Older Miller TIG Pedal Conversion?

Date 03-17-2007 16:50

You should probably post this on the Miller board. Most foot controls are similar using a microswitch for on/off and a varistor to control amperage. You should be able to get the owner's manual for the old pedal you have and the one for the Dynasty and compare the wiring diagrams to see the correct pin locations for the wires on the 14 pin connector. All 14 pins will not be used for the foot control, so this should be possible to do.

By MBSims

Date 03-17-2007 17:13 Edited 03-17-2007 17:15

Here's a wiring diagram for a 14-pin RFCS-14 and 6-pin RFCS-6L foot control. The wire colors and connections are the same, but the pin locations are different. If you look at the face of the connector next to the pins, you should see the pin markings (A, B, C, ...).

By rangerod (**)

Date 03-17-2007 18:45

MBSims

Thanks for the help. I will do as you advised and post on the Miller board.

Rod

By MBSims

Date 03-17-2007 22:03

I think all you need to do is order the 14-pin connector from Miller or re-use an old one and connect the wires to the correct pins. If the wires are soldered to the pins in the old connector, you should be able to remove the soldered pins from the old connector, remove the correct pins on the 14-pin connector and push the pins in their correct locations. To make an adapter, you will need a female 6-pin and male 14-pin connector plus a short piece of 5 conductor cable.

By rangerod (**)

Date 03-17-2007 22:47

Will do, Thanks.

Rod

By MBSims

Date 03-18-2007 00:12

I see from the Miller website that the Dynasty 200 uses a RFCS-14 foot control. The owners manual for the RFCS-14 shows it uses a potentiometer and not a varistor like some of the older models did. Which model of foot control do you have?

By DaveBoyer (*****)

Date 03-18-2007 03:31 Edited 03-19-2007 03:29

The resistor in the 6 pin and 14 pin units are both 1000 ohm, The older RFC-23A pedals with the 2 cables with twist lock plugs have a 15 ohm resistor.

By rangerod (**)

Date 03-21-2007 04:08

I have the varistor pedal with one cable.

By DaveBoyer (*****)

Date 03-22-2007 04:50

I am pretty sure the Dynasty will need the 1K [1000] ohm potentiometer, there are at least 2 versions of the foot pedal that use a 10K potentiometer [14E & 6L] according to the Miller manuals. If You have one of the 10K units You could probably change the potentiometer.

By billvanderhoof (****)

Date 03-21-2007 05:32

I'm confused (not unusual). My understanding of the word varistor is an avalanche device rather like two zener diodes face to face. Usually used in surge protectors and the like. I don't see how to use it in this device. Can someone point me to a diagram of one of these varistor foot pedals so I can enlighten myself.
Bill

By MBSims

Date 03-23-2007 00:24

It actually uses a wire wound resistor with a brush that slides up and down the length. I called it a varistor, but that may not be correct terminology. In any case, just changing the plug is probably not going to work for the Dynasty and may damage the new machine. Here's a link to the Miller manual:

http://www.millerwelds.com/om/o826c_mil.pdf

By billvanderhoof (****)

Date 03-23-2007 01:39

Thanks- wired like that I would have called it a potentiometer. Wired at one end and the slider I would have called it a variable resistor or a rheostat. I suppose some usage might call it a varistor but in electronics a varistor is as described above.
Bill