I want to build the battery tab welder as described here
http://www.philpem.me.uk/elec/welder/

I am trying to locate all the parts I need via his schemtaic located here
http://www.philpem.me.uk/elec/welder.../schematic.png

I need help figuring out the resistor values as far as wattage requirements. Also I am not sure about c1,c2,c3,c4,vr1

I think I have the rest figured out.

Tim

 

hi m8 1quater watt ress should be ok there only limmiting current to trani bases you should get components from maplins or get em off ebay. regards

 

What would c1,c2,c3,c4,VR1 be?

 

There are all labelled:

100nF
10uF
100nF
100nF
10Kohm

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

I assume 25v capacitors?

What exactly is the VR1? I am not sure what the VR stands for.

 

As long as they are higher than the supply it's fine.

Variable Resistor, a poteniometer, or a preset resistor, depending if you want it adjustable or preset.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

Thanks..I have pretty much all of the components figured out now.

Now the second part I need help with is undertanding all of Vin,grounds etc. I would figure you just need pos/neg but then again I am probably just not smart enough to undertsand this schematic fully. Can anyone give me a dumbed down version of this schematic..maybe a pop-up book =) Seriously, I really would like to build one of these but I dont want to make my hair stand up on end trying to hook it all up. If someone could make up a schematic more easy to follow I would be glad to pay for it.

 

You probably are cleaver enough to understand it, you probably just don't have enough knowledge yet to understand it. Perhaps you should attempt a simpler project before you build this.

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I do not answer private messages asking for help because no one else can: benefit from advice I may give or correct me if I'm wrong.

Please ask on the open forum if you have a question and I'll be happy to help, if I know the answer.

 

I got someone off the boards to explain it to me and it makes sense now. What confused me was the multiple power connections and grounds. What I didnt realize is that it was just showing where the 2 circuits tie into eachother.

 

I redid the schematic in omnigraffle so it's a little easier to read for those interested. Let me know if there are any mistakes.

Attached Thumbnails

 

 

Very cool.. just a few things missing

IC2 is 7805 not 1805

IC1 label is missing

SCR1 label is missing..and I think it should be drawn so that the lower schematic ties directly into SCR1 and not just in the line as I know SCR1 has 3 prongs. But I could be wrong.

I think thats it.

 

Oh I see now. It's fixed. (I think - is SCR's label correct, I can't read the guy's writing?) I mistook it for a regular diode. Apparently it's silicon controlled rectifier, something I'd never heard of.

 

Can 1/6th of a Joule really weld batteries together?

These are very impressive spot welds,


Ahhh, just noticed on the link above that the author used a bank of 5 x 120,000uF capacitors. Not 120uF as shown in the diagram above. That ups the energy to 187 Joules. Far more believable.

Mike.

 

Sorry about that, fixed now.

 

SCR1 is hard to read its actually 50R1A20. Here is a link to one
http://www.irf.com/product-info/data...data/50ria.pdf

I have attached my parts list so far. I had to convert my excel file to .txt so its a little hard to read.

Attached Files

Welder-parts.txt (1.3 KB, 12 views)