Zero crossing detection for a battery spot welding machine with what parts should be used
sam_sam_sam
Posts: 2,286
I have two questions about this
What micro controller would you use and why
Are there any code examples for this type of application for the micro controller you are suggesting
Here is basically what I would like to be able to with this knowledge
I would like to control a battery welding transformer at low to high amperage output on the secondary winding circuit ( I just need a code example for this particular part )
I would also like to be able to control the amount of time the transformer has power to the primary coil
Depending on which micro controller you tell me I would have some experience doing this part maybe ?
Because the micro controller that controls battery welding machines are Smile because you will be lucky if they will last a year with minimum use
The most common failure of these units are as follows
No function control to trigger the transformer output but the controller power on and boots up
Or
It sometimes trigger the transformer output but unpredictable weather it works or not
Or
Does not power on and dose not boot up but has power to the micro controller
Or
The controller power on but controller screen is blank or is scrambled and can not make sense of what is on the screen
Or
The functionality of them are not concise enough to be reliable and your welds suffer from this issue so you have to keep redoing them until get good results ( will lead to controller failure eventually )
The only thing that is not a real big deal is the cost of these controller boards are not very expensive less than $40.00 for a controller that has a lot features on it
Less for controllers that have less features on it
But they all have the same problem that they do not last long
So I am getting to point that I am looking into building one of them and see if it would last longer
This is because I saw this post that got me to ask these questions about how this might be done
What micro controller would you use and why
Are there any code examples for this type of application for the micro controller you are suggesting
Here is basically what I would like to be able to with this knowledge
I would like to control a battery welding transformer at low to high amperage output on the secondary winding circuit ( I just need a code example for this particular part )
I would also like to be able to control the amount of time the transformer has power to the primary coil
Depending on which micro controller you tell me I would have some experience doing this part maybe ?
Because the micro controller that controls battery welding machines are Smile because you will be lucky if they will last a year with minimum use
The most common failure of these units are as follows
No function control to trigger the transformer output but the controller power on and boots up
Or
It sometimes trigger the transformer output but unpredictable weather it works or not
Or
Does not power on and dose not boot up but has power to the micro controller
Or
The controller power on but controller screen is blank or is scrambled and can not make sense of what is on the screen
Or
The functionality of them are not concise enough to be reliable and your welds suffer from this issue so you have to keep redoing them until get good results ( will lead to controller failure eventually )
The only thing that is not a real big deal is the cost of these controller boards are not very expensive less than $40.00 for a controller that has a lot features on it
Less for controllers that have less features on it
But they all have the same problem that they do not last long
So I am getting to point that I am looking into building one of them and see if it would last longer
This is because I saw this post that got me to ask these questions about how this might be done
Comments
Drawings, diagrams, schematics, photos, links. Number 5 needs more input. More input! More input! The more, the better.
btw, I doubt that the microcontroller is cr** but the overall design might not take into account the large amounts of EM energy being induced throughout the circuit. If it is built to a price then that will compromise the design. The actual micro used is not really relevant although it should be a single-chip with Flash and preferably internal runtime oscillator (not just for booting). The smaller the chip the better IMO and those like the EFM8 parts I use certainly fit the bill but then again, another might be more suitable etc.
What Peter posted!
Energize time is essential a fairly simple timing pulse problem, but keep in mind the Welder curves often include :
* Welder Current
* Welder Voltage
* Welding pressure
* Welding displacement
and those all need fast analog measurements.
and you may need to decide if AC fractional cycle control is needed, or if DC (lower ripple current) is needed.
You could also choose primary side (eg triac/SCR) or secondary side (MOSFET) controls.
Welders have larger energies around, so reliable design needs special care & a watchdog is probably a good idea.
How does production test the welds?
At one company I worked for, production would place the welded parts in a torque tester, and at another they pull tested 5 samples before running.
I have more or less have decided to do something like this that in figure number 3 and 4
And use some of the code that is below
https://forums.parallax.com/discussion/76898/controlling-120-vac-lights-with-a-stamp
I need to get all the parts together and get it to work