3 Battery Generating System

[LutherG]

Nice run!

Don't worry, we all learn from mistakes. I doubt you could use same meter and believe you have discovered something important. I found converter on eBay and it fits your description; fins, 17lb etc. but they quote shipping to Canada about $100 but for US only $25
After two days of failures I discovered wrong connection in my setup. I couldn't believe I could done it Now, when I can hear transformer singing I realized that this sound was missing until today. I simply mislabeled start and end of one through winding.

Just finished second run, this time 1.5hr and converter with 13W bulb as a load. GB and P1 were sitting at 12.41V - 12.40V and 12.37V - 12.35V.
A2 sits at 11.7V despite having few nails inside.
After 30min GB and P1 are 12.60V and 12.56V.
This time I was running at 2.55 kHz.
It looks good to me. I was going to try heavier load but my batteries aren't deep cycle and I don't want to drag them down too low.
Is anybody else beside Matt working on this variant?

Cheers
Vtech

Nice run! I've got parts on order to build Matt's latest schematic.

Regards,

Luther

[blackchisel97]

Nice run! I've got parts on order to build Matt's latest schematic.

Regards,

Luther

Hi Luther,
I'm driving FET from function generator which gives me control over freq. duty cycle, offset etc. I'll get proper driver done later. I was just to anxious to test it. I set it for third run tonight. I'll hold for 2hr and record results.

Cheers
Vtech

[Matthew Jones]

I am going to set up another one this week. I got my big 3kva trafo back. It'll be interesting to see what it and a couple 1400 cca batts do.

I gotta couple of more ideas to try out with the caps and stuff.

Matt

[blackchisel97]

I am going to set up another one this week. I got my big 3kva trafo back. It'll be interesting to see what it and a couple 1400 cca batts do.

I gotta couple of more ideas to try out with the caps and stuff.

Matt

I'll search for couple of large EI as well. I want one for your TS replication.
I tried substituting A2 with cap but I think it should have fairly large capacity. I only have 10,000uF available atm.

I took a shot of secondary AC side and below scope across GB. Those spikes are beyond the screen but they would be poorly visible at higher V setting.
Just finished third run. After 30min rest GB and P1 recovered to 12.56V and 12.50V, so in total during 4 hrs runs with 20W load I lost approx. 0.07V
[IMG][/IMG]
[IMG][/IMG]

Cheers
Vtech

[bitbox]

Some precisions required

Hello,

About a month ago me and a friend decided to try and set up this 3BGS, but unfortunately it seems we haven't been lucky enough to pick one right "good bad battery" not even dreaming of getting 3 of them. It has become pretty hard to find old batteries around my place since they do so much to have everyone recycle them !

When I read Matthew Jones' post describing a possible system using no motor and replacing A1/2/3 with capacitors I regained serious hope that we "might" finally join the party...

I downloaded the schematics and went literally image by image through Matt's video covering his first setup (still with a battery as A3) to understand it as correctly as I could. I must admit I have no experience in electricity whatsoever and though reading a schematic doesn't scare me, it is not always easy for me to understand what component to use and where.

That is why I redrew Matt's schematic (the "N" one) in a more realistic view of the components. I've attached this drawing to the post (as a pdf file for readability). In the process I also tried to identify suitable components that might fit the requirements. So here comes my humble help request: could someone of the more experienced people around this thread please take a little bit of their precious time and review my attempt and probably correct it ?

Components references that I (supposedly) identified are noted on the drawing, those in orange are the ones I have doubts or questions about (many of them ). If of any use to the potential reviewer of my drawing, here is a list of digikey's website references of the selected components:

MOSFET and gate driver
IXTN170P10P IXYS | IXTN170P10P-ND | DigiKey
FOD3180 Fairchild Optoelectronics Group | FOD3180-ND | DigiKey
Transformer

http://search.digikey.com/scripts/DkSearch/dksus.dll?keywords=VPS230-110

Capacitors

http://search.digikey.com/scripts/DkSearch/dksus.dll?keywords=ECET2AP123FA

http://search.digikey.com/scripts/DkSearch/dksus.dll?keywords=CGS422U075R4C

DC converter

http://search.digikey.com/scripts/DkSearch/dksus.dll?keywords=VFSD2-S24-S12

I'll now shoot a few questions I have and that are hopefully not so stupid that no one would even care to answer them (sorry if they are).

From what I saw on Matt's video, and from blackchisel97's earlier posts, I think I understand the MOSFET gate driver must be triggered by some sort of pulsating signal that will act as the "balance" to the load that is placed at the A2 end of the circuit, am I right ?
blackchisel97 reports running at 2.55 kHz with converter and a 13W bulb saying he's using a "function generator which gives him control over freq. duty cycle, offset etc...". Could you please tell us more about this function generator. I saw that Matt is using a "Parallax Propeller" and digging this indicated that it is a programmable microcontroller .
Any help pointing in the direction of suitable material would be appreciated, also I can quite easily understand that a "function generator" could generate a pulse at a given frequency, but what is the duty cycle and how/why control it ? Same for offset, any additional information in that field is welcome.

Back to the components, in Matt's video it appears that the setup he had at the time he shot it wasn't "complete" compared to the posted schematics. I noticed two main differences:
1- I couldn't detect the diodes (and their wires) that are linking A1 and A3 to P1+ and GB(P2)- , what model should those be ? I recall reading earlier that they have to be "super fast diodes", is that right ? (part reference welcome)
2- I couldn't either detect the capacitors that are in the schematics right at the output of the rectifier. A few questions here:

• could someone give a part reference for the D2 rectifier ?
• could someone enlighten me about those capacitors function (C1/C2 in my drawing) ?
• I assumed from previous posts that 4200uF/65V could fit for them, is it correct ?

And here comes my last question at the moment: the voltage converter I picked is mostly shooting in the dark... Could someone explain me what are the requirements for this component (in the current circuitry I mean) ? Once again part reference is welcome.

As a final note, remarks regarding mistakes that I might have done in my drawing are also welcome naturally

Well, hope this post isn't too long and will get a chance of bringing me the answers I still need before I go and order everything to start building it !
Oh, btw has anybody already tried the 3 capacitors as accumulator configuration ?

Thank you all for sharing this and hope to hear from some of you soon.

Thibaut

[blackchisel97]

Welcome bitbox,

FET's need to be driven in certain way to switch properly (just as bipolar transistors do). What is needed here is a pulse generator/driver which will provide square pulse (preferably with regulated duty cycle - ON/OFF time) and variable frequency.
Ideally, generator it should be galvanically separated eg. by optocoupler to prevent any spikes from destroying IC in it. There are many ways to get this done and many IC's will work, including 555.
STAMP or PIC will provide precise pulsing and can be adjusted by changing code.
I have couple IC in the mail but since I have BK function generator, I decided to use it. It provides square wave and I can adjust dc from 1-99% but I'm running at 50% here. I also have option of variable TTL/CMOS outputs.
I have a negative budget atm. and I try to work with the stuff I have available.

I'll try to answer you other questions later but Matt would be the best person to address them.

Cheers
Vtech

[Matthew Jones]

I am about to show some more stuff. A few more components so If it were me I would hold up. That way I'll be able to tell ya if all this works out or not.

Just make sure the rectifier is rated high enough to do what your doing. I cannot predict your loads and stuff.

Everything else looks OK.

Matt

[bitbox]

Thank you guys

Thank you guys for taking the time to answer me...

blackchisel97, I'll certainly have to read your answer a few times again and google a lot for it to make sense to me but I'm convinced the information it contains will lead me to a better understanding of what is required as a "fonction generator"...
I would also greatly appreciate any further answer if you find the time...

Matt, I'll definitely wait for your post before going any further !
Tanks already for taking the time to look at my drawing and reassure me that I don't have it all wrong after all

I'm so impatient to join you guys in the building !

Regards.

Thibaut

[Matthew Jones]

What I am setting is basically a pretty solid method for keeping the batteries charged, while running a load.

I have become convinced though that a gradual loss is going to be inevitable unless somehow an outside power source is introduced into the system.

But maybe we can end up with something like a 100 watt load running with a 10 watt or so supplement. Thats fairly significant. And I don't mean for an hour. I am personally looking at month.

I already know from some other projects I have running at the moment that you can extend the power taken from the batteries pretty far. But to achieve a stable battery charge it takes 6-8 times more (Depending on the battery health) to keep the batteries from falling while running. And it is a highly processed method for re introducing the power.

If you aren't up to speed on an IC you better start getting there.

As soon as its all stable and safe I'll get it to you guys.

Also you can pick up a Propeller from Radio shack about 35 dollars. I can tell ya from personal experience and others who have took the advice its worth every penny.

Matt

We'll end up with somthing

[blackchisel97]

Thank you guys for taking the time to answer me...

blackchisel97, I'll certainly have to read your answer a few times again and google a lot for it to make sense to me but I'm convinced the information it contains will lead me to a better understanding of what is required as a "fonction generator"...
I would also greatly appreciate any further answer if you find the time...

Matt, I'll definitely wait for your post before going any further !
Tanks already for taking the time to look at my drawing and reassure me that I don't have it all wrong after all

I'm so impatient to join you guys in the building !

Regards.

Thibaut

I didn't mean to make things complicated, sorry about that.
In this setup FET transistor acts as a simple ON - OFF switch, connecting two batteries in series for a brief moment.
In order for transistor to do that we need to trigger its base withe relatively small pulse. This pulse has to last certain time and turn off. Duty cycle means relation between ON and OFF time. 50% means they're equal. This is a square wave. In order for any transistor to switch sharp this input pulse has to have sufficient amplitude. (sometimes referred as a "hard switching").
For this setup you don't need a function generator, only square wave with adjustable frequency and duty cycle.

I hope I expressed myself clearer

Vtech

[blackchisel97]

What I am setting is basically a pretty solid method for keeping the batteries charged, while running a load.

I have become convinced though that a gradual loss is going to be inevitable unless somehow an outside power source is introduced into the system.

But maybe we can end up with something like a 100 watt load running with a 10 watt or so supplement. That's fairly significant. And I don't mean for an hour. I am personally looking at month.

Matt

We'll end up with something

10 Watt supplement for such a long run would be great. If up-scalable, say 100W for 1kW .
I'm thinking of something but I need to try it first. Maybe nothing.

Vtech

[shylo]

battery charging

Hi Matt,...you say it takes 6-8 times more to achieve a stable charge...
Does that mean 6-8 times higher than battery voltage?....72-96 volt pulse??
Or is it 6-8 times more than what were drawing off the batteries??

I currently have 6 coils on my pmg (room for 30 more)..I can charge caps to 14volts in ~3 sec , then discharge into P1.....but I don't think this will maintain charge.....but by adding more coils I will be able to dis-charge caps into primaries faster.

I can make the cap bank ,either higher in capacitance or voltage or both.( I've got a bunch of caps)

I've tried alot of different scenario's with this ,but eventually the primaries lose in the end.......just need to keep them topped up.

Just curious what your view is on pulse charging batteries, Or anybody else's for that matter.

shylo

[bitbox]

I get it

blackchisel97, thanks for the clarification, it's crystal clear this time !

Cheers.

Thibaut

[Matthew Jones]

Hi Matt,...you say it takes 6-8 times more to achieve a stable charge...
Does that mean 6-8 times higher than battery voltage?....72-96 volt pulse??
Or is it 6-8 times more than what were drawing off the batteries??

I currently have 6 coils on my pmg (room for 30 more)..I can charge caps to 14volts in ~3 sec , then discharge into P1.....but I don't think this will maintain charge.....but by adding more coils I will be able to dis-charge caps into primaries faster.

I can make the cap bank ,either higher in capacitance or voltage or both.( I've got a bunch of caps)

I've tried alot of different scenario's with this ,but eventually the primaries lose in the end.......just need to keep them topped up.

Just curious what your view is on pulse charging batteries, Or anybody else's for that matter.

shylo

6-8 times the power to hold the battery steady. The trick is you can hit with less at higher voltage 2x-3x but the battery has to be off or just turning on when you do it.

I do not know what PMG is...

Matt

[blackchisel97]

6-8 times the power to hold the battery steady. The trick is you can hit with less at higher voltage 2x-3x but the battery has to be off or just turning on when you do it.

I do not know what PMG is...

Matt

I guess, he is referring to permanent magnet generator...

Vtech