Home built TIG footpedal: need 14 pin wiring
 

I've built a foot pedal with a pot and a switch. It's for a Thermal Arc
250 GTSW which has a 14 pin connector. I've measured the voltages on the
connector and found more wires than expected.
Can someone tell me what the pins are used for. I would like to know what
all the pins do, even the ones I don't need for the foot pedal, if anyone
knows, as I plan to build a pulser for it latter.
I've called Thermal Dynamics twice and they said they would send me the
manual but so far nothing has arrived.
Here is what I measured with my VOM:
Pin Reading
A 25.9 VAC
B 0 V
C 0V
D 0V ( Approx 0 Ohms to ground )
E 0V
F Not connected
G 0V ( Approx 0 Ohms to ground )
H 42.9 VAC
I Not Connected
J Not Connected
K Not Connected
L 120 VAC
M 5.1 VAC
N 4.3 VAC
I was surprised to find no DC voltages.

Thanks for any help you can give
Jack

Home built TIG footpedal: need 14 pin wiring
 

Jack Z wrote:

I've built a foot pedal with a pot and a switch. It's for a Thermal Arc
250 GTSW which has a 14 pin connector. I've measured the voltages on the
connector and found more wires than expected.
Can someone tell me what the pins are used for. I would like to know what
all the pins do, even the ones I don't need for the foot pedal, if anyone
knows, as I plan to build a pulser for it latter.
I've called Thermal Dynamics twice and they said they would send me the
manual but so far nothing has arrived.
Here is what I measured with my VOM:
Pin Reading
A 25.9 VAC
B 0 V
C 0V
D 0V ( Approx 0 Ohms to ground )
E 0V
F Not connected
G 0V ( Approx 0 Ohms to ground )
H 42.9 VAC
I Not Connected
J Not Connected
K Not Connected
L 120 VAC
M 5.1 VAC
N 4.3 VAC
I was surprised to find no DC voltages.


did you try measuring BETWEEN the pins, rather than relative to the
machine's
case (or the work clamp)? I am guessing the internal logic is floating, or
possibly "grounded" to some particular terminal inside the welder.

Jon

Home built TIG footpedal: need 14 pin wiring
 

I was surprised to find no DC voltages.

There may not be a DC voltage for the pot if the switch isn't made. I don't
know anything about your welder but I was curious enough to do a bit of
research. I couldn't find your specific model on their site and nearly
every similar model uses an 8-pin connector but I did find one model that
uses a 14. You can see the pinout for it on page 72 at:

http://www.thermadyne.com/tai/litera...430429_490.pdf

It seems to agree with your list for the most part but where you show 120VAC
on pin L it says it's not used.

Hope it helps!

Best Regards,
Keith Marshall


"Even if you are on the right track, you'll
get run over if you just sit there."
- Will Rogers (1879-1935).


"Jack Z" wrote in message
news:ZpmCc.3996$X36.1950@fed1read05...
I've built a foot pedal with a pot and a switch. It's for a Thermal Arc
250 GTSW which has a 14 pin connector. I've measured the voltages on the
connector and found more wires than expected.
Can someone tell me what the pins are used for. I would like to know
what
all the pins do, even the ones I don't need for the foot pedal, if anyone
knows, as I plan to build a pulser for it latter.
I've called Thermal Dynamics twice and they said they would send me the
manual but so far nothing has arrived.
Here is what I measured with my VOM:
Pin Reading
A 25.9 VAC
B 0 V
C 0V
D 0V ( Approx 0 Ohms to ground )
E 0V
F Not connected
G 0V ( Approx 0 Ohms to ground )
H 42.9 VAC
I Not Connected
J Not Connected
K Not Connected
L 120 VAC
M 5.1 VAC
N 4.3 VAC
I was surprised to find no DC voltages.

Thanks for any help you can give
Jack