Resistance-No Resistance wire welder

[Vapid1]

I have noticed that different people are working with different circuits. I have found the following schematics, and it seems like the fuji has a charge button that you need to hold, while the Kodak has a one touch charge button that you can release, and the charging continues.

There also seems to be two schools of though on how to get the correct voltage. The fuji boards can "pulse" to get the desired voltage, checked on a meter. The Kodak models, which I'm currently using, needs to be regulated. Some kodaks use a Zener Diode, and I'm working on varying the value of this, to have the voltage regulated at a predetermined value. A led, with proper resistors, can serve as a indicator that the cap is charged, and ready to weld.

For simplicity, and not needing a meter, I'm currently working on the Kodak Zener boards. I'd like to give some of these to friends, and can't afford to give away meters....

More info to follow...

 

[Vapid1]

Schematics

 

[Vapid1]

One more...

 

[dsy5]

Since we're sharing pictures of the box, I thought I would share mine...



Charge button on left; discharge button on right. Alligator clip removable to use standard leads. Fuji board with (1) 330µF cap and a 10kΩ resistor in series to slow the charge rate, thus avoiding over-shoots.

 

[dsy5]

I've been toying with the idea of using a comparator 741 op-amp with 4 pots and a 4 position selector switch. The op-amp would drive a MOSFET to charge the cap and would cut off when a voltage determined by the pots was reached. It would require a 9 V battery and an additional board, so it would not fit in the original box, though, since it's fairly packed now.

The pots could be adjusted to different voltages and chosen with the selector switch.

But, as breaktru has said before, it is easy enough to tap the charge switch a few times. I may just breadbord the circuit to see if it could work...

 

[breaktru]

Since we're sharing pictures of the box, I thought I would share mine...
Charge button on left; discharge button on right. Alligator clip removable to use standard leads. Fuji board with (1) 330µF cap and a 10kΩ resistor in series to slow the charge rate, thus avoiding over-shoots.

Congrats! Nice and simply. It's all we need.

 

[TBinAZ]

Needs an LED module to make it self-contained. Nice one, dsy5. I'm going to see what I can fit in mine for an LED. Should work. I really like that 10k in series.

I think I got it through my thick skull that less voltage is needed to melt the silver to the Kanthal, and not melt the two together. Still not sure why it was working for me for a day.

Congrats! Nice and simply. It's all we need.

 

[dsy5]

I have been using pure nickel wire - it welds very well to Kanthal and Nichrome. I have some silver, but it is 24 ga and a little thick to work with in my atties.

As a note to all, not everyone will have the same voltage requirements - depending on the cap size, there is more charge available with larger caps. I am currently using from 35V to 60V when welding - and I put a larger cap on my Fuji board.

 

[gsa]

Well, my second LM2577 board came today from here LM2577 3A DC Step Up Adjustable Breadboard Module Power Supply Converter USA | eBay

I only had enough time to hook it up to the breadboard circuit I made last go around with the 3.6ohm 10w resistor, 18650 AW battery and 2amp fuse but I was able to verify that I was boosting from 4.15v to 35v. I have half a dozen 1000uf 50v caps here so hopefully tomorrow I will have a chance to make my v2....(actually it was my v1 and then I got distracted by cameras )

 

[dsy5]

Well, my second LM2577 board came today from here LM2577 3A DC Step Up Adjustable Breadboard Module Power Supply Converter USA | eBay

Just ordered one for myself - even if I don't use it for a welder, it would be a handy thing to have around, especially for six bucks!

What is the value of the adjustment pot? If I use it for a welder I want to put a rotary selector switch in it to select various wire types/sizes.

 

[gsa]

OK, the LM2577 welder is the cats meow. Pics and part list to follow soon. A couple things to note if you have built a camera welder or are thinking of it:

1. There is zero chance of overshooting your voltage target, set the regulator at 35v and that's what you get. The cap takes about 4 seconds to fully charge (sound familiar?) and after that you are not doing anything by keeping the button pressed. This means you only need a dmm to check the voltage the first time you set it up or if you need to use the trim pot to adjust the voltage.

2. Less volts with a higher uf cap means less sparky. I can actually see during and after welding. There is no loud snap, this is overall a pretty civil way to join wires, I will have to find another way to embarrass my wife in front of her friends.

3. Welds are much, much easier to produce. I can't state this enough, if you learned to weld wires with the camera welder, you will be a pro the first time you weld at 35v 1000uf.

4. The welds are stronger, the "overlap" is fully welded, not simply "tacked".

Note: My board limits voltage to 35v max, I am welding 32g nickel NR to 32g and 34g kanthal. If you have different wire sizes, combos there is likely going to be a slightly different voltage requirement. I do have some 30g and 28g kanthal as well as some 30g silver I will try later to try and get a feel for what those voltages might be.

 

[JazzyTech]

OK, the LM2577 welder is the cats meow. Pics and part list to follow soon. A couple things to note if you have built a camera welder or are thinking of it:

1. There is zero chance of overshooting your voltage target, set the regulator at 35v and that's what you get. The cap takes about 4 seconds to fully charge (sound familiar?) and after that you are not doing anything by keeping the button pressed. This means you only need a dmm to check the voltage the first time you set it up or if you need to use the trim pot to adjust the voltage.

2. Less volts with a higher uf cap means less sparky. I can actually see during and after welding. There is no loud snap, this is overall a pretty civil way to join wires, I will have to find another way to embarrass my wife in front of her friends.

3. Welds are much, much easier to produce. I can't state this enough, if you learned to weld wires with the camera welder, you will be a pro the first time you weld at 35v 1000uf.

4. The welds are stronger, the "overlap" is fully welded, not simply "tacked".

Note: My board limits voltage to 35v max, I am welding 32g nickel NR to 32g and 34g kanthal. If you have different wire sizes, combos there is likely going to be a slightly different voltage requirement. I do have some 30g and 28g kanthal as well as some 30g silver I will try later to try and get a feel for what those voltages might be.

Woot! Thanks for the info! Really looking forward to seeing the schematics and building one from scratch

 

[jmarkus]

OK, the LM2577 welder is the cats meow. Pics and part list to follow soon. A couple things to note if you have built a camera welder or are thinking of it:

1. There is zero chance of overshooting your voltage target, set the regulator at 35v and that's what you get. The cap takes about 4 seconds to fully charge (sound familiar?) and after that you are not doing anything by keeping the button pressed. This means you only need a dmm to check the voltage the first time you set it up or if you need to use the trim pot to adjust the voltage.

2. Less volts with a higher uf cap means less sparky. I can actually see during and after welding. There is no loud snap, this is overall a pretty civil way to join wires, I will have to find another way to embarrass my wife in front of her friends.

3. Welds are much, much easier to produce. I can't state this enough, if you learned to weld wires with the camera welder, you will be a pro the first time you weld at 35v 1000uf.

4. The welds are stronger, the "overlap" is fully welded, not simply "tacked".

Note: My board limits voltage to 35v max, I am welding 32g nickel NR to 32g and 34g kanthal. If you have different wire sizes, combos there is likely going to be a slightly different voltage requirement. I do have some 30g and 28g kanthal as well as some 30g silver I will try later to try and get a feel for what those voltages might be.

can't wait to see your masterpiece and here about silver.

 

[BJ43]

Have one of these I haven't put into a Box mod yet. Should work.. Now to get some caps.
DC 4 5 32V to 5 42V Wide Voltage Regulator Step Up Converter Boost Power Supply | eBay
And one of these meters
http://www.ebay.com/itm/Slim-Digita...327?pt=LH_DefaultDomain_0&hash=item1e7672749f

 

[dsy5]

Have one of these I haven't put into a Box mod yet. Should work.. Now to get some caps.
DC 4 5 32V to 5 42V Wide Voltage Regulator Step Up Converter Boost Power Supply | eBay

That converter looks pretty good, too. Has the higher volts needed for thicker wire. It would work well with 2 18350 batteries in series.

Too bad it is from China, though, they are about ready for their holiday...

 

[BJ43]

That converter looks pretty good, too. Has the higher volts needed for thicker wire. It would work well with 2 18350 batteries in series.

Too bad it is from China, though, they are about ready for their holiday...

I got mine a few months ago and will power it from one of my 12v 5 amp sources I use on all my PTs.
What cap would you recommend and should I use one or multiple caps. I really don't mind the size of this as I won't be carrying it around.

 

[bapgood]

Awesome gsa! Now what am I going to do with all my cameras??? Maybe a home shock security system

 

[dsy5]

I got mine a few months ago and will power it from one of my 12v 5 amp sources I use on all my PTs.
What cap would you recommend and should I use one or multiple caps. I really don't mind the size of this as I won't be carrying it around.

I would say that anywhere from 1000µF to 2000µF at 50V should be good. With the supply that gsa has: if a DPDT switch was added and a second cap, you could throw a switch which would series tie the 2 charged caps together - effectively doubling the output voltage.

 

[Lentulusbatiatus]

I've made a simple one after reading these threads, the cap in the camera I used was only 80uf so I didn't have much hope starting out but it works great, 2 secs charge and perfect weld. I love these kinds of threads

 

[gsa]

Schematic with digikey part numbers. To that BOM you also need the LM2577 board, some alligator clips, some wire and solder and a box. The digikey list is about $7, the LM2577 another $7 and then the other misc supplies is going to bring it to around $25 with shipping.

30g silver to 32g or 34g kanthal was a piece of cake at 35v. I am building this at work so that's all the wires I have here, I will try the 28g kanthal when I get home.

Also, I tested the current draw on the battery and it is about .2A

You can see the trim pot for voltage adjustments in pic 3. I used some loctite to secure the board to the side of the box, everything else is hot glue.