Water Sparkplug

[demios]

Is this circuit functional and/or useful?

Now, I have to tell you that my knowledge of electronics is pathetic but, I think the principle is sound. So, here's the circuit I "envisioned" that's supposed to increase the 13.5VAC (varies between 13.5VAC and 14.5VAC) off of the car alternator and send it through an isolation transformer (40x) that is connected to the voltage quadrupler and then to the dump capacitor rated at 3000V 680pF (3.06m Joules). The dump cap is not in the diagram:

http://upload.wikimedia.org/wikipedi...quadrupler.svg

Output ranges:

13.5V x 40 x 4 = 2160VDC
14.5V x 40 x 4 = 2320VDC

As I read here: Jochen's High Voltage Page : Basic multiplier circuits we have to use capacitors and diodes that are rated DOUBLE in comparison to input voltage (13.5/14.5 x 40 = 540VDC / 580VDC). That means (just to be sure) 1500V rated caps and diodes for quadrupler construction. I also read that these voltage multipliers can be found in old BW TVs, you can also read that here (under "bridge circuit") Voltage doubler - Wikipedia, the free encyclopedia.

So, my question is, will this aid us in creating plasma spark (piggyback the existing spark, of course)? And, do we need a resistor between the quadrupler and the dump capacitor?

Thanks for your effort guys!

[gmeast]

resistor

Now, I have to tell you that my knowledge of electronics is pathetic but, I think the principle is sound. So, here's the circuit I "envisioned" that's supposed to increase the 13.5VAC (varies between 13.5VAC and 14.5VAC) off of the car alternator and send it through an isolation transformer (40x) that is connected to the voltage quadrupler and then to the dump capacitor rated at 3000V 680pF (3.06m Joules). The dump cap is not in the diagram:

http://upload.wikimedia.org/wikipedi...quadrupler.svg

Output ranges:

13.5V x 40 x 4 = 2160VDC
14.5V x 40 x 4 = 2320VDC

As I read here: Jochen's High Voltage Page : Basic multiplier circuits we have to use capacitors and diodes that are rated DOUBLE in comparison to input voltage (13.5/14.5 x 40 = 540VDC / 580VDC). That means (just to be sure) 1500V rated caps and diodes for quadrupler construction. I also read that these voltage multipliers can be found in old BW TVs, you can also read that here (under "bridge circuit") Voltage doubler - Wikipedia, the free encyclopedia.

So, my question is, will this aid us in creating plasma spark (piggyback the existing spark, of course)? And, do we need a resistor between the quadrupler and the dump capacitor?

Thanks for your effort guys!

Hi demios,

This is worth looking at because a system like this, being tied to the alternator's speed, is proportional to the engine's ignition frequency and thus the power demand from the plasma circuit. The isolation transformer configuration is a natural for the plasma circuit I'm just not sure if it will 'buck' the induction spark. You should still need a resistor R1 between the multiplier and the CDI Cap C1 ... if that's the one you mean. The reason I think you still do is because it will allow the dump cap to mostly empty otherwise the multiplier will keep it filled up and the spark plug will just arc. The resistor could also be replaced by a choke, but I don't know how to design the correct inductor as its replacement ... any takers ? please.

Thanks for posting the information demios. Peace,

Greg

[demios]

Yes, that's the resistor I was referring to. Maybe I should put a variable resistor and try to find a sweet spot, where dump cap will actually dump the charge instead of leaking it slowly. Do you have any idea what range should the variable resistor have?

As far as choke is concerned, I understand the principle, but I know nothing about them, besides that.

[gmeast]

Yes, that's the resistor I was referring to. Maybe I should put a variable resistor and try to find a sweet spot, where dump cap will actually dump the charge instead of leaking it slowly. Do you have any idea what range should the variable resistor have?

As far as choke is concerned, I understand the principle, but I know nothing about them, besides that.

Hi demios,

I know that my system calculates out to 45 watts. I would definitely select 0-500 ohms variable power resistor rated for at least a 100 watts if you want to try to find the sweet spot by 'tuning'. Be advised that as you use less resistance, at some point the arc will SEEM to suddenly get better but in fact is starting to arc and you have gone too far. If you place an oscilloscope across the C1 (cap) you can watch the charge / discharge trace and determine exactly the right resistance for your highest ignition rate (RPM).

Be careful of HIGH VOLTAGE. Good luck,

Greg

[Shane Jackson]

My test setup is using a 22uf C1 and 1ohm R1. Needless to say I am having a lot of plug ware.... I am planning on using a 100ohm R1 and 10uF c1 on the next test setup. Hopefully that will take care of the plug ware issue.......

I'm still holding my breath for some Firestorm plugs.......

[gmeast]

values

My test setup is using a 22uf C1 and 1ohm R1. Needless to say I am having a lot of plug ware.... I am planning on using a 100ohm R1 and 10uF c1 on the next test setup. Hopefully that will take care of the plug ware issue.......

I'm still holding my breath for some Firestorm plugs.......

Hi Shane,

Oh yes, I would say that with 1ohm R1 you are mostly arcing the plug. Can you put a scope across C1 so you can SEE the charge / discharge event(s)? You don't need any more power flowing into C1 than than is required to just charge it up to about 3 or 4 time constants. This can be easily computed for your highest expected ignition frequency ... RPM. On my VW, I'm using 500 ohm and 2 uF. The scope trace below represents 4,000 RPM. The following trace was from an earlier lower voltage oscillator (200 VDC), but everything else is the same. It should look like this:

Onward and upward. Test and refine. Best of luck,

Greg

around 4,000 RPM

[ashtweth]

Guys Naresh has been playing around with an ignition one
ImageShack - Image Hosting :: ignitioncoildioderevdeg0.gif

Ash

[dllabarre]

checking...

Checking to see if this forum is working.
I saw a post yesterday that isn't here now.

DonL

[Robert E.]

Osicilator

Hi Shane,

Oh yes, I would say that with 1ohm R1 you are mostly arcing the plug. Can you put a scope across C1 so you can SEE the charge / discharge event(s)? You don't need any more power flowing into C1 than than is required to just charge it up to about 3 or 4 time constants. This can be easily computed for your highest expected ignition frequency ... RPM. On my VW, I'm using 500 ohm and 2 uF. The scope trace below represents 4,000 RPM. The following trace was from an earlier lower voltage oscillator (200 VDC), but everything else is the same. It should look like this:

Onward and upward. Test and refine. Best of luck,

Greg

around 4,000 RPM

Hi Greg,
I built the oscilator and one 2N3055 runs hot,(with sink), and one runs real cool. I checked the transistors as ok and even checked the gain of each and there about the same. I checked all parts and wireing and there ok. It pulls a little over 4 amps and puts out about 250 volts out of the vexes circuit. I was wondering if you might give me a clue as to what could be causing one 2N3055 to run over 160 degrees. I didn't leave it on but for about 30 seconds at a time. I do have 50 ohms on the bases of the 2N3055's and the 1 uf condensors across the 12K resistors on the other transistors. Any Idea???? appreciated. Bob

[gmeast]

Hi Greg,
I built the oscilator and one 2N3055 runs hot,(with sink), and one runs real cool. I checked the transistors as ok and even checked the gain of each and there about the same. I checked all parts and wireing and there ok. It pulls a little over 4 amps and puts out about 250 volts out of the vexes circuit. I was wondering if you might give me a clue as to what could be causing one 2N3055 to run over 160 degrees. I didn't leave it on but for about 30 seconds at a time. I do have 50 ohms on the bases of the 2N3055's and the 1 uf condensors across the 12K resistors on the other transistors. Any Idea???? appreciated. Bob

Hi Bob,

Yes, I had one a little hotter than the other too. The spec for these reads 200 deg C ! That's allot. I have a fan on the 3055 heat sinks. Mine runs around 500 ma just sitting there. It draws about 6 amps at 4000 RPM. What transformer are you using? Everything is different for various transformers. The picture is of the one I'm using. I had to fiddle with the caps to get the frequency between 80 - 90 Hz. You can hit a 'bad' spot for the transistors withe the wrong transformer.

Greg

[gmeast]

hot again

Hi Greg,
I built the oscilator and one 2N3055 runs hot,(with sink), and one runs real cool. I checked the transistors as ok and even checked the gain of each and there about the same. I checked all parts and wireing and there ok. It pulls a little over 4 amps and puts out about 250 volts out of the vexes circuit. I was wondering if you might give me a clue as to what could be causing one 2N3055 to run over 160 degrees. I didn't leave it on but for about 30 seconds at a time. I do have 50 ohms on the bases of the 2N3055's and the 1 uf condensors across the 12K resistors on the other transistors. Any Idea???? appreciated. Bob

Hi again,

The 12K resistors go from the base of the PNP's to ground. The 1uF caps are by themselves from the PNP base / 12K ohm resistor connection to the opposite NPN's (3055) / 50 ohm / PNP collector connection. The 1uF caps don't actually go across anything. Your 50 ohm resistors are the 220 ohm resistors in the schematic. The 12 k Ohm resistor and the 1 uF cap are only common at the respective PNP's base. This might be the source of your problem.



Greg

[Robert E.]

osicilator

Hi Bob,

Yes, I had one a little hotter than the other too. The spec for these reads 200 deg C ! That's allot. I have a fan on the 3055 heat sinks. Mine runs around 500 ma just sitting there. It draws about 6 amps at 4000 RPM. What transformer are you using? Everything is different for various transformers. The picture is of the one I'm using. I had to fiddle with the caps to get the frequency between 80 - 90 Hz. You can hit a 'bad' spot for the transistors withe the wrong transformer.

Greg

Thanks Greg,
Boy 200 degrees C is a lot of heat. I will play around with it some more with a fan on it and check the freq. closer. My transformer is a Radio Shack 12.6 volt out, with center tap and can put out 3 amps. As this circuit looks like it is symmetrical it is a puzzle as to why one 2N3055 runs different temp than the other. I thought it may be because of the gain of one over the other but they are pretty close. Maybe a matched pair would work better. If I find out more I'll let everybody know. Bob

[insane4evr]

Hi Bob,

Swap the base drive to the 2N3055's. If the hotter 2N3055 gets exchanged then your base drives are not symmetrical. If the hotter 2N3055 remains the same, and you are getting high temp. with the unit un-loaded, then one of the 2N3055 probably has too much collector to emitter leakage current (partial short).

Just my 2 cents.

[gmeast]

better drawing of the exact same circuit I'm using

Thanks Greg,
Boy 200 degrees C is a lot of heat. I will play around with it some more with a fan on it and check the freq. closer. My transformer is a Radio Shack 12.6 volt out, with center tap and can put out 3 amps. As this circuit looks like it is symmetrical it is a puzzle as to why one 2N3055 runs different temp than the other. I thought it may be because of the gain of one over the other but they are pretty close. Maybe a matched pair would work better. If I find out more I'll let everybody know. Bob

Hi Bob,

I drew the specific schematic of the exact inverter circuit I built and also included is a capture of the oscillator running at around 90 HZ at a 45 Watt load. If you can scope it, the oscillator should look similar to the picture.

The scope trace isn't as "square" as I would like it. I could sharpen it up a little more by driving the 3055s' bases a little harder I assume.

Greg

[Jetijs]

BTW, Greg, do you have made any progress with your setup? Any new results?