Weller help

[Steve]

Hi,

My trusty weller iron failed me today.

Looking at the iron, there's no model number written on it. I've posted a picture, can anyone help identify the model so I can obtain a replacement element? Measuring the element's resistance, it's up in the megohms.

The PSU has a digital LED display with a rotary knob to set the temperature. The output socket says "EC1201 only" but googling for pictures of an EC1201, it looks like a later iron.

Thanks,

Steve.

[Radio Wrangler]

I don't know my way round the later variable temperature ones, but it looks to be a simple derivative of the TCP1 family. You've got the light blue later handle and what I suspect is the same heater element.

What's different is a temperature sensor running down the centre bore of the heater, just where the magnetic temperature switch used to go, pressed by a spring against the back face of the bit.

I wouldn't be surprised if it is still the same 24v 48W element they've always used.

David

[G0HZU_JMR]

I think you may have a Weller iron that is vaguely related to one I was given recently. Mine looks like the old school TCP series iron but it is actually something different. Mine is designed to work with the later micro controlled bases like the one you describe.

It runs with tips that look very like the classic TCP series but they are not the same. They look the same as a TCP tip except the tip is hollow. i.e. if the tip was a 'bullet' then the back of the bullet where the firing pin strikes is hollow and not solid like the classic old school TCP tips.

The iron I have here has FE50 engraved on the round metal plate with the three screws that hold it to the plastic body of the handle. It was given to me as a non runner because the owner couldn't get it to work with the WSD81 base.But I managed to get it to run by turning off the sleep function in the WSD81 base unit.

My iron handle is black and has the option of the fume extraction pipe but the guts inside may be similar to yours? I think the FE part of FE50 refers to the Fume Extraction.

If you google for Weller FE50 you can find all kinds of info including internal images and parts lists etc. It might have the same guts inside?

Note:
I just realised that the FE50 element is offset slightly from centre because of the need to accommodate the FE pipe. So you probably won't be able to use the FE50 element.

[Steve]

Hi David,

Thanks for the reply.

My picture could be clearer. The temperature sensor is separate from the heating element.

Enclosed is a clearer picture of the element.

Thanks,

Steve.

[AuroraB]

Looks like an iron from the ECP series.... the PSU should have label
Picture?

[Alistair D]

Steve, your picture is actually the temperature sensor not the element. On that basis which part is open circuit? The element resistance should be somewhere between 10 to 20 ohms assuming the supply voltage to the element is 24 volts.

Al

[Radio Wrangler]

Yeah, that's the sensor.

The element is tubular, the sensor fits down the middle of it, and the sleeve which retains the bit fits around it and its nut screws onto the threads at the cold end of the element.

The black thermoset plastic box on the sensor is a replica of the switch housing of the original TCP. I think you may just need a plain old TCP heater. Weller have left a lot of parts untouched.

David

[Steve]

Ah-ha, thank you gentleman. That all makes much more sense now!

OK, the element is fine - it registers 14 ohms cold. Running it on the bench PSU proves it is still working.

The PSU unit is a EC2100D. The heater supply is controlled via a triac. With the heating element disconnected I register 28VAC on the triac output. With the heater connected, the triac output drops to virtual nil, with the input still sitting at 28VAC.

I'm guessing the triac is U/S?

Steve.

[Radio Wrangler]

Either the triac or whatever controls it.

David

[Alistair D]

The 28 volts could just be a small amount of leakage current.

You mentioned earlier that the temp sensor read in the megaohms region. It may still be that that is faulty. I do not know what the correct range of resistance of this device. One thing that may be worth a try is to substitute a variable resistor for the sensor and adjusting the resistance to see if there is a value that will turn the heater on.

Al

[Steve]

Thanks everyone.

Yes, the voltage I was seeing appears to be just leakage. I'd assumed (wrongly) that the low temperature reading it was displaying would cause the iron to operate.

Strapping a resistor across the temperature sensor input to generate a reasonable reading and then adjusting the temperature setting to a higher value, results in the heater coming on. The output voltage varying dependant on the temperature setting.

So the temperature sensor appears to have gone open circuit.

Now to find a replacement.

Thanks again.

Steve.

[Steve]

Just to complete this thread for anyone needing to replace a heating element in such an iron. I can confirm the heating element is a standard TCP 45W 24V item.

[Top Cap]

I have a couple of HE TCP elements spare if anyone is desperate. Also a couple of the old style magnetic operated switches, all NOS.

[Julesomega]

The temp sensor is most likely the standard type thermocouple (K type?) and should read zero ohms. Maybe you can graft one in, otherwise it looks likely the Antex TC50 iron which I use here (24V 50W) would work with your control unit, though you'd need to confirm / change the DIN plug connections
Replacement Antex irons are available from Antex, but I guess you've priced up a Weller replacement by now
- Julian

[Steve]

Hi Julian,

A replacement sensor works out around £40 inc. postage. So I'm holding off buying one just yet in the hope a cheaper alternative comes along. I've also got a metcal iron, so I'm not completely without soldering facilities.

I will see if I can get the actual thermocouple out of the sensor, that could be a much cheaper solution.

Thanks,

Steve.

[Alistair D]

To confirm that the sensor is a thermocouple we need Steve to confirm what value of resistor got the iron heating and what temperature the display read. A thermocouple will have a very low resistance of say an ohm or two.

Al

[Julesomega]

The control unit will not actually be measuring resistance, it takes the voltage from the T/C which I think will be of the order of 10mV when soldering-hot. I hope you can find a replacement at little cost: Maplin ref. N38CB looks similar but has a handle and connector that you won't need

[PETERg0rsq]

The Weller EC1201 iron uses a Platinum RTD sensor, which is also known as a "resistance thermometer".

Therefore a thermo-couple will be totaly unsuitable!

I guess the only replacement option is a Weller sensor!

The irons can sometimes be found on that well known internet auction site for about £15 to £30 depending on the day! (there is one up there at the moment)

Peter

[Steve]

I can confirm a K type thermocouple doesn't work.

I've found that substituting a 33 ohm resistor generated a reading of around 160 degrees C.

I now have a brand new replacement iron. Not particularly cheap but it gives me a spare heater, cable, etc. as well.

Thanks everyone.