Mystery Transformer Identification

[Jaxn]

Ive got one of those new usb turntables to repair for a friend (he decided to force the US 120VAC plug into our Australian 240VAC), and it will be easy enough to replace but the only problem is i can't find any info on the transformer or even to turntable.

The Primary is completely ruined and i need to know what voltage goes to the circuit post transformer.

Markings are:

TF35951201UL
YN95007-1

Im assuming from the first serial number that the 120 relates to 120VAC input, is there anything else someone can discern from these?

Thanks.

[Enzo]

What make and model is the turntable anyway?

DOn't try to read too much into the part number. Chances are good that the part was custom wound for whoever made the table, and the actual brand may not be available to you as a part. Not saying it isn't, but good chance it is not. Point is it is real unlikely the transformer is an off the shelf item. Turntable company goes to transformer company and says, make us 25,000 transformers that take 240v in and make 24v center tapped out at 750ma. Or whatever. And they say, OK, we'll do it.

Let's consider the problem. You have the old part and the turntable, so we can find out some things. How many secondary wires are there? And if they are intact windings, how many windings? The resistances won't tell us much, but you can find out what is a center tap and what isn't.

There will be power for the motor, and power for the control circuits, and power for the USB interface. SOme of those power sources may be shared. You should be able to find where the AC from the transformer goes, and I expect it will go to some rectifiers and filters. You should be able to spot if it uses split supplies like +12 and -12, or a single supply like +24. Are there three-legged voltage regulator ICs? You might have 24v for the motor and 5v for the logic, or even 3.3v for a processor - look for regulators.

Look at the main filter caps. If you see 35v caps, probably expect 25v tops for the supplies. REgulators like a few extra volts of headroom to regulate down from, so if there are 12 regulators, then 16-20v going into them sounds average. If we can get an idea of the DC involved, we can easily calculate what the AC would be to create those DC voltages.

And one thing in your favor is that it probably doesn;t have to be all that close. If all the operating voltages are regulated - likely - then as long as the input voltage is high enough for that couple volt headroom, but not so high as to cook the things, you should be OK.

[Jaxn]

Its an ION Profile LP.

There are 4 1N4*** diodes arranged as a rectifier and also a single package second rectifier (W01M).
BA033 is a 3.3v regulator.
KIA78S08P is an 8v regulator.
25v filter caps...all caps are actually 25v
Its a double sided board with a ground plane covering one side and the component side has really narrow traces and is all SMD except for electros, but it appears that the diodes are for the motor and the second rectifier is for everything else.

The transformer only has 2 red wires for the primary and 2 blue from the secondary. I still get resistance across the blues but as you said that isn't very helpful.

My knowledge is mainly guitar pedals and on the pcb is a 4558 and a tl074 so i would assume that it is running a split supply but the rails for the opamps aren't being regulated?

[oc disorder]

G'day try this

rats.. doesn't seem to show the voltage

If you can find a reference to this motor MEM09S12U15-6 DC MOTOR perhaps this may help.

My guess is aprox 10v DC

Here's a link to a more sophisticated one with the same motor may give a clue

http://www.ionaudio.com/downloads/LP%202%20CD%20-%20Service%20Manual.pdf

[Jaxn]

That appears to be the correct model, the pcb layout matches exactly.

The motor has 9v, 12v marked on the side, is likely then, that there is 12vac coming out of the transformer?

If i attach a power supply i have and set it to 9v then if i increase the voltage until the record is playing at the correct speed i'll know the correct voltage and what transformer to get.

[oc disorder]

I meant to say approx 10v AC .

Usually the voltage into a regulator is aprox 3 volts above the output of the regulator.

The motor may have inbuilt regulation so you may find there is no difference between feeding
it 9v DC and 12v DC. But if you have a known dc supply hooking that up directly to the motor
may help you figure it out. I expect as the motor has 4 connections 2 to the 33/45rpm speed
control there must be a bit of electronics in the motor.
I couldn't find any reference to the motor apart from their site.

Where does CN5 go I couldn't spot it.

[Jaxn]

As far as i can tellCN5 is not connected to anything, its just empty pads on the pcb. It may run somewhere, but tracing the pcb is incredibly difficult, even in good light with a magnifying glass.

[Enzo]

CN5 looks like it might be used on some other model that shares this board. Perhaps a fancier one with a light near the stylus landing point or something.

I would agree that the motor likely looks after itself, and the voltage to it is not critical.

[Jaxn]

I thought i had this all sorted out, but trying to find a transformer that goes 240vac to 10vac is pretty much impossible.

Would i get away with 12v (too high) or 9v (too low)?

Im swaying towards 9v as the regulator that down to 8v and the motor would then be running off pretty close to 9v.

Thanks for all the help as well.

[oc disorder]

I think 9v AC would be fine maybe a 1 amp one.
The Jaycar MM2002 @AU$11.95 has 6.5v,7.5v,8.5v,9.5v,12.6v and 15 volt tappings and a thermal fuse
which means you could cautiously try the 8.5 and 9.5 tappings and check what the DC output is and if
the player works ok. I find their transformers are slightly above the stated figures even when loaded
so you may even like to start on the 7.5 volt tapping.
Let us know how it goes and hope your friend didn't destroy some vital component.
Of course you could always contact the distributor and see if they can supply populated boards and
even export transformers suitable for downunder - upside down mounting of course !

[luistadeu]

alguem tem o pdf dele?

[luistadeu]

G'day try this

rats.. doesn't seem to show the voltage

If you can find a reference to this motor MEM09S12U15-6 DC MOTOR perhaps this may help.

My guess is aprox 10v DC

Here's a link to a more sophisticated one with the same motor may give a clue

http://www.ionaudio.com/downloads/LP%202%20CD%20-%20Service%20Manual.pdf

Alguem tem o PDF para baixar pelo MEGA ?

[eschertron]

Alguem tem o PDF para baixar pelo MEGA ?

You'll get more help if you let us know where you reside or what language we need to translate from

[Jazz P Bass]

Alguem tem o PDF para baixar pelo MEGA ?

Portuguese.
"Someone has the PDF to download by MEGA"

[Jazz P Bass]

alguem tem o pdf dele?

Portuguese
"Does anyone have his PDF?"