Welding Tips and Tricks

Hi guys im new to the group.
Could use some advice.
I want to purchase a tig torch with a switch & potentiometer
Options are 1k 5k 10k 25k.
How do i decide which option I need.
Is the 'k' rating to do with range / sensitivity?
Or is it related to my inverter spec .
Basic 200 ac/dc tig .
Any help would be greatly appreciated.

Diegrinderman wrote: ↑Thu Jul 11, 2024 2:13 pm Hi guys im new to the group.
Could use some advice.

Hi, welcome to the group.

I want to purchase a tig torch with a switch & potentiometer
Options are 1k 5k 10k 25k.
How do i decide which option I need.

Have a look at the foot pedal that goes with your welding machine. Use the same value pot. Hopefully, it is stated in the manual (for the machine or the pedal).

Is the 'k' rating to do with range / sensitivity?
Or is it related to my inverter spec .

That is just a multiplier for the value of the pot. 10k = 10,000 ohms.

10k is pretty common.

Jack

See/Google if any info is out there as far as schematics or on pedals for your machine to be absolutely sure, but yeah.. 10K is a very common potentiometer in pedals and knobs for TIG machines.

In many cases the actual resistor value doesn't even matter that much as most machines use it as a voltage divider and just measure the position by the voltage drop across this. On these you could run pretty much any potentiometer of a few K-ohms as they will all show exactly the same voltage 'sweep' between the supply and ground across it's travel.

Usually you'd have either a 5-pin or 2 and 3-pin connectors on the machine for a pedal/knob. 3 wires will be used for the potentiometer (power, ground and 'sense') and 2 wires for the torch switch.

A few machines, but those are rare, will not use a voltage measurement but use a current measurement and here you'd need to match exactly what the machine needs/wants resistance-wise. Those will often have only a 3 or 4 pin connector.

Bye, Arno.

Arno wrote: ↑Fri Jul 12, 2024 1:10 am In many cases the actual resistor value doesn't even matter that much as most machines use it as a voltage divider and just measure the position by the voltage drop across this. On these you could run pretty much any potentiometer of a few K-ohms as they will all show exactly the same voltage 'sweep' between the supply and ground across it's travel.

Within limits, that's true. But if the resistance is too small, the calibration supply will be overloaded. If it is too large, there is more chance of picking up stray electrical noise and may be less accurate.

A few machines, but those are rare, will not use a voltage measurement but use a current measurement and here you'd need to match exactly what the machine needs/wants resistance-wise. Those will often have only a 3 or 4 pin connector.

And some are digital and don't use a resistor at all.

It depends on the machine you have and that, I don't know.

Jack