The Spark-O-Matic - Wire Arc Welding for coil making

[bapgood]

Nice touch w/ the stationary post. I find it a lot easier to get a parallel tack weld when I secure one end in my "Helping Hands Soldering Aid" which I show using in the last video. Less hand shaking.

Just my 2 cents. You may want to rethink the screw terminal for something different. It may most likely nick the wire and weaken it.

Good thought....I bought a pack of the brass alligator clips from radio shack. Maybe I'll try fixing one of those vertically.

[bapgood]

Ok JW.....I have three caps (Fuji AAA, 100uF, 120uF)





Are you using a cheap dmm?

When using a harbor freight $4 cen-tech dmm I also get a fast leak. Way fast.....not usable fast 

When using a $20 harbor freight cen-tech its a lot more stable. It still drops off, but very slowly. Slow enough that once you get it set you should be able to weld before it drops any...maybe a tenth of a volt or two if you had to fumble with things.

I was going to bring home a good fluke dmm from work and forgot, but I wonder if you will ever get a dead solid reading with any dmm.

The only other thing I wondered about and haven't tried is that I completely strip everything not used off the pcb, including the flash.

[Breaktru]

soldering the caps makes no difference that i can tell....hmm, still seems to be the same drop.

baps, can you try and see if youre experiencing the same voltage drop with the flash boards and a few caps?

VoltMeter Input Impedance:

With my good DMM from the videos on 1000VDC scale, my voltage does not show any noticeable voltage drop.

I hooked up an old Cheap-o DMM that may have cost 5 bucks, the voltage drops considerable on all VDC ranges. So I'm assuming the impedance on this junk is low.

I tried a cheap Anolog and it was rock solid on all VDC scales. Even though Anolog meters are generally low impedance input.

So.......... I would bet it's your meter that's draining the cap do to low impedance input rating.

In general, the meter's input impedance should always be much higher than the source impedance of the device under test. When evaluating input impedance of a multimeter the higher the value the better. Fluke is rated at 10M

Also see: how to measure the internal resistance of a voltmeter?

Take a battery (AA) measure the voltage. Measure a resistor (1M) and put it in series w/ the battery. Measure the voltage after the resistor and use these results in the calculator in the link below....
Here is the calculator the check your Input Impedance: Excel Calculator
Formula: DMM internal resistance in megaohms= ("DMM voltage measured " x "value of resistance used in megaohms") / ("input voltage" - "DMM voltage measured ")

[bapgood]

Breaktru....I want the link on how to increase the impedance of HF $4 dmm 

[Breaktru]

I just checked two meters with this formula spreadsheet: DMM IR Calculator

Input Impedance
My good meter is 10M
EL-Cheap-O is 1M

[Papa Hoyt]

I know the circuits design was for an input of 1.5V from an alkaline but has anyone tested the V threashhold? maybe doubling the AAs into 3V or even A 3.7LiIon?

[Papa Hoyt]

What I am getting at is if we can up the input Voltage then we could reduce charging times on larger capacitors

[bapgood]

I might know that 9v is no bueno 

That's what happens when you buy 9v battery tabs

[Papa Hoyt]

I might know that 9v is no bueno 

That's what happens when you buy 9v battery tabs

Yeah a 6X bump in voltage is not really what I had in mind but I would imagine the magic smoke show was nice for a minute

[bapgood]

I'm going to give 3.3v a try from a pc power supply.

I have aspirations to build the ultimate aty station with:
- Spaaaahkk-o-matic Welder with volt display
- Ohm test leads and display
- VV Multi aty break in/test stations with fan assist.

[Breaktru]

I think you would damage the circuitry. It was designed for 1.5v.
Now if you want to increase the charge time, replace the AA with a C or D cell. Don't know why you would want to unless you have a super large capacitance. It's relatively quick enough to go from 0 to 75v.

[Papa Hoyt]

Was just thinking that maybe a bank of capacitors or one fatty might give more stable amperage at lower voltages and better heat to the weld. Maybe i am over thinking this.

I have an adjustable regulator board that I could use that is capable of 3A output so this would speedup the charge and soak time as well. i call it soak but that may be an incorrect term for the amount of time that it takes the capacitor to sabilize V. i have had 0 classes on this and only limited working knowledge.

[Papa Hoyt]

Been looking for capacitors on fleabay and am kinda surprised they have a selection from 50uf to 1400uf in the 330V class

[Breaktru]

I have this Spark-O-Matic thing down pretty good w/ just an AA battery and 340uF capacitance. I've achieved 98% success on the first weld.
We are welding thin wire to thin wire. I don't really see a need to go any further in circuit modifications. Aesthetics is good. I like what bap did on his design and Warlion did a bang up job on his build and video.
I have these parts coming for a DC-DC converter welder but why when this is working so well for me.

[bapgood]

I'm close.... Just gotta get back to the bench and weld some wire. I'm ok with the AA and the time to charge the capacitors.

[Papa Hoyt]

I have this Spark-O-Matic thing down pretty good w/ just an AA battery and 340uF capacitance. I've achieved 98% success on the first weld.
We are welding thin wire to thin wire. I don't really see a need to go any further in circuit modifications. Aesthetics is good. I like what bap did on his design and Warlion did a bang up job on his build and video.
I have these parts coming for a DC-DC converter welder but why when this is working so well for me.

like I said, maybe I was over thinking it. Maybe my ideas would work better as the tab welder you mentioned earlier.

[Breaktru]

like I said, maybe I was over thinking it. Maybe my ideas would work better as the tab welder you mentioned earlier.

Exactly... but hey it's your build so if you want to try something different, go for it. I was fooling around before the spark-o-matic with a large capacitor and a large 12v Gel Cell battery and it made mean sparks.

[WarLion]

today i get another kodak camera and this one the cap said is 330vs 80uf  but is so hard to find here 330v caps

[rrtwister]

today i get another kodak camera and this one the cap said is 330vs 80uf  but is so hard to find here 330v caps

Hey WarLion, cool video 
If you are using a camera board from say Kodak. Wouldn't it be practical to use the extra cap or two from another Kodak camera.
And the same goes for Fuji. Fuji board cap with another Fuji cap. This way your doubling or tripling the capacity and using the same components.

[MidnighToker]

I can NOT get any consistent welds from this.  Tried adding one then 2 100uf 50v caps but then the charge maxes out @ 75 volts.  Still get a decent weld from that but it's still inconsistent.  Gonna have to go hunting for some larger caps I guess.

[Jellyfish]

I can NOT get any consistent welds from this.  Tried adding one then 2 100uf 50v caps but then the charge maxes out @ 75 volts.

I'm still waiting for some parts, but from what I understand it looks like the voltage on your caps is too low. I'm waiting for some caps that are rated at 350 V but I think that Breaktru indicated 330 V which is the same rating as the cap on the Kodak board that I have.

[Breaktru]

I just came from Costco and I got 10 Kodak spent cameras. Opened up 6 and found different caps and boards.
I have 80, 100, (3) 120 and a 160uF caps. Two of the 6 had shot film in them.

[Papa Hoyt]

I can NOT get any consistent welds from this.  Tried adding one then 2 100uf 50v caps but then the charge maxes out @ 75 volts.  Still get a decent weld from that but it's still inconsistent.  Gonna have to go hunting for some larger caps I guess.

Because you are using 50V capacitors, you are lucky to get 75V form that. get 330V caps

[MidnighToker]

Because you are using 50V capacitors, you are lucky to get 75V form that. get 330V caps

Kinda about what I figured.  Guess the voltages averaged out between the caps (one on board is unmarked and I can't get a clean read from it).  Think I'm going to scrifice one of the odd flash assemblies and use the cap off that to see if it will stabilize.

[Breaktru]

Kinda about what I figured.  Guess the voltages averaged out between the caps (one on board is unmarked and I can't get a clean read from it).  Think I'm going to sacrifice one of the odd flash assemblies and use the cap off that to see if it will stabilize.

The voltage of the cap has nothing to do with how it's working. It's safety. You will most likely BLOW the cap and if not monitored, 300+ volts on 35v cap can be quite startling if not dangerous and may cause a fire. Even 75v will do it.

Take the caps off of the other camera circuits you have. Try to get a total of 320, 340 or 360uf. Start w/ 70v and work up a volt at a time for each weld. Cut both ends off of an unsuccessful weld and try again.
Don't attempt a weld if the voltage is dropping. You need a maintained voltage.

Shaky hands or an irregularity in the straightness of the wire spot to be welded will lead to failure. Lock one probe in a stationary clamp/vise/stand and for the second probe, lean your hand on something stable. Use magnification, over lap the wires. Before charging cap, over lap the two wires to be welded and see what it looks like.

Update: Instead of overlapping the wires, try the BUTT WELD TECHNIQUE

[bapgood]

Here she be....well the first one anyway

[CraigHB]

There's some good videos of exploding capacitors on youtube.  Doesn't take all that much over the rating for that to happen.  Here's one;

http://www.eevblog.com/2009/11/04/eevblog-42-exploding-capacitors-in-high-speed/

[Breaktru]

There's some good videos of exploding capacitors on youtube.  Doesn't take all that much over the rating for that to happen.  Here's one;
http://www.eevblog.com/2009/11/04/eevblog-42-exploding-capacitors-in-high-speed/

Nice... good find. I like his videos

[Breaktru]

Here she be....well the first one anyway

Good going Bradley. Now your in business.

[Breaktru]

Do to security, I can only post 3 URL links at a time.

Key Points found in this thread:

Tips for a successful weld

Wire Schematic/Diagram

Use Caution

[Breaktru]

Setting Cap Charge

Learning Curve

Rehash - Stable Voltage

[Breaktru]

Adding More Caps

Magic Number

Arc Welding in Action

[Breaktru]

Why is my voltage dropping?

[beamrider]

These kind of circuits are handy for all sorts of things.  One of these days I need to build a really beefy one, that's adjustable for output.  Spot welding is a good way to tack something together temporarily , and you can find all sorts of uses for a  quick  burst of high voltage like that.  Putting solder tabs on  batteries, de-whiskering old nicads, all sorts of stuff.

[MidnighToker]

There's some good videos of exploding capacitors on youtube.  Doesn't take all that much over the rating for that to happen.  Here's one;

http://www.eevblog.com/2009/11/04/eevblog-42-exploding-capacitors-in-high-speed/

Nice!

I've popped more than my share of them over the past few years.  Nothing quite as spectacular as the last one on there though.  Only takes a small slip with a probe and POP!

[Breaktru]

Nice!

I've popped more than my share of them over the past few years.  Nothing quite as spectacular as the last one on there though.  Only takes a small slip with a probe and POP!

How are you making out w/ your welding?

[WarLion]

ok this mine

using a kodak camera with a single cap of 80uf
best welding using 32awg nickel and 32awg kanthal best voltage was 120v
the voltage drop very quick

using a kodak camera with dual cap one 80uf and other 120uf
best welding was at 75v - 50v 32awg nickel -32awg kanthal
the voltage drop slow

i dont think i will add a third cap this work perfect im happy with only 200uf

[Breaktru]

ok this mine

using a kodak camera with a single cap of 80uf
best welding using 32awg nickel and 32awg kanthal best voltage was 120v
the voltage drop very quick

using a kodak camera with dual cap one 80uf and other 120uf
best welding was at 75v - 50v 32awg nickel -32awg kanthal
the voltage drop slow

i dont think i will add a third cap this work perfect im happy with only 200uf

Good WL, Thanks for posting.

[MidnighToker]

How are you making out w/ your welding?

Finally got to sit down at the bench for a bit.  Did get is working consistently using 3 caps (2 unmarked...that I can read...and one 80uf).  Still flaky around 75 volts so jumped to about 90 and have been hitting a clean weld with pretty much every shot. (Yeah, I broke down and used the "helping hand" for the one end and magnifier...but my ass isn't getting zapped anymore either LMAO  Now I know how my dog feels when he hits that Invisible Fence...)

Thanks for all you help and tips man.

[Breaktru]

Found this Photo-Flash Capacitor for a buck at: AllElectronics

Also found the Flash board circuits for a buck at: FLASH ASSEMBLY

Update:
Found another Photo-Flash Cap: Another Cap

[bapgood]

Since no one has mentioned it there is probably a reason, but I'm going to throw it out and let the more informed educate me.

Is there a reason why the camera flash circuits couldn't be used with a larger capacity slower discharge capacitor and limit the voltage being applied to 35v/etc to the capacitor?

The LM2577's are cheap enough, but the cameras can be free and I have a few to experiment with.

[MidnighToker]

Found this Photo-Flash Capacitor for a buck at: AllElectronics

Also found the Flash board circuits for a buck at: FLASH ASSEMBLY

Dude...that is an awesome find!

Best I could find on just 100-150uf caps was ~$3  Then still had the rest of the circuit to source...

[Breaktru]

Since no one has mentioned it there is probably a reason, but I'm going to throw it out and let the more informed educate me.

Is there a reason why the camera flash circuits couldn't be used with a larger capacity slower discharge capacitor and limit the voltage being applied to 35v/etc to the capacitor?

The LM2577's are cheap enough, but the cameras can be free and I have a few to experiment with.

Yes you can. Example:
I made great welds with a 1000uF cap at 36v and with a 2200uF at 26v.
Does it matter what we use and at what volts? The job is done and the welds look similar.
If you want to buy parts than go ahead and do so... or go the cheapest route. Use what you have.

P.S.
I don't find the need to clean off the wires w/ alcohol any more. Just a tight and short connection will do it.

Update on capacitance and voltage:
I settled on using 340uF and at 74v - 76v

[bapgood]

Yes you can. Example:
I made great welds with a 1000uF cap at 36v and with a 2200uF at 26v.
Does it matter what we use and at what volts? The job is done and the welds look similar.
If you want to buy parts than go ahead and do so... or go the cheapest route. Use what you have.

P.S.
I don't find the need to clean off the wires w/ alcohol any more. Just a tight and short connection will do it.

I have 1000uF 50v caps and I'm worried about applying to much voltage. Any suggestions to limiting that cheaply and easily?

If I understand correctly the LM2577 welders use a higher capacity capacitor that release the discharge slower and at a lower voltage. Basically creating a longer duration weld. I'm just trying to mimic that with the camera flash.

[Breaktru]

I have 1000uF 50v caps and I'm worried about applying to much voltage. Any suggestions to limiting that cheaply and easily?

If I understand correctly the LM2577 welders use a higher capacity capacitor that release the discharge slower and at a lower voltage. Basically creating a longer duration weld. I'm just trying to mimic that with the camera flash.

The LM2577 does not discharge slower. A short across the cap is a short across the cap no matter what you are using to charge it with.
I used 50v caps and only went as high as 40v. 27v and 36v worked great. As far as limiting the max. I'd have to look into it.

[bapgood]

The LM2577 does not discharge slower. A short across the cap is a short across the cap no matter what you are using to charge it with.
I used 50v caps and only went as high as 40v. 27v and 36v worked great. As far as limiting the max. I'd have to look into it.

Easy on the button for now then

So to clarify my muddled understanding....would there be a difference in using an LM2577 and 1000uF cap at 36V than a camera flash circuit with a 1000uF cap at 36V?

[Breaktru]

No matter what device that you are using to make welds, the important thing to do is to make sure the wire is TIGHTLY held in the clips.
Use quality clips with a strong spring tension. Keep the exposed wire short. And also important is your KNACK of touching the over-lapped wires together.
I've seen crappy welds with the Tsaf when Diver was first using it. He eventually perfected his hand skill.

[bapgood]

No matter what device that you are using to make welds, the important thing to do is to make sure the wire is TIGHTLY held in the clips.
Use quality clips with a strong spring tension. Keep the exposed wire short. And also important is your KNACK of touching the over-lapped wires together.
I've seen crappy welds with the Tsaf when Diver was first using it. He eventually perfected his hand skill.

I agree....and I am perfectly happy with my 340uF welder....I'm just waiting on good NR wire

And you already answered my question with "a short across a cap is a short across a cap" regardless of LM2577 or camera flash.

I have been trying to come up with something to eliminate the human element, but haven't come up with anything good yet.

[Jellyfish]

The LM2577 does not discharge slower. A short across the cap is a short across the cap no matter what you are using to charge it with.
I used 50v caps and only went as high as 40v. 27v and 36v worked great. As far as limiting the max. I'd have to look into it.

Hi Breaktru, I'm a moron at this stuff...but I'm good at following directions and I know how to solder. But I've been piecing info together from here and the other forum. Over there, someone mentioned the use of a Zener Diode to sort of limit voltage. Could something like that be used with the camera boards and 50 V caps to safely limit the voltage?

[Breaktru]

Hi Breaktru, I'm a moron at this stuff...but I'm good at following directions and I know how to solder. But I've been piecing info together from here and the other forum. Over there, someone mentioned the use of a Zener Diode to sort of limit voltage. Could something like that be used with the camera boards and 50 V caps to safely limit the voltage?

You can make a Zener Voltage Regulator using this calculator: Zener Calculator