How to find a replacement for massage chair transformer STL0219000 (110v to 24v)

[Kkwcheng]

Hi,
I’m new here so nice to meet you all. I have hit a dead end in my research for a replacement transformer; existing one is broken (charred and blackened). I can’t find the massage chair manual online to determine the specs of the broken transformer (amps, etc). i was able to find an old old post from someone that have the same issue as me (needing a replacement). Can anyone here help me figure out the specs of this transformer or point me in a direction to a store or website where I can look for a replacement Transformer.

massage chair model: King Kong Deluxe Air Massage model 5562.
Here are pictures of the transformer I need.

Thank you in advance.

 

[Diver300]

An exact replacement will be hard to find. However, you may be able to find something that will replace it, even if it looks different.

The primary winding is the lower winding, the one nearer to the fixing holes. There seems to be a thermal fuse in that winding, which is probably all that has gone wrong. Transformers don't wear out. They generally only fail if they overheat, and that one hasn't been overheated, because it doesn't look burned. Do you know what caused it to fail?

It seems that there are a total of 6 wires connected to the secondary. That makes me think that the output is no just one or two 24 V windings, or a 24 V winding with a centre connection, so 12 - 0 - 12. I think that there may be other output voltages. If you do replace the transformer, it may be possible to replace it with more than one transformer, one for the 24 V, and one for the other voltages.

Can you find where the wires go to?

 

[ronsimpson]

Why do you think the transformer is dead? (I know ... no power) Have you looked for a fuse?

 

[Nigel Goodwin]

Why do you think the transformer is dead? (I know ... no power) Have you looked for a fuse?

Generally there's a non-replaceable heat fuse inside the transformer.

 

[sagor1]

You can often buy replacement thermal fuses. The trick is to carefully open up the wrapping tape where the primary comes into the transformer, and look for a small square shaped thermal fuse. Some may be different shapes. They are rated for temperature (for example 130C) and a maximum current (ie: 2A). Either of those conditions, if exceeded, causes the fuse to pop. However, I've seen them just weakened due to age (15 years) in one case of my own.

 

[Nigel Goodwin]

You can often buy replacement thermal fuses. The trick is to carefully open up the wrapping tape where the primary comes into the transformer, and look for a small square shaped thermal fuse. Some may be different shapes. They are rated for temperature (for example 130C) and a maximum current (ie: 2A). Either of those conditions, if exceeded, causes the fuse to pop. However, I've seen them just weakened due to age (15 years) in one case of my own.

That's OK if the fuse is on the outside, but often it's on the inside of the winding

 

[Kkwcheng]

An exact replacement will be hard to find. However, you may be able to find something that will replace it, even if it looks different.

The primary winding is the lower winding, the one nearer to the fixing holes. There seems to be a thermal fuse in that winding, which is probably all that has gone wrong. Transformers don't wear out. They generally only fail if they overheat, and that one hasn't been overheated, because it doesn't look burned. Do you know what caused it to fail?

It seems that there are a total of 6 wires connected to the secondary. That makes me think that the output is no just one or two 24 V windings, or a 24 V winding with a centre connection, so 12 - 0 - 12. I think that there may be other output voltages. If you do replace the transformer, it may be possible to replace it with more than one transformer, one for the 24 V, and one for the other voltages.

Can you find where the wires go to?

The wires go to the circuit board that the transformer is attached to at various locations. Some wires also comes from the power cord (110V).
I believe I need to figure out the amperage of this transformer to find a similar replacement transformer. I already know its 110V, 24V based on the label.
If the power cord is 110V and there is a fuse at the power cord box rated for 5amp/250V, then the POWER (P=IV) is 550 Watts. Since through the transformer, power is conserved, then the 550 Watt at 24 volts results in an "implied" current of (550Watts/24V = 22 amps). This seems to imply that the transformer is 22 amps which seems high?!? Or maybe that is correct given this is a massage chair with motors and gears? Any insight here is appreciated.

 

[Kkwcheng]

Why do you think the transformer is dead? (I know ... no power) Have you looked for a fuse?

Short answer: the transformer had smoke come out and blackened/slightly charred.

Longer answer: I had tested with a RMS voltmeter by removing the wire connections one by one to check for continuity. When I got to this transformer it didn't work. I then tried to put everything back so my 18 month old baby won't get too adventurous and fiddle with the electronics. After I put everything back I decided to plug it in one more time for the heck of it and immediately I heard a cracking noise and smoke. I opened it and now the transformer is smoking and blackened.

 

[Kkwcheng]

You can often buy replacement thermal fuses. The trick is to carefully open up the wrapping tape where the primary comes into the transformer, and look for a small square shaped thermal fuse. Some may be different shapes. They are rated for temperature (for example 130C) and a maximum current (ie: 2A). Either of those conditions, if exceeded, causes the fuse to pop. However, I've seen them just weakened due to age (15 years) in one case of my own.

I read about this in another forum which seem like something I could have attempted but after the smoking/charred incident I can see that the transformer is fried. This massage chair is 10-15 years old.

 

[Kkwcheng]

You can often buy replacement thermal fuses. The trick is to carefully open up the wrapping tape where the primary comes into the transformer, and look for a small square shaped thermal fuse. Some may be different shapes. They are rated for temperature (for example 130C) and a maximum current (ie: 2A). Either of those conditions, if exceeded, causes the fuse to pop. However, I've seen them just weakened due to age (15 years) in one case of my own.

I read about this in another forum which seem like something I could have attempted but after the smoking/charred incident I can see that the transformer is fried. This massage chair is 10-15 years old.

 

[sagor1]

Well, since the transformer "smoked", not much you can do now. Odds are very slim you will find a proper replacement. Without knowing the secondary voltages from the transformer, you will have to replace the entire unit, if the vendor supplies it.

 

[Pommie]

The wires go to the circuit board that the transformer is attached to at various locations. Some wires also comes from the power cord (110V).
I believe I need to figure out the amperage of this transformer to find a similar replacement transformer. I already know its 110V, 24V based on the label.
If the power cord is 110V and there is a fuse at the power cord box rated for 5amp/250V, then the POWER (P=IV) is 550 Watts. Since through the transformer, power is conserved, then the 550 Watt at 24 volts results in an "implied" current of (550Watts/24V = 22 amps). This seems to imply that the transformer is 22 amps which seems high?!? Or maybe that is correct given this is a massage chair with motors and gears? Any insight here is appreciated.

The fuse is there to protect things and is no indication of the power taken.
A better indicator of the wattage of the transformer is it's size. A similar sized transformer will have a similar power rating.

Mike.

 

[Kkwcheng]

Well, since the transformer "smoked", not much you can do now. Odds are very slim you will find a proper replacement. Without knowing the secondary voltages from the transformer, you will have to replace the entire unit, if the vendor supplies it.

This company went out of business so my emails and phone calls went no where. I think I'll try to find a similar replacement unit by estimating the size of the transformer. Thanks!

 

[Kkwcheng]

The fuse is there to protect things and is no indication of the power taken.
A better indicator of the wattage of the transformer is it's size. A similar sized transformer will have a similar power rating.

Mike.

Got it, I'll give that a try; estimate the size of the transformer.

 

[Diver300]

Short answer: the transformer had smoke come out and blackened/slightly charred.

Longer answer: I had tested with a RMS voltmeter by removing the wire connections one by one to check for continuity. When I got to this transformer it didn't work. I then tried to put everything back so my 18 month old baby won't get too adventurous and fiddle with the electronics. After I put everything back I decided to plug it in one more time for the heck of it and immediately I heard a cracking noise and smoke. I opened it and now the transformer is smoking and blackened.

The photos didn't show any smoke damage or darkened windings, which is why I asked.

It sounds like you may have reconnected something wrong.

 

[Kkwcheng]

The photos didn't show any smoke damage or darkened windings, which is why I asked.

It sounds like you may have reconnected something wrong.

Yeah it is definitely a possibility. I tried taking pictures before I took it apart but I did have a couple of pictures at the wrong angle . Now it sounds like my next steps are to try to estimate the transformer size to guess the Wattage to find a similar transformer replacement. Then I get to figure out how I should mount the new transformer since I doubt I’ll be so lucky that the mounting holes match up haha. Actually i might just try to bring the broken transformer into a store or something to see if someone can help me identify/estimate the size. Too bad a lot of brick and mortar stores are closed down these days.

 

[JimB]

There is a calculation which will give a good estimate of the VA rating of a transformer.

If you can post the dimensions of the core of the transformer, I will have a go at calculating for you, once I find the formula, it is near by somewhere.

JimB

 

[Nigel Goodwin]

There are also far too many wires there - a plain 110v/24V transformer would only have 4 wires, 2 in and 2 out.

So you need to work out what the other wires are, presumably multiple windings or taps. Follow all the wires and see where they go.

The VA rating isn't that much bother, essentially (and crudely) you just need one of a similar size and weight - or a little bigger and heavier for greater safety margin.

 

[Kkwcheng]

There is a calculation which will give a good estimate of the VA rating of a transformer.

If you can post the dimensions of the core of the transformer, I will have a go at calculating for you, once I find the formula, it is near by somewhere.

JimB

Hi JimB, it took me a while to get toy this so hopefully you can still help. Really appreciate this.
please see attached pictures for the dimensions of this broken transformer. Would be great to get an estimate the VA rating of this transformer.

 

[Nigel Goodwin]

Just look up transformers on any component suppliers website - there's nothing 'magic' about different ones, a similar size is likely to be a similar rating, within fairly close tolerances.

You can even filter by sizes, for example RS Components give 50VA and 75VA transformers if you enter 79mm x 65mm - with the 75VA ones been the much 'chunkier' squarer shape ones. So 50VA looks about right.