Hi Everyone,

I'm trying to fix a LED on a T-fal garment steamer. I recently purchased a used unit (different model) for parts to fix my original steamer, which works perfectly fine now. Now I'm trying to fix the second unit. The only difference between these two models is the original unit had a circuit board to control a wireless switch on the steamer handle. It was too complicated to fix so I used the internal wiring from the used unit and put it in the original unit. While it was open I followed the wiring and made the schematic below, but there may have been other parts like a diode hidden in wrapped wires.


On the rotary switch position 1 runs one element at 400w, position 2 runs a second element at 1100w and position three runs both at 1500w. The LED is supposed to get brighter as the power increases. Right now every time I place a new LED and power on to position 1, it stays on for few seconds and then fades out. My guess is that it's a polarity issue and a missing diode somewhere. I tried a few combinations with IN4007 diodes but it still doesn't work.

Any suggestions?

 

Welcome. You ARE missing something - possibly a diode or 2. Your diagram as shown will power both elements in all 3 positions.

 

Hello,

A led can not be used on AC, as the reverse voltage will destroy the led.
It could be a special led with reverse voltage protection.
A standard led with a diode anti parallel should work.

Bertus

 

If the original device is indeed and LED, it is a very special one as it would have to withstand a large reverse bias.
Are you sure it wasn't a neon?

The diagram is wrong as any switch position would give full power.

 

If the original device is indeed and LED, it is a very special one as it would have to withstand a large reverse bias.
Are you sure it wasn't a neon?

The diagram is wrong as any switch position would give full power.

I'm pretty sure it's a LED. Before installing the wiring from the second unit I changed the LED with a stronger one and it works. However before the LED leads there are two wires wrapped with resistors. I slightly sliced them open to get the resistor values (68k), but there may have been a diode somewhere in that wire wrap. Maybe a small zener.

I also tried a 120v indicator light in place of the LED. It worked but all three positions on the rotary switch power run at 1500w.

I may have drawn the switch connections the wrong way. S1 and S2 are isolated. S3 connects both.

 

You're still missing something. In order for position 3 to power both elements, there has to be some form of isolation between 1 & 2. I'm beginning to suspect the heating elements are being fed by diodes and are only conducting 1/2 of the cycle. Perhaps this prevents reverse bias to the LED.

 

Hello,

In order for position 3 to power both elements, there has to be some form of isolation between 1 & 2.

Could it be that the switch has a second contact?
Something like this:

And a dual led for reverse voltage protection.

Bertus

 

That could be a possibility too. But either way, something is missing.

 

The rotary switch in most of my oil filled heaters are a kind of slide switch rotary combo.

 

@bertus

Your suggestions got me thinking I'm looking at the circuit in the wrong direction. I'm going to try something like this.

 

Again your rotary switch isn't doing anything.

 

The switch is probably something like this...



With the proper indents taking the switch past the second low position.

 

The LED works and all three switches have the correct power now. I'll do some further testing and follow up with some notes for reference.