Water Sparkplug

[insane4evr]

I used two parallel strings of eight 1n5408 diodes for each spark plug. That makes one big 8kV 6A diode for each plug. They are pointing in the correct way, I checked it twice. And they are not dead. Any other suggestions would be appreciated
Thanks,
Jetijs.

Maybe string count is too low. Maybe instead of two parallel strings of eight per plug, make it one string of 16 per plug (16KV). Current rating of 3A for one 1N5408 is still higher than four parallel NTE517 (.55 x 4 = 2.2A). So maybe no need to connect the 1N5408 strings in parallel.

Just my 2 cents.

[cowboyrx]

Caps question

Having difficulty finding the exact caps as mentioned in the Vexus schematic.

Can I use the following caps or are there specific ones I need to get?

Snap-In Aluminum Electrolytic Capacitor - 105 Degree 470UF 400V

Aluminum Electrolytic Capacitor 105C General Purpose 450volts 22uF 12.5x25mm 105deg C

[gmeast]

Your tests

Had a full day, but managed to get out and move the VexUs circuit from the bench to my 88 GMC, 2.8L, V6 with Kettering ignition. Everything went great and it fired right up !
No real problems. I was able to verify everything with an external plug.
I have my the diode string (3 parallel 15Kv) mounted on the underside of the hood with connections to the plug wire caps on the top of the distributor. My firing caps are two 47 pF caps in series, yielding the 22 pF suggested. My resistor is 50 ohm, 330W wire wound.
I did fry my digital timing light, but I can't tell if that is related to this circuit.
~10 deg BTDC still seems to be a sweet spot. I did play with idle jets but couldn't find a definitive spot where there was a noticable difference with the circuit on or off.
I don't have insurance on the vehicle at the moment so I couldn't run it down the road.
Probably time to mound some sort of volumetric tank to monitor consumption and possibly different mixtures.

Robust circuit Greg !! Kudos to you

This is too much fun !

Regards,

Timm

Thanks Timm. I appreciate it.

Peace,

Greg

[Jetijs]

Ok, I checked what type of ignition system does my car have. And it is the very basic one with mechanical contact breaker and condenser.
Timm, is your ignition system of the same type?

[xpskid]

Ok, I checked what type of ignition system does my car have. And it is the very basic one with mechanical contact breaker and condenser.
Timm, is your ignition system of the same type?

Yes Jetijs,

I'm using the same type.
I'd have to assume your condenser is still good since it runs without the diodes and since the diodes are on the plug side of the distributor, it shouldn't see the compressed spark.

Timm

[boxley55]

Would it help if you add a diode to prevent the 2 separate circuits from feeding back on each other? (the positve to the bottom of the spark plugs).

Can you isolate diode strings ? I have plugs on both ends of my strings in case I need to replace any. Just curious if you could isolate one string at a time to see if that would shed any light on it.

Timm

[jstadwater]

A possible solution......

Hey Jetijs,

I was looking at your schematic for a bit this morning. I noticed you said your ignition system fires HV negative, if that's the case, you need to reverse the pos and neg hookups from the capacitor to the plugs and engine block. You also need to reverse the direction of your diode banks. You have the anode (+) facing away from the plug, if you are firing HV neg it needs to be turned toward the plug. I know this seems backward, but my ignition fires HV pos and it works exactly the way your diagram is wired. The main thing to check, from my own trial and error, is that the plugs still fire normally with the 110V turned OFF while everything is hooked up. When everything is hooked up (and no 110V turned on) and you get the itsy, bitsy, teeny, weeny, normal spark on the plug......you're good to go with flipping on the 110V. Hope this helps solve the problem for you............................................Mik e

The diodes I used in my vid are a single 12KV 350mA for each cylinder.

[jstadwater]

Oil filled caps.................

So, there is definitely lower capacitence with these caps, but will it create a problem for us to only charge them at a few hundred volts? Most I have seen are rated for a couple thousand volts. I want to try one that I have here, it's a 1.06 uf 1750 VAC. They all say AC and 60hz, will they blow up if I hook them to DC voltage? I guess I'll know if I hook it up and it smokes, right? Wish me luck..........................................Mike

[Gibs]

Oil filled capacitors

Gibs,

Tenth of a uF ? I've got a few oil filled 32uF, 2500V cans.
Dang, I wish I could find a reason to use them, They're monsters ! (physical dimensions)

Timm

Hi Timm,
Interesting, I am wondering how big they are!

First thing I would try with a monster can like these would be to charge one up with a MOT (about 2kV) and discharge it in a .015" spacing spark gap immersed in distilled water.
Wow man, what a bang it would give.
Then I would measure the residual voltage left in the cap to know the exact amount of energy used to explode water.

By the way, what where they used for?

So, there is definitely lower capacitence with these caps, but will it create a problem for us to only charge them at a few hundred volts? Most I have seen are rated for a couple thousand volts. I want to try one that I have here, it's a 1.06 uf 1750 VAC. They all say AC and 60hz, will they blow up if I hook them to DC voltage? I guess I'll know if I hook it up and it smokes, right? Wish me luck..........................................Mike

Hi Mike,

You might be able to charge these oil filled caps with DC without any problems under the max rated voltage. Polarized capacitors works only with DC, but AC ones can take both DC and AC.

Keep up.

[jstadwater]

Thanks Gibs,

I just tried the 1.06 uf oil cap in my circuit, worked fine and didn't even think about heating up firing my circuit at 2,300 rpm. Of course, the spark was way less than with the 22 uf cap at same 110 voltage.

Now for the voltage doubler circuit, the caps and diodes used should be rated MORE than the expected output voltage, correct? What about the capacitence of the caps? Currently we are using a 470uf storage cap at the FWB, would that need to be cut down to less than half of the uf rating of the caps in the doubler circuit so the inrush of voltage to charge the storage cap doesn't fry the doubler circuit? If anyone knows about this, I would be greatly appreciative.Later................................ .....Mike

[dllabarre]

testing a MOT

This might seem like a trivial question to most here but....

I got my hands a on Microwave oven transformer and capcitor.
I wanted to test to make sure it even works so I connected a 12V battery to the primary.
But I don't get any voltage reading out of the secondary?

Is this a fair test or isn't a 12V battery enough of an input?

How is a good way to test the MOT?

Thanks
DonL

[jstadwater]

Good VexUs News..................

I just ran a test with the voltage doubler circuit installed. My max rpm on the V-8 distributor, drill spun, is 2,300 rpm as previous. Voltage doubler is set up as follows: A pair of 120uf 330V flash caps and a pair of 1N5408 diodes. The measurable DC voltage out is 326 volts, I think the caps need to be rated for 400V instead, I just had these laying around. The discharge cap is a MW oil filled 1.06uf rated for 1,750V. NO misfires at 2,300 rpm, nice crisp sparks and no cap heating detected. If I could only find one of these oil filled caps at say....10uf. I wonder how good the spark would be with that bad boy! I am in the process of setting up an electric motor (variable speed) so I can see how fast the plasma spark will crank out with my present configuration. Will post results as soon as I finish the test run. VERY EXCITED, later......................................Mike

[insane4evr]

This might seem like a trivial question to most here but....

I got my hands a on Microwave oven transformer and capcitor.
I wanted to test to make sure it even works so I connected a 12V battery to the primary.
But I don't get any voltage reading out of the secondary?

Is this a fair test or isn't a 12V battery enough of an input?

How is a good way to test the MOT?

Thanks
DonL

Hi dllabarre,
Transformers will give you a continuous output only if your input is AC and not DC. 12 volt battery is DC, so no continuous output. You will get only a short duration spike output at the moment of DC connection and short duration higher spike output at the moment of DC disconnection.

In short, you need to test with AC voltage. Watch out for lethal voltages.

[dllabarre]

Hi dllabarre,
Transformers will give you a continuous output only if your input is AC and not DC. 12 volt battery is DC, so no continuous output. You will get only a short duration spike output at the moment of DC connection and short duration higher spike output at the moment of DC disconnection.

In short, you need to test with AC voltage. Watch out for lethal voltages.

Thank you,

What if I used pulsed DC input?
How much pulsed DC voltage would I need to see output on the secondary of a MOT or won't it work?

DonL

[Jetijs]

Hi all.
Today I tried the vexus circuit on my car again. This time I increased the number of 1n5408 diodes in the string to 16 and I used only one string per spark plug. This time there was no problems. The engine started good and the light bulb went bright. So if you use a number of low voltage diodes, make sure you have at least 12 of them in a string. As soon as I turned the variac ON, I could hear a minor increase in the idle RPM's that went back to normal when the variac was turned OFF. But that minor change is barely hearable, nevertheless it is there. Also judging by the light bulb flashes on each spark pulse, I could tell that there are some pulses when the booster effect did not appear also the engine chokes a bit on those moments. I suppose that that is because of the circuit breaker wearout that causes missing original spark. Will install the inverter and isolation transformer now and take the car for a test run

jstadwater, this time I also used the same setup as in previous test, I did not reverse the diodes, so if that circuit works for you, that must mean that you also have a negative HV output from the induction coil.

Anyway, thank you all for suggestions and help