

[sucahyo]

Sucahyo, I didn't actually mean two caps in paralell would reach desired voltage quicker, rather that two in paralell charged to a certain voltage contain more energy than two in series and when the two in paralell are switched to series the voltage would be double the series charged one's.

But charging two in paralell should be quicker than charging two separately to the same voltage one after the other. Because of the lower resistance of the paralelled one's.

Thanks, but I still confuse....

What happen if you put a volt meter only on one capacitor and put this capacitor along the rest for parallel and series charging test. I think the test should only be done with solar panel because using battery and power supply may change results. It is a test of what kind of load is better for the solar panel. Low impedance or high impedance? Or doesn't matter?

Because we don't know if dumping in series would be better than dumping in parallel or not.

Maybe discharging in series allow longer charging to the battery, but it will also lowering the capacitor voltage. So:

discharging in parallel: short discharging time but higher left over voltage, causing faster regaining dump voltage.

discharging in series: long discharging time with lower left over voltage, causing slower regaining dump voltage.


I think this must be tried for real since battery may have different result from being charged with high voltage differential (series) than low voltage differential (parallel).

Charging battery with cap in series may have worse result. So knowing what kind of impedance the solar panel like is important.

Limiting the current kind of defeats the purpose, I want to remove any current limiting effects.

Current limiting is used to drive the relay at required voltage. Not to limit current from the solar panel.

[Farmhand]

Sucahyo, I didn't actually mean two caps in paralell would reach desired voltage quicker, rather that two in paralell charged to a certain voltage contain more energy than two in series and when the two in paralell are switched to series the voltage would be double the series charged one's.

I don't have enough time just now to study your drawing but I like the look of it. I'll watch the video now though. I can't say for sure What the benifits would be. But charging two in paralell should be quicker than charging two separately to the same voltage one after the other. Because of the lower resistance of the paralelled one's.

Limiting the current kind of defeats the purpose, I want to remove any current limiting effects. Maybe I miss understand, I think that relay array might be good I can't follow all the wires but I trust your judgement, i'll look at it better later. The current limiter definately works.

FRC, I'm not sure how I will do it yet, no idea, but it must be possible. I was just thinking on it and figured it was worth a try. Make no mistake if I could already do it I would post a drawing and a video.

I like to share even my idea's. Maybe someone can do more with my idea's than i can. I will need to make some drawings as I think. Or adapt a method for a similar thing from somewhere else.

Cheers

[sucahyo]

Thanks sucahyo for the video. What is the KVR is that a pot ?

Yes, variable resistor, potentiometer.

[FRC]

Confused

Thanks sucahyo for the video. What is the KVR is that a pot ?

@ Farmhand, I am confused as to how you switch the caps from series to parallel or vice versa ? Some weird kind of switch or something. I was also wondering how to do this. The only thing I could come up with would be. One
or more large caps parallel then smaller ones in series to match the larger ones voltage, and then tap one or more of the smaller ones for your desired voltage. These smaller taps could be further paralelled. The same could be done with a combination of batteries. And I am going to use this method for batteries to come down from a higher voltage to a lower one for a circuit I am working on.

FRC

[sucahyo]

I see. Maybe you should use power supply to test the idea if the solar output is irregular.

You mention all cap reach specified voltage faster in parallel? So if you only measure voltage of one capacitor, three in parallel reach specified voltage faster than three in series?

My idea:
We use transistor to limit current to the relay. The resistor value will determine at what voltage the relay will be activated, so this is trial or error art...
YouTube - Simple current limiter with one 3055 transistor and resistor

See if you can spot any error:


How it works:
- the resistor will control the amount of current in the transistor. The transistor will monitor charge in the rightmost capacitor. If voltage is high enough the relay will trigger until it is depleted. turning on relay usually need more voltage than to sustain on, so relay stay on a bit longer. May add cap in parallel with the relay to lengthen on time.
- during off, first capacitor bank is in parallel and receive solar charge, second capacitor bank is in series and charge the battery.
- situation reverse during on.


The circuit can be done with relay with 4 contact like FRM3-4B5, problem is, it is limited to 5A.

[Farmhand]

Hi sucahyo, I'll try to answer your questions that I can, I haven't really tried anything yet.

- how do you use the battery? Do you utilize battery while charging it or you have two array so you can charge one and utilize the other or swap them?

I think two battery banks would be the better option.

- Do you also charge battery in parallel and discharge in series or is it not possible to do?

The battery could be charged in paralell and used in series. Not sure if there would be a benifit to that or not, maybe.

- have you tried to compare capacitor charge in parallel dump in series VS charge in series dump in series?

No I haven't tried that yet, it's just an idea that I haven't acted on yet, I thought i would share.

- how do you know it is better, by timer? time of charge vs time of dump?

The switching to series is mainly to get a higher voltage than what the panels output, charging them in series will only allow the cap voltage to get to the same as the panel voltage. If the caps are charged in paralell to 17 volts then swapped to series the caps could be dumped from 34 volts to two batteries in series from a panel that can't put out 34 volts. The switching to series could also be used to charge a battery from a voltage source lower than the battery.

I'm just theorising at the moment. I want the setup to be able to handle 10 amps or more from the panels. But also to work in low light.

It's very hard to test charge times from a solar panel unless there is clear skies. The panel output fluctuates with clouds. Lowering the resistance by paralelling should make them easier to charge, theoretically especially since the stored energy in the paralell caps will be double the stored energy of series connected caps charged to the same voltage.

I think the two cap banks need to be tied together in an alternate fashion, locked 180* out of phase kind of. I don't want to use a timer. I would like to have the caps dump when a certain voltage is reached, somehow.

It is possible that a relay would be a very good option for the alternating control and decoupling. It's kind of made for it, a relay has two paths that can alternate and decouple at the same time.

Good thinking Sucahyo.

I just thought I would put this out there for a while before i start to work on it, incase sombody else can think of the details better than me.

Maybe a combination of relay and Bipolar transistors or a combination af relay and SCR's or even relays and mosfets.

I'm not overly fond of timer chips myself. But I will use them if its the easiest way.

I'm kinda fishing for idea's, but it's to benifit all, not just me.

A regular charge controller restricts the current when the battery is almost charged to prevent overcharging. I would rather it kept output at maximum and swapped to a different battery or dumped load to a fan to cool me off.

Cheers

[sucahyo]

Thanks for the explanation Farmhand .

The setup do sound complicated. Some question:
- how do you use the battery? Do you utilize battery while charging it or you have two array so you can charge one and utilize the other or swap them?
- Do you also charge battery in parallel and discharge in series or is it not possible to do?
- have you tried to compare capacitor charge in parallel dump in series VS charge in series dump in series?
- how do you know it is better, by timer? time of charge vs time of dump?



Sounds like your solution better be done with relay. But not sure if potentiometer in series with the relay can be used. You need two. One for each cap. then this relay control a bunch of other relay.... I can try to make some design for this if you want to use relay.