Water Sparkplug

[xpskid]

Hi all,

video at:

YouTube - VexUs Hybrid CDI high speed bench test

Greg,

That was way too cool !!!! Great job my man !!!


Timm

[insane4evr]

insane4evr,
.......So this is telling me that the high voltage that the circuit is adding to the vehicle ground is feeding back into the inverter output and causing it to trip?

If this is true, then I wonder how it is effecting other systems on the vehicle i.e. the charging system or even the computer.
....LappperL

I think the inverter electronics section that make the modified sine waveform has a 'back-circuit to its 12 VDC (13.8VDC?) section. It probably will not affect the car electronics. Of course it is not working for you.

Some inverters have extra isolated winding in its internal transformer and this is used to power the chip(s) that ultimately generate the stepped AC waveform. It seems that yours don't have this extra winding and the chip(s) are powered (down regulated probably) from the same battery input. Hence, the back-circuit and its bad effect when the AC output finds a way back to its battery input - and back to its waveformer chip(s). Whew.

[gmeast]

rectifier

Is this the one? $2.57 each
RECTIFIER BRIDGE 600V 35A MB-35 - MB356


Comparable seems NTE5342:
http://www.nteinc.com/specs/5300to53...nte5340_44.pdf

Hi cowboyrx,

Mine looks like the one in this data sheet:

http://www.diodes.com/products/inact...ta/ds21303.pdf

Peace,

Greg

[gmeast]

hi speed

Here is a video of Greg's VexUs circuit firing plasma via my V-8 HEI distributor. The max speed on the drill I used spun the distributor at 2,300 rpm. No misfires, even if you see that the camera may not have captured them all. A VERY crisp sound from the plasma at 2,300 rpm, I was completely ASTOUNDED!! Here you go, more to come.....................

HEI V-8 VexUs plasma---2,300 rpm

Enjoy, I sure did while I was filming it!

Hi jstadwater,

Great video. Did ya see mine?. Thanks for using my circuit, and the EMF data from you laptop is very good to know. I am working on component ratings so this circuit can be built and run indefinitely at automotive specs with acceptable heat rejection at the CDI Cap and Diodes.

Thanks for sharing. Peace,

Greg

[vzon17]

Hi Greg,

Everything you said is correct. My idea is not to resonate the circuit but to 'soften' the rate of discharge current on the big cap. With the inductor, the value of R1 if it has to be added can probably be reduced to shorten the rate of C1 re-charge. Of course this is just theory.

I have re-drawn your schematic with the inductor and also just to help me understand it better. I hope you don't mind my posting it.

----------------------------

Actuallly I posted a circuit a few weeks ago about this very thing. You have the big cap being constantly loaded by the FWBR and the smaller cap is discharged by the spark plug. If you put a resistor between the big and the small cap then the big cap won't be drained all the way when the little cap gets fired.

Doing it this way allows the big cap to stay fuller and keep up a steady supply to fill the little ones instantly.
It is based on the old Tube amplifier power supplies that had capacitor resistor networks to filter the DC to make it real smooth. Same principle. You can even have three caps in paralell with resistors in between each one. the resistance value I am not sure of but they are not real high. you don't want them slowing down the charge rate going to the small cap. make the resistor a low enough value to keep the small cap fully charged yet at the same time not depleating the larger one.

[gmeast]

resistor

Hey everyone,

After I shot the vid spinning the V-8 distributor at 2,300 rpm, I noticed the capacitor was too hot to hold. The single HV diodes were only barely warm enough to feel any heat at all. The larger banks of diodes had no detectable heat at all. I should probably use 2 or 3 HV diodes parallel each plug for longer term use, probably the ultra-fast recovery ones Greg uses, that fixes the diodes. Would I be correct to assume that by using a 100 watt light bulb instead of a resistor that "fits the bill" maybe that's why my cap gets hot in a short time? I forgot to check the storage cap at the FWB to see if it also was hot. I am still only charging at 110V at this time. After seeing that spark at 2,300 rpm, and then seeing Greg's spark at 5,000 rpm I'm almost afraid to boost the circuit to the 300V I was going to try out! Would it help my cap heat if I used a lower watt light bulb, I wonder? Any suggestions are welcome, as always, thanks everyone...........................Mike

P.S. That is some serious FLAME-AGE you got firing there Greg!!!

Hi jstadwater,

You should probably be using about 75 to 80 ohms and rated at at least 100 Watts. You should be using a power resistor with a heat sink. The capacitor should probably be no more than 22uf and capable of fast cycling like a flash capacitor. If you can't find that then you can use aluminum electrolyte caps grouped together. I have used 4 22uf caps grouped as two sets of two 22uf caps in series and then connect these two set in parallel. If you are using 400 VDC caps this series-parallel grouping will give you 22uf good to 800VDC. This will help the heat issue.

We are switching real power levels here, so the components should be 'power-rated' components not just regular resistors and capacitors. As far as the diodes go in the VexUs circuit the jury is still out as to what's best ... series LV diodes or the HV ones. I just like small, convenient packages. I think the parallel diodes can be heat sinked to take care of any heat issue. As I said, I'm working to somehow come up with criteria for rating the components we need for the VexUs circuit.

Peace.

Greg

[jstadwater]

Thanks Greg, for that info.

The light you just shed on the subject made my room brighter! Great explanation for the 22uf multiple caps, I had not thought of doing it that way, makes much more sense. So, if I can get better results (which I have witnessed) with lower capacitence and higher voltage, I could use 4 caps of 11uf, fast cycle, rated for 500V, (if I can order that) wired series and then parallel, and have a handling capability of 1000 volts? I would probably be safe then to use the voltage doubler circuit which actually takes the measurable voltage close to 300V. OBVIOUSLY we don't need amperage here anyway, just the voltage potential. Maybe I could also fashion a little box with a couple heat sinks and a small fan to mount the caps, resistor, and the diodes into. Thanks for the part # of your FWB too, I need to order some of those today along with a couple isolation transformers. Do you have a part # for the variable resistor you are using? Would that one still function the same if I charge to 300V? Thanks for everything, later....................................Mike

[jstadwater]

If I use 11uf caps for the main circuit, should I also use 11uf caps in the voltage doubler circuit? And what rectifier diodes are reccomended to use in the doubler circuit? If the doubler circuit replaces the FWB, should the resistor still be wired into the same location it is now? I know, alot of questions again. Later........................................Mike

[gmeast]

Caps

If I use 11uf caps for the main circuit, should I also use 11uf caps in the voltage doubler circuit? And what rectifier diodes are reccomended to use in the doubler circuit? If the doubler circuit replaces the FWB, should the resistor still be wired into the same location it is now? I know, alot of questions again. Later........................................Mike

Hi,

On fropping the cap value that's correct, much faster cycle time for the same R1. I hve no experience with ladder-type voltage doublers so I can't advise but I know the cap value has something to do with its current carrying capacity. As the ladder increases voltage it decreases amperage. Aaron introduced me to ladder doublers but I still haven't made one yet.

It is reasonable to assume that at some point too much voltage might send the thing into a continuous arc if the CDI cap size isn't drastically reduced and R1 increased so that the big cap doesn't become a source for a welding arc ... tee hee. The circuit itself has such low inductance (no inductors) there probably isn't a chance for a resonance problem.

Anyway, I'm running mine completely on battery and inverter now. No conflicts .... yippy!. BTW, I was also astounded when I first ran my VexUs circuit ... I remember saying to myself "$@%$!, this thing really works... ".

Peace,

Greg

[lapperl]

Heatsink w/fan

jstadwater,

Here are a couple of links for some inexpensive heat sinks and fan. These would be nice to cool an enclosure.

Just thought it might help.

Lapperl

Foxconn Aluminum Intel PIII Socket 7, PPGA & FC-PGA CPU Cooler w/ Heat Sink-Best Computer Online Store Houston Buy Discount Prices Texas-Directron.com

Newegg.com - MASSCOOL 5C12B3 50mm Ball CPU Cooler - CPU Fans & Heatsinks

[xpskid]

Hi,

On fropping the cap value that's correct, much faster cycle time for the same R1. I hve no experience with ladder-type voltage doublers so I can't advise but I know the cap value has something to do with its current carrying capacity. As the ladder increases voltage it decreases amperage. Aaron introduced me to ladder doublers but I still haven't made one yet.

It is reasonable to assume that at some point too much voltage might send the thing into a continuous arc if the CDI cap size isn't drastically reduced and R1 increased so that the big cap doesn't become a source for a welding arc ... tee hee. The circuit itself has such low inductance (no inductors) there probably isn't a chance for a resonance problem.

Anyway, I'm running mine completely on battery and inverter now. No conflicts .... yippy!. BTW, I was also astounded when I first ran my VexUs circuit ... I remember saying to myself "$@%$!, this thing really works... ".

Peace,

Greg

Hi Greg,

I was able to get into the barn today and build the VexUs circuit.
Everything ran great ! 6 plugs, distributor, points, all firing consistantly at an engine equivelant of 5000 rpm. I haven't gotten any feedback to my call for alternate spark plug geometrys, so I assume noone is working in this area. I thinking I'll throw this in my vehicle and see how it performs.
From your experiences with the bug, can you offer a starting point as to spark gaps ?. Did you go large, stock, middle ?

Regards,

Timm

[xpskid]

Hi Greg,

I was able to get into the barn today and build the VexUs circuit.
Everything ran great ! 6 plugs, distributor, points, all firing consistantly at an engine equivelant of 5000 rpm. I haven't gotten any feedback to my call for alternate spark plug geometrys, so I assume noone is working in this area. I thinking I'll throw this in my vehicle and see how it performs.
From your experiences with the bug, can you offer a starting point as to spark gaps ?. Did you go large, stock, middle ?

Regards,

Timm

Anyone from the Mid-Michigan area ?

Timm

[lapperl]

Not quite Mid Michigan. Tri-County area though.

LapperL

[xpskid]

Not quite Mid Michigan. Tri-County area though.

LapperL

Funny you phrase it that way, I'm from the Tri-City area.

Timm

[gmeast]

gap

Hi Greg,

I was able to get into the barn today and build the VexUs circuit.
Everything ran great ! 6 plugs, distributor, points, all firing consistantly at an engine equivelant of 5000 rpm. I haven't gotten any feedback to my call for alternate spark plug geometrys, so I assume noone is working in this area. I thinking I'll throw this in my vehicle and see how it performs.
From your experiences with the bug, can you offer a starting point as to spark gaps ?. Did you go large, stock, middle ?

Regards,

Timm

Hi,

I bought some solid from a local Bug shop. Gauged them and one was at 0.025 so I set them all to that. No problems yet. Thanks for building the VexUs.

Additionally, I got some Caps from Mouser P/N 598-81LX330M450H012
with the following specs:

http://www.cde.com/catalogs/380LQ.pdf

The pieces I bought are 33uf and tested 5 min. at 2400 rpm on my stock Bug distributor and had acceptable heat. They are Aluiminum Electrolytic and I think that is the 'flash cap' kind. Series-Parallel these might work great. It's the only cap that has 'frequency data' in the data sheet (I've found so far). These types of things are the only ones challenging the VexUs now is component rating ... diodes, power resistors, capacitors. Pin these down and we got it ... on to water.

Peace,

Greg