Lincoln Amptrol on the cheap.

Count me among those who think that $150 (or more) for a potentiometer, a switch, some wire, and an Amphenol connector is absurd. I've looked back through the archives and see that that for Lincoln this is a 10 K pot. I'm looking at the excreable excuse for a wiring diagram included with my manual (Ranger 250, K1725-1 - the first version of the Ranger

250) and I'm making the following guesses - I don't see the detailed information in the older posts I've looked at. This is a 6-pin Amphenol connector, pins ABCDEF:

ABC are grouped as remote control, I'm guessing one end of potentiometer, wiper, other end of potentiometer, respectively.

DE are grouped as contactor, I'm guessing closing the switch turns welding on, opening it turns welding off, and that it need not be a hefty switch.

F is ground, seems obvious.

I'd just like to verify that "what I'm guessing" matches up with what other folks have done before I screw anything up by assuming I guessed right. I also don't find a complete consensus in the old posts regarding linear versus log (aka audio) pots for these controls. Even if I'm guessing correctly, it would be nice to know ahead of time whether wiper B at the A end of the pot is high amps or low amps.

I do stick welding with the machine. Eventually I'll probably get a TIG torch, as it has a TIG mode, though it is DC-only and lift-start (how will this limit what can be done?)

MIG with Lincoln accessories is another case of highway robbery, AFAICT, but a Readywelder seems possible eventually, given the presence of a CV mode.

The remote control would be useful now, as I have 50 foot (00) cables on it, and no wheels on it at present.

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The 6 pin amphenol is as you stated. A, B, & C are for the 10K ohm remote control pot. I understand that a non-linear pot is used in a TIG foot pedal. Pin B is the pot wiper. I am almost positive that jumping A to B will produce full output.

Pins D & E are connected together to turn on the output. You are right, probably not much current here. I believe this only signals the control PC board to begin sending gate signals to the chopper. There is no large contactor coil being driven by this connection.

I hope this helps. Bob

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Wayne Harris

Can this type of setup be used to power an electric blower on my coal forge? I have an electric blower (I'm looking for a hand-cranked model) that just gets my forge fire way too hot even using a damper.

I've thought about wiring a dimmer switch or something to it, but thought the foot control thing might work too.


Reply to
Rick Barter

Wall dimmer switches work fine for small induction motor blowers, just get one with a high wattage capacity.

Reply to
Ernie Leimkuhler

The amptrol used on welders just signals the electronics in the welder what to do. It doesn't handle any power. Since your blower motor doesn't have the necessary electronics, what they're talking about won't work for you.

If the blower motor is a series wound, brush type, universal motor, then a lamp dimmer would work as a speed control. But it probably isn't. It is probably some type of induction motor, and motor speed is fixed by the power line frequency and the number of poles the motor has.

You *should* be able to fix an effective damper over the inlet to the blower to control blast. I just use a flat piece of sheetmetal fixed to the blower by a single screw near one end. By pivoting it so that more and more of the inlet is covered, I get less and less blast. Putting a damper on the outlet side of a blower doesn't work nearly as well, and can damage the motor (loads up the blower causing the motor to pull too much current).


Reply to
Gary Coffman

Thanks for the info Gary and Ernie. It's appreciated. I have more questions and other things to bring up that really don't fit in this group. I'm going to move my questions and stuff over to alt.crafts.blacksmithing where they belong.


Reply to
Rick Barter

Page 28 of the manual for the Lincoln Idealarc TIG 250/250 shows a schematic of the Amptrol:

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You have to blow it up to about 800% to see it very well but it's better than nothing. It shows the pinout and best I can tell it shows a 5K pot instead of 10K.

Pages 26 and 27 show it better but they don't show the size of the pot. Page 24 shows a parts breakdown of the Amptrol but no pot size.

Best Regards, Keith Marshall

"I'm not grown up enough to be so old!"

Reply to
Keith Marshall

Aha. The online PDF manual for the current version of the Ranger 250 has a much better schematic, and while it may not match my welder in all details, it does (at 600%) clearly show both the output control pot (10K) and it's direction of operation. Since the wire numbers for that are related to the wire numbers at the remote control inputs, this does clarify things. This is good.

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