Questions about Arduino spot welder controller

Read the article of the DIY battery tab resistance fine-spot welder here: http://www.avdweb.nl/tech-tips/spot-welder.html

Because the electronics and software is too complicated for many people I have made a printed circuit board.

http://www.avdweb.nl/arduino/hardware-interfacing/spot-welder-controller.html

Questions about the spot welder controller can be asked in this topic.

Interesting. Just been looking over the software Here

Just wondering what this bit is supposed to be doing.

#include 
#include  // library
#include  // library
#include  // library

I don't quite understand why you are shorting the two big wires from the transformer. Isn't one end supposed to go to the ground clamp?

KenF: Interesting. Just been looking over the software Here

Just wondering what this bit is supposed to be doing.

#include 
#include  // library
#include  // library
#include  // library

Yes that is weird, long story, but fixed now.

330R: I don't quite understand why you are shorting the two big wires from the transformer. Isn't one end supposed to go to the ground clamp?

It is not shorted.

That's an unusual arrangement. Usually the two arms are diametrically opposed, either vertically or horizontally, so that they can compress the work parts together before sending the current through them. I can't see how your welder would work without pinching the two work parts together. See http://www.tool-net.co.uk/p-363291/clarke-csw6t.html?gclid=CNauroS6zMMCFU7KtAodBjgAHQ for an example.

Henry_Best: That's an unusual arrangement. Usually the two arms are diametrically opposed, either vertically or horizontally, so that they can compress the work parts together before sending the current through them. I can't see how your welder would work without pinching the two work parts together. See http://www.tool-net.co.uk/p-363291/clarke-csw6t.html?gclid=CNauroS6zMMCFU7KtAodBjgAHQ for an example.

This electrode arrangment is used for battery tabs welding or other welding tasks, where the access is limited to one side only. Search for battery tab welding and you 'll see why is this done like this.

Hello Albert!
My name is David and I was curious where i can find the <Switch.h> library and the <Albert.h> library.
I found the <Streaming.h> library and I am assuming that the <Arduino.h> library is already installed with my Arduino software program I recently installed on my laptop. Thank you in advance for your help!!
P.S. I think your spot welder is awsome!!! Kudos & Accolades!!!

interesting. what is the typical amp load and what thickness of metals can this handle ?

I have wanted to weld battery tabs, but since it is so rare, just buy them pre-welded.

also wanted to make/weld thermocouples from raw thermocouple wire.

can't wait for the youtube on this.

KenF: Interesting. Just been looking over the software Here

Just wondering what this bit is supposed to be doing.

#include 
#include  // library
#include  // library
#include  // library

This has been changed now

include

include // library

include // library

include // library

KenF: Interesting. Just been looking over the software Here

Just wondering what this bit is supposed to be doing.

#include 
#include  // library
#include  // library
#include  // library

This has been changed now

include

include // library

include // library

include // library

Henry_Best: That's an unusual arrangement. Usually the two arms are diametrically opposed, either vertically or horizontally, so that they can compress the work parts together before sending the current through them. I can't see how your welder would work without pinching the two work parts together. See http://www.tool-net.co.uk/p-363291/clarke-csw6t.html?gclid=CNauroS6zMMCFU7KtAodBjgAHQ for an example.

You can see here the Spot welder opposed configuration The series configuration spot welding is not very common, but always used for welding batteries.

dwforbes: Hello Albert! My name is David and I was curious where i can find the library and the library. I found the library and I am assuming that the library is already installed with my Arduino software program I recently installed on my laptop. Thank you in advance for your help!! P.S. I think your spot welder is awsome!!!! Kudos & Accolades!!!

Look here: http://www.avdweb.nl/arduino/troubleshooting.html

dave-in-nj: interesting. what is the typical amp load and what thickness of metals can this handle ?

I have wanted to weld battery tabs, but since it is so rare, just buy them pre-welded.

also wanted to make/weld thermocouples from raw thermocouple wire.

can't wait for the youtube on this.

See here: http://www.avdweb.nl/tech-tips/spot-welder.html#h7-maximum-welding-thickness

I mounted the electronics for the spot welder, I turned, but I always 220 V on output to the transformer. I checked and installed all components correctly.It has already happened a problem like this? Thanks.

Kingmaury: I mounted the electronics for the spot welder, I turned, but I always 220 V on output to the transformer. I checked and installed all components correctly.It has already happened a problem like this? Thanks.

If you want to measure the output voltage, use a load.

Kingmaury: I mounted the electronics for the spot welder, I turned, but I always 220 V on output to the transformer. I checked and installed all components correctly.It has already happened a problem like this? Thanks.

You must load the output with a MOT, lamp, resistor etc.

Considering that each one of the two SCRs switch on for either the positive or negative mains half-waves which are 10ms long (assuming 50 Hz for the power mains) is there any reason why the minimum welding time cannot be set to 10 ms instead of 50 ms?

Maybe with a shorter welding time there will be no need for switching to the lower 400A current mode.

candido: Considering that each one of the two SCRs switch on for either the positive or negative mains half-waves which are 10ms long (assuming 50 Hz for the power mains) is there any reason why the minimum welding time cannot be set to 10 ms instead of 50 ms?

Maybe with a shorter welding time there will be no need for switching to the lower 400A current mode.

The first weld controller that I have built had no synchronisation and therefore the weld time was not very accurate (+/-20ms) and the minimum weld time was set to 50ms because of reproducibility. For me this was fine. But with the synchronisation, the weld time is more accurate and a shorter weld time is possible, but I have not tested this. The weld times can be changed in the software easily.

Maybe with a shorter welding time there will be no need for switching to the lower 400A current mode. I think that very short weld times are tricky, in some circumstances it may work, it should further be examined.

avandalen: The first weld controller that I have built had no synchronisation and therefore the weld time was not very accurate (+/-20ms) and the minimum weld time was set to 50ms because of reproducibility. For me this was fine. But with the synchronisation, the weld time is more accurate and a shorter weld time is possible, but I have not tested this. The weld times can be changed in the software easily.

Maybe with a shorter welding time there will be no need for switching to the lower 400A current mode. I think that very short weld times are tricky, in some circumstances it may work, it should further be examined.

OK, that makes sense, thanks.

Some capacitor discharge spot welders can use dual pulses where the first is a short pulse in the order of 10 ms and the second (after, say, a 10 ms pause) is a bit longer. It was in this context that I had asked the initial question.

As you say, this will require some investigation and testing. In theory the current from the capacitor discharge will be a decreasing exponential while the one from the transformer should be sinusoidal. These different waveforms will probably produce different welds.