Omega Owners Forum
Chat Area => General Discussion Area => Topic started by: bigegg on 07 December 2013, 16:24:35
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I am repairing a reclining chair for a friend.
The transformer which powers the recliner motor and massage/heater is busted.
It is a standard iron cored toroidal transformer rated 12v 3A AC
Would I be able to substitute a 0-50W electronic low voltage lighting transformer?
I'm specifically looking at a YT50L from "varilight", because it is specced 0W output - if the motor, massager and heat pads are off, there is just a small LED to show power is connected -and I'm not sure what the failure mode is.
I don't know enough about electronic transformers to know if they can be used on inductive loads - or only resistive.
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I would get a proper replacement - I recently had to do one for my mother which was buzzing and did not want to mess about with circuit boards when a replacement unit complete wasn't that pricey. Is there an electrical fire risk. We had to get unit pat tested.
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Its not so much a like for like Transformer, its more to do with any DC Rectification after it thats important (could also be switch mode?), personally unless your really up on the subject, I would recommend you go down the proper Manufactures Parts route.
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proper replacement is from the states and starts at 90US$ + shipping + VAT + taxes + ???
I could just buy another iron wound transformer, and swap the plug over, but this unit I'm looking at has terminals so I can just wire it up that way - also has the advantage that it's much lighter and smaller, so can be mounted inside the chair, instead of left on the floor to be run over with a wheelchair - which is what happened to the last one.
PAT testing not relevant - private house.
When I say "transformer", "power adaptor" might be nearer - like a big wall wart, not just an electronic component.
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I would replace like with like by getting a 12v 3a toroidal transformer.
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One of these will give you 4 Amps with both windings connected in parallel.
(http://images.maplinmedia.co.uk/2x12v-208a-toroidal-transformer.jpg?w=283&h=283&r=4&o=oV3eHA6Jre71fcNv6m5tLy2qcK4j&V=WHc8)
http://www.maplin.co.uk/p/2x12v-208a-toroidal-transformer-n22jb (http://www.maplin.co.uk/p/2x12v-208a-toroidal-transformer-n22jb)
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Do you know what kind of motor is fitted? Does it want AC or DC?
If AC then the neatest solution would be an 'old school' low voltage lighting transformer with a transformer inside a case with terminals for you to connect to.
If it wants DC then you may be able to find a 12v 3A DC wall wart. Alternatively cased 12v DC switch mode power supplies are fairly easy to source.
An electronic low voltage lighting "transformer" is going to be a bit of a lottery. It could be doing something horrible to the output because 12v halogen lamps aren't going to notice.
Can you post a picture of the power supply that died?
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Can't post a pic - camera on my phone is FUBAR
it's a bog standard iron cored transformer in a plastic case - NOT toroidal, sorry, it's the sort where the iron core is made up of lots of iron laminations in the shape of an 'E'
It has four wires connected - two from the low voltage side.
two from the mains side.
no other components.
The low voltage transformer I'm looking at *is* the sort with screw terminal - I will be able to cut the wires from the old transformer, strip the ends, and connect them straight into the terminals
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You mean like this, only a 3 Amp + version?, if so then Maplins, CPC, Farnell, RS Components etc.
(http://shop.rabtron.co.za/catalog/images/tx10m012.jpg)
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Here ya go Maplins.
And if like you said your thinking of mounting inside the Chair, dont, they get warm and need ventilation. ;)
http://www.maplin.co.uk/p/12v-3a-chassis-transformer-n60jb
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IMHO - if you use anything other than one supplied by the manufacturer & for this specific model then you would contravene it's "approval" and maybe household insurance in case of fire etc.
Even worse doing it for a friend - my suggestion is get them to pay up for the "correct" replacement and keep things above board .....
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Can't post a pic - camera on my phone is FUBAR
it's a bog standard iron cored transformer in a plastic case - NOT toroidal, sorry, it's the sort where the iron core is made up of lots of iron laminations in the shape of an 'E'
It has four wires connected - two from the low voltage side.
two from the mains side.
no other components.
The low voltage transformer I'm looking at *is* the sort with screw terminal - I will be able to cut the wires from the old transformer, strip the ends, and connect them straight into the terminals
If it says "electronic" anywhere then it isn't a traditional transformer and not suitable for powering a motor.
12V 3A is only 36watts. That doesn't seem enough to power seat motors and heaters. Is it possible that the 3A is the mains input? 230V at 3A is 690W. £90 doesn't seem so unreasonable for the genuine article if that is the case.
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Yep, get a proper transformer. Many lighting transformers will be switch mode converters and unsuitable for this application. A decent quality toroidal replacement from Mapin, Farnell, RS, Rapid components, etc. will be a much better bet and they are not expensive.
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http://www.bfworkshop.com (http://www.bfworkshop.com)
I used these people - prices ok and delivery prompt.
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Can't post a pic - camera on my phone is FUBAR
it's a bog standard iron cored transformer in a plastic case - NOT toroidal, sorry, it's the sort where the iron core is made up of lots of iron laminations in the shape of an 'E'
It has four wires connected - two from the low voltage side.
two from the mains side.
no other components.
The low voltage transformer I'm looking at *is* the sort with screw terminal - I will be able to cut the wires from the old transformer, strip the ends, and connect them straight into the terminals
If it says "electronic" anywhere then it isn't a traditional transformer and not suitable for powering a motor.
12V 3A is only 36watts. That doesn't seem enough to power seat motors and heaters. Is it possible that the 3A is the mains input? 230V at 3A is 690W. £90 doesn't seem so unreasonable for the genuine article if that is the case.
definitely 3A output (actually 2917mA).
It doesn't power the seat motors - just the massage bit, possibly a heater.
I'm going to find a 3A wall wart - I think I may already have one in the shed.
Thanks for all the advice/info
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definitely 3A output (actually 2917mA).
It doesn't power the seat motors - just the massage bit, possibly a heater.
I'm going to find a 3A wall wart - I think I may already have one in the shed.
Thanks for all the advice/info
I am repairing a reclining chair for a friend.
The transformer which powers the recliner motor and massage/heater is busted.
It is a standard iron cored toroidal transformer rated 12v 3A AC
Let us know when you find out what it actually does provide power to.
Even if it doesn't drive any big motors I can't see how the massage function can work without a motor?
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yeaH, :-[ oops.
The massage unit is built into the seat upper, and is innaccesible without stripping out the upholstery, so I don't know how it actually works - I've never seen it work, but I agree - must be a motor.
It's on a seperate remote control which controls the heater and massage unit - neither of which work without the power supply which I'm trying to replace.
The recliner function is on a seperate power supply, and control - and works perfectly.
I've been in my shed, and I've only got a 2A wall wart, so going to browse the catalogs tomorrow to find a 3A
Thanks for all the help - even with me giving the wrong info :-[
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Just for my own information.
can someone please just confirm:
"electronic" transformers such as used for low voltage lighting can only be used for resistive loads, and are not suitable for inductive loads, such as motors?
as a side issue - since I'm converting my MV6 interior to a 3 piece suite - can a PC power supply be used to power motors?
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Just for my own information.
can someone please just confirm:
"electronic" transformers such as used for low voltage lighting can only be used for resistive loads, and are not suitable for inductive loads, such as motors?
as a side issue - since I'm converting my MV6 interior to a 3 piece suite - can a PC power supply be used to power motors?
Probably not due to the high peak current on a motors start up. Where motors are an inductive load, you need to correct the power factor using a suitable sized capacitor. This will also help smooth out peak current for short peak loads.
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"electronic" transformers such as used for low voltage lighting can only be used for resistive loads, and are not suitable for inductive loads, such as motors?
Exactly. Low voltage lighting is a resistive load so the designers don't have to design for an inductive component.
as a side issue - since I'm converting my MV6 interior to a 3 piece suite - can a PC power supply be used to power motors?
Probably. PC power supplies can provide surprisingly high current at 12v (and 5v). Don't know if it is enough to power Omega seat motors though.
Old ones have proper on/off switches. Newer ones need the motherboard to tell them when to go from standby to 'on'. They are designed to be fan cooled so you may find the noise irritating and they will need a safe enclosure as the standard unit is normally safely enclosed in the PC case.