The temperature is regulated via a rather elegant (I think)
implementation in the iron. At the base of each tip, there's a slug
of a ferromagnetic material. The properties of this slug are
controlled during manufacture, so that it will change from a magnetic
to a nonmagnetic state at a specific temperature (e.g. 700 F).

Inside the shaft of the iron there is a switch with a magnet on the
end. When the tip is below its transition temperature, the magnet is
attracted to the ferromagnetic slug on the back of the tip, the switch
is pulled forwards, the contacts close, and current flows through the
iron's heating coils. When the tip reaches its desired temperature
the ferromagnetic slug becomes non-magnetic, the magnet in the shaft
"loses its grip", the switch is pulled backwards by a spring, the
contacts open, and the current to the heating coil is interrupted.
You can hear (and feel) a gentle "thick" when the magnet switch pops
back and forth.

I've heard this sort of Iron referred to as a "Curie Point" Iron. Is this
the same thing?

Bob Stephens

In article ,
Bob Stephens wrote:

I've heard this sort of Iron referred to as a "Curie Point" Iron. Is this
the same thing?

Probably so. A material's Curie point (or temperature) is the
temperature at which, when heated, the material ceases to be able to
support/retain a magnetic field, and any existing magnetic field is
randomized.

Heating a permanent magnet above its Curie temperature demagnetizes it.

The slugs used in the Weller tips have Curie temperatures of 600, 700,
or 800 degrees F (plus or minus a bit, I imagine).

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

In article ,
Bob Stephens wrote:

I've heard this sort of Iron referred to as a "Curie Point" Iron. Is this
the same thing?

Probably so. A material's Curie point (or temperature) is the
temperature at which, when heated, the material ceases to be able to
support/retain a magnetic field, and any existing magnetic field is
randomized.

Heating a permanent magnet above its Curie temperature demagnetizes it.

The slugs used in the Weller tips have Curie temperatures of 600, 700,
or 800 degrees F (plus or minus a bit, I imagine).

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

It is VERY EASY to fix / repair the Weller WTCP units.

First, Are you positive you have the CORRECT TIP in this iron.

It MUST BE A Weller "PT" style tip - other Weller model tips such as the ET
series will cause this problem and damage the iron.

Greg
w9gb


"Joshua G Senecal" wrote in message
...
Hi all,

I have a Weller WTCPS soldering station with a 201U power supply and 201P
iron, using a 700 degree F tip. Last night I powered it up in preparation
for soldering some connectors, and a few minutes later I saw that the tip
and metal shaft of the iron were glowing red-hot.

Any ideas as to what is causing this, and will it be cheap to fix? Are
there any checks I can do to diagnose the problem? Or should I just dump
the thing and buy a new one? I bought the station over 11 years ago, in
practically new condition, at a yard sale for $5, so I got my money out
of it, but if a reliable fix is cheaper than purchasing a new soldering
setup I'd rather go that route.

Thanks!

-Josh, AE6IQ

--


Remove the reversed "nospam" in the address.

It is VERY EASY to fix / repair the Weller WTCP units.

First, Are you positive you have the CORRECT TIP in this iron.

It MUST BE A Weller "PT" style tip - other Weller model tips such as the ET
series will cause this problem and damage the iron.

Greg
w9gb


"Joshua G Senecal" wrote in message
...
Hi all,

I have a Weller WTCPS soldering station with a 201U power supply and 201P
iron, using a 700 degree F tip. Last night I powered it up in preparation
for soldering some connectors, and a few minutes later I saw that the tip
and metal shaft of the iron were glowing red-hot.

Any ideas as to what is causing this, and will it be cheap to fix? Are
there any checks I can do to diagnose the problem? Or should I just dump
the thing and buy a new one? I bought the station over 11 years ago, in
practically new condition, at a yard sale for $5, so I got my money out
of it, but if a reliable fix is cheaper than purchasing a new soldering
setup I'd rather go that route.

Thanks!

-Josh, AE6IQ

--


Remove the reversed "nospam" in the address.

"Joshua G Senecal" wrote in message
...
Hi all,

I have a Weller WTCPS soldering station with a 201U power supply and 201P
iron, using a 700 degree F tip. Last night I powered it up in preparation
for soldering some connectors, and a few minutes later I saw that the tip
and metal shaft of the iron were glowing red-hot.

Any ideas as to what is causing this, and will it be cheap to fix? Are
there any checks I can do to diagnose the problem? Or should I just dump
the thing and buy a new one? I bought the station over 11 years ago, in
practically new condition, at a yard sale for $5, so I got my money out
of it, but if a reliable fix is cheaper than purchasing a new soldering
setup I'd rather go that route.

Thanks!

-Josh, AE6IQ

Josh -

Let's deal with your problem and Facts.

The WTCP series base only provides 24 volts - that's it - its a transformer
in a base.
The "brains" of the temperature control is the tip working in concert with
the SW60 switch assembly
The WTCP series has a unique click as the SW60 switch engages and
disengages - turning the heater on and off to maintain
the specific temperature engraved on the base of the removal tip.

The Red-Glow tells you 2 things:

1. The heater (Weller EC234) is still working (but you are shortening its
life operating in this manner - cherry red)
2. The WTCP series temperature control (which works with the "PT" tip and
the SW60 switch) is not working properly.

Recommend: Change tips. Improper tips will cause this problem.
Get a Weller PTA7 (which is the standard tip shipped with this iron).
The barrel net (BA-60 may also require replacement.

If iron exhibits identical problem - then the SW60 requires replacement
(shorted closed).

All parts for this specific model (WTCPS) are available from Wessco (So.
California).
Wessco also just ended a 1/2 price sale on Weller "PT" series tip in
November ($ 2.25 each)

I also have the Weller Tech Sheet for this model -- if you need
a copy. This has part numbers, diagrams and troubleshooting advice (shipped
with every unit new)

Yes, I will consider repairing for you - but it would have to be after the
holidays.
Greg
Repairing the Weller WTCP series since 1975

"Joshua G Senecal" wrote in message
...
Hi all,

I have a Weller WTCPS soldering station with a 201U power supply and 201P
iron, using a 700 degree F tip. Last night I powered it up in preparation
for soldering some connectors, and a few minutes later I saw that the tip
and metal shaft of the iron were glowing red-hot.

Any ideas as to what is causing this, and will it be cheap to fix? Are
there any checks I can do to diagnose the problem? Or should I just dump
the thing and buy a new one? I bought the station over 11 years ago, in
practically new condition, at a yard sale for $5, so I got my money out
of it, but if a reliable fix is cheaper than purchasing a new soldering
setup I'd rather go that route.

Thanks!

-Josh, AE6IQ

Josh -

Let's deal with your problem and Facts.

The WTCP series base only provides 24 volts - that's it - its a transformer
in a base.
The "brains" of the temperature control is the tip working in concert with
the SW60 switch assembly
The WTCP series has a unique click as the SW60 switch engages and
disengages - turning the heater on and off to maintain
the specific temperature engraved on the base of the removal tip.

The Red-Glow tells you 2 things:

1. The heater (Weller EC234) is still working (but you are shortening its
life operating in this manner - cherry red)
2. The WTCP series temperature control (which works with the "PT" tip and
the SW60 switch) is not working properly.

Recommend: Change tips. Improper tips will cause this problem.
Get a Weller PTA7 (which is the standard tip shipped with this iron).
The barrel net (BA-60 may also require replacement.

If iron exhibits identical problem - then the SW60 requires replacement
(shorted closed).

All parts for this specific model (WTCPS) are available from Wessco (So.
California).
Wessco also just ended a 1/2 price sale on Weller "PT" series tip in
November ($ 2.25 each)

I also have the Weller Tech Sheet for this model -- if you need
a copy. This has part numbers, diagrams and troubleshooting advice (shipped
with every unit new)

Yes, I will consider repairing for you - but it would have to be after the
holidays.
Greg
Repairing the Weller WTCP series since 1975

"G.Beat" wrote:

I also have the Weller Tech Sheet for this model -- if you need
a copy. This has part numbers, diagrams and troubleshooting advice (shipped
with every unit new)

Yes, I will consider repairing for you - but it would have to be after the
holidays.
Greg
Repairing the Weller WTCP series since 1975

I would like a copy of that, if you don't mind.

--
7 days!


Michael A. Terrell
Central Florida

"G.Beat" wrote:

I also have the Weller Tech Sheet for this model -- if you need
a copy. This has part numbers, diagrams and troubleshooting advice (shipped
with every unit new)

Yes, I will consider repairing for you - but it would have to be after the
holidays.
Greg
Repairing the Weller WTCP series since 1975

I would like a copy of that, if you don't mind.

--
7 days!


Michael A. Terrell
Central Florida

On Thu, 18 Dec 2003 11:42:58 -0500 Kalman Rubinson
wrote:

Weller sells, through distributors, replacement parts. I suggest that
you replace the temp-sensing tip element, as a start.

The only heat sensing element in the WTCP? series is the lump of metal
at the tail end of the tip. The correct tips for this iron will have a
separate bit there with a single digit stamped in it. That's normally
a 7, for 700 degrees F.

The alloy of this lump is chosen to have a Curie temp of 700F and it
will never change.

There is a magnet that runs down toward the tip and is attracted to
the tip when the tip is below its Curie point. Once the temp reaches
the Curie temp the lump no longer attracts the magnet and the magnet
is pulled back upwards by a small spring. This opens a switch in the
handle and turns off the heating element.

The usual problems with these are that something gets inside the
sleeve behind the tip and jams the magnet so it can no longer move, or
the switch contacts weld closed.

With the iron off and cold you can remove the tip retaining sleeve.
When you pull the tip out you should feel the pull of the magnet and
then feel the switch and magnet snap back into the barrel once the tip
is too far away to attract the magnet. You should repeat this to
verify that the magnet is free to move.

If you unplug the iron from the base and put an Ohmmeter on the pins
of the iron, you should see the continuity come and go as you take the
pin in and out.

Weller is owned by Cooper Tools and PDF files of replacement parts are
available on their web site.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------