Water Sparkplug

[gmeast]

oscillator

Hi everyone,

Just posting the oscillator / inverter on the board.

Thanks all for your participation. This thing is quite efficient given the type of circuit and components.

Thanks again pmonk for posting this to begin with.

Peace,

Greg

New and better Oscillator without cooling - free space for two fans for the transformer & 3055 transistors

[Jetijs]

Phil,
I am using a transformer form an old UPS, like this:

[pmonk]

Oscillator

Jetijs,

What kind of transformer is that and where did you get it?

Thanks,
Phil

[gmeast]

Oscillator

Hi everyone,

Nice job on the oscillator Jetijs. I got the same power characteristics you did. I am now transferring the prototype to the circuit board (actually just perf board).

Thanks everyone for chiming in on this effort. This oscillator may also come in handy for other projects as well.

Still working on my Bug's oil cooler breakage fix. Can't wait to put the oscillator to work when I resume testing.

Peace,

Greg

[Jetijs]

Thanks Kinetix
I will do the cap tests tomorrow, because my power supply is now in use. And I will see what I can combine with the resistors I have to get the power rating to 5W

[Kinetix]

I can't wait the results!
Those resistors dissipates at least 4Watts. Yours are way too small, if rated at 2W and will blow up sooner or later... Try at least 5-10W each.
All the best.

[Jetijs]

will try this
So far I have ran a test with 40W light bulb on the output and the transistors get only really warm, but not hot. I can easily hold my finger on them. Than means that there might even be no need for a fan The base resistors get really hot though, I am using 2w resistors. Does someone know what max temperatures can these common resistors handle?

[Kinetix]

Great job, Jetijs!
You have a really big transformer there, mate!

Would you like to try that little trick that I suggested to Greg also? It's about connecting a big "storage" capacitor between the center tap of the primary and ground. Start with, let's say 100uF/25V and increase the value to maybe 2200uF. Each time measure the energy consumption versus the generated energy. Stop when you get the best ratio.
I have seen this setup in a few different oscillators and it seem to improve efficiency.
Best wishes.

[Jetijs]

Hi all.
I today I completed the oscillator circuit. Here is a picture:


It oscillates at about 2KHz. I used MJL21194 transistors as power transistrs, because it is easier to glue a heatsink on them At first I used 56 Ohm base resistors. This made the circuit consume 600mA at 13V in without any load. It was capable of lighting up a 25w light bulb at full brightness, but a 40w bulb light up only at about 80% brightness. So I reduced the base resistance to 41 Ohms. This made the 40w light bulb to light up at full brightness and a 75W bulb to about 60-70% of full brightness. So I guess that this setup can safely power loads up to 50w without loosing voltage. The reduced base resistance did increase the no-load current consumption to 750mA, but that is not a big problem. Now I need to run some load tests for longer periods of time to see if the heatsink can handle the transistor heat, I think that it should handle the heat, but if not, I can always attach a small fan to cool them. Rectified output voltage is 375V at 13V input. I guess that I don;t even need a voltage doubler. I might not even need a storage cap, because the oscillation frequency is high enough
Great simple circuit
Edit: The UPS transformer has three wires on the output - red, yellow and black. I got 375V out from the red and black wire, but then I tried the black and the yellow wire and got 420V This is great

Thanks,
Jetijs

[Kinetix]

Xack, those transistors (Q1 and Q2) have to do two jobs:
- oscillate
- handle a current that varies between 65mA (as in the original setup, with 220 Ohm resistor) and 288mA (as in Greg's setup, with 50 Ohm resistor). I assumed that the circuit is fed with 14.4V from a full charged car battery.
So, for this purpose, you may use any transistor that can both oscillate and handle up to at least 500mA.
I don't think they will switch faster, as this probably depends on the transistor's type also. I made that suggestion in order to help those of you that do not find the parts specified and would like to replace it with something else.
Best wishes.

[gmeast]

Pf24-10

Hi Greg

New here.

Looking at the pdf on the transformer tells me that it is a PF24-24, not PF24-10. PF24-24 gives 24VAC. PF24-10 gives 10VAC (Series connection).
I might be reading it wrong , if so correct me!
Mike

Hi Mike,
PF24-10 gives 10 VAC with a series connection on the secondary, parallel connection on the primary. Secondary wired with center tap as the Input and primary wired parallel as the Output for this thing

Greg

http://home.pacbell.net/gmeast/VW/PF24series.pdf

[Xack]

Scope Capture

Greg,
is your scope set on 50 volts / division? It looks like it's around 350Volts pp. That's pretty good. It looks like it'll be a great place to start from and also have headlights available. I'm wrapping up my order for parts.

Thanks,

Xack

[Xack]

Complementary Components

Kinetix,
You make an excellent point. Since I could not find 2N1305 in my search I saw the complementary component listed in the data sheet for the 2N3055. Do you think a medium power PNP help the function and efficiency? faster switching?

Thanks,
Xack

[gmeast]

diodes

Greg,
Thanks for your response and the information. I finally got my order ready.. or so. I was trying to get the details on the HV Diodes and I could not open up the attachments to the Thread. I found the price between 2000 Volt Diodes and 1000 Volt is a bunch. In your videos your using 2 in parallel. What's the part number and rating. If I could get to the attachments I'd not have to ask you.

Thanks,
Kyle

Well, I am using NTE517 replacement microwave diodes. They are 15KV and 0.535 Amp. I actually have four each per plug. And that's expensive too ... $6.30 ea. ... $100 in diodes alone for my VW Bug @%$&# !. Those who use diode strings have been using N5408 ... 1000V & 3A ... forgot the price.

What was your take on the Scope Capture?

Greg

[sigzidfit]

Why use two when one will do?

I reckon the folks here at energeticforum are gonna expose the eggheads by cutting through the crap with Occam's Razor!

YouTube - MIT Plasmatron - Principles of the Pantone GEET Device

GO TEAM

Peace
PJ