[BUILD] 1176LN Rev D DIY

[Harpo]

I couldn't readily find the datasheet for my avel linberg toroidal transformer from Hairball, but for argument sake, let's assume it's efficiency is 80%.

84.8% from http://www.avellindberg.com/transformers/y23_range_specs.htm.
I'd pick a common 500mA/t if a 400mA/t (something like ESKA type-No. 522.513 for size 5x20mm) is not available.

 

[U87610]

Thanks for your input Harpo!! I picked up some 500 mA time lag fuses, since they were readily available. 

 

[Bellico]

What is your DC voltage at the cathode (side with the line) of CR7 and CR8?

What is your DC voltage at the anode (side without the line) of CR9 and CR10?

CR7 = 24.4v
CR8 = 24.4v
CR9 = 20v
CR10 = 20v

 

[Echo North]

What is your DC voltage at the cathode (side with the line) of CR7 and CR8?

What is your DC voltage at the anode (side without the line) of CR9 and CR10?

CR7 = 24.4v
CR8 = 24.4v
CR9 = 20v
CR10 = 20v

And you have nothing between your CT and your test points?

 

[Bellico]

What is your DC voltage at the cathode (side with the line) of CR7 and CR8?

What is your DC voltage at the anode (side without the line) of CR9 and CR10?

CR7 = 24.4v
CR8 = 24.4v
CR9 = 20v
CR10 = 20v

And you have nothing between your CT and your test points?

I got nothing on AC and DC gives me 0 on the 30v rail and 21.4 on the 10v rail

that was last night. 

I decided to double check this morning and somehow all the values are different.

CR7 = 16v
CR8 = 16v
CR9 = 10.6v
CR10 = 10.6v

0 on the 30 rail and +10.6 on the -10v test point. 

I then switched the unit off and unplugged it.  Then for the sake of experiment I plugged it back in and tested again.

CR7 = 16v
CR8 = 16v
CR9 = 5.6v
CR10 = 5.6v

all I have done between taking these readings is turned the unit off and un plugged it. 

I'm plugged into a power conditioner and the power in my building has always been good aside from radio disney showing up in the ground. 

 

[Harpo]

Low battery in your multimeter ?

 

[Bellico]

Low battery in your multimeter ?

i wish.  checked that.

 

[Bellico]

even with these problems, shouldn't I be getting at least light on the VU.  the resistor is fine between the power transfo and the VU light.  the bulb seems fine.  the only thing I can come up with in my little pea of a brain is the power transfo is messed up. 

Everything we did on the 2 units is identical.  we matched every component between the 2 and placed them exactly the same. 

 

[Harpo]

Fault might be missing center tap related. What manufacturer and type is your dual secondary or center tapped secondary transformer and if it is dual primary windings, did you connect these in parallel for your 115V AC mains?

 

[Bellico]

Fault might be missing center tap related. What manufacturer and type is your dual secondary or center tapped secondary transformer and if it is dual primary windings, did you connect these in parallel for your 115V AC mains?

It's the Avel Lindberg transfo.  secondaries are connected exactly as they are supposed to be.

as I said we built 2 units, one black and one silver.  every wire and component is identical and matched so the 2 could be used in stereo.  the black one is calibrated and working wonderfully, the silver one is dead. 

 

[Harpo]

It's the Avel Lindberg transfo.  secondaries are connected exactly as they are supposed to be.

..and this company builds lots of different type transformers. What transformer do you physically have (might be different from what you have ordered).
From "My secondaries are reading 18v straight of the power tranfo." I read it as at least dual secondaries and an unloaded secondary winding measuring 18VAC might indicate, your secondaries might be 2x 15VAC with high mains or 2x 18VAC with lower than 115VAC mains at whatever VA rating when you wanted a dual 25VAC or center tapped 50VAC secondary.

 

[Bellico]

model # Y236106

exactly the same as the one in the unit that is working. 

2x115v primaries

grey
blue
purple
brown

2x 25v secondaries

BLK 0v
red 25v/0.60A

orange 0v
yellow 25v / 0.60A

The transfo was ordered from hairball.  we ordered the 2 kits on the same order from HB, they simply mistakenly sent us one with a black face case.  all other components and parts are identical. 

 

[Harpo]

If you connected the primary windings in parallel (blue+purple and grey+brown) and secondary windings in series (red+orange joined for the center tap connection), your transformer secondary AC voltage readings wouldn't be 18V between the center tap and each of the outer secondary black or yellow wires, or your transformer is toast/mislabled.

 

[Bellico]

If you connected the primary windings in parallel (blue+purple and grey+brown) and secondary windings in series (red+orange joined for the center tap connection), your transformer secondary AC voltage readings wouldn't be 18V between the center tap and each of the outer secondary black or yellow wires, or your transformer is toast/mislabled.

I have it wired as I do the other and as instructed in the wiring guide...

primaries in parallel (blue+purple and grey+brown)

secondaries:
orange and black to the CT (the two 0v's)
red and yellow to the AC's (the two 25v's)


A bad power transfo is what I thought from the very beginning of my problems.  How can I confirm that it is the transfo?

 

[Harpo]

If you connected the primary windings in parallel (blue+purple and grey+brown) and secondary windings in series (red+orange joined for the center tap connection), your transformer secondary AC voltage readings wouldn't be 18V between the center tap and each of the outer secondary black or yellow wires, or your transformer is toast/mislabled.

I have it wired as I do the other and as instructed in the wiring guide...

primaries in parallel (blue+purple and grey+brown)

secondaries:
orange and black to the CT (the two 0v's)
red and yellow to the AC's (the two 25v's)


A bad power transfo is what I thought from the very beginning of my problems.  How can I confirm that it is the transfo?

Probably nothing wrong with your transformer. You have joined the secondary windings out of phase. Maybe read the wiring guide, the transformer datasheet or http://web.archive.org/web/20090914070140/http://www.diyfactory.com/data/transformer_connections.gif again.

 

[Bellico]

can you explain why the other unit works perfectly wired with that configuration. 

the two 0v secondaries to the CT's and the 25v secondaries to the AC's

 

[Echo North]

can you explain why the other unit works perfectly wired with that configuration. 

the two 0v secondaries to the CT's and the 25v secondaries to the AC's

No idea.

Head my new power transformer wring guide as well:
http://hairballaudio.com/docs/FETGUIDE/Section%20D%20-%20Power%20Section.pdf

 

[Bellico]

OK

now I'm really confused. 

We had a working unit and a non working one.  populated identically, same components, matched and tested. 

secondaries wired in parallel on both.  one worked. 

I tried wiring in series like your new guide shows and still got nothing.  still passing current but not even close to the numbers I should be seeing 

now, we tried wiring the other one (black face) as it shows in the new guide and it doesn't work like that, but it worked when the secondaries are in parallel

The silver face still doesn't work either way.  it wont even power the light direct either way.

There were several posts on this thread advising to run the secondaries in parallel. 

Mike can I PM you on this?

Everyone is "new" in something different.
It's not a shame to ask.
Please hurry, because i need go to sleep (but don't kill yourself by voltage)

I hope that youre alive
I'm going to sleep.
If you measure different voltages, that you should have -  leave it for now, because you can damage something more.
Your problem is probably on a point where you conected secondary windings.

Your connection:

YELLOW (one side)
RED and ORANGE (center)
BLACK (other side)

Should be:

YELLOW (one side)
BLACK and ORANGE (center)
RED (other side)

I hope it will works now!

Goodnight

I don't think so. The transformer wiring seems correct to me...
Check the attachment if you're not sure.

[/quote]

 

[Echo North]

The secondaries are wired with a "Split Secondary".  This should not be confused with parallel which look similar but is VERY different.

The end of winding 1 and the start of winding 2 are connect at the "CT" pad.  This is your ground/common reference.  All DC measurements should be made referencing this point.  The remanning "outside" wires each go to one of the AC pads.  This creates two AC 25V secondaries (though I think it ends up being 30 under load).  One is rectified and regulated to +30VDC and the other is rectified and dropped to -10VDC (both referenced against the CT pad).

Mike

 

[Echo North]

Never I have hear anyone say to run the secondaries in parallel.  It simply will never work that way.  Laws of physics say no.

I think the error is in your test method. Or you have an error on the board.

What do you have stuffed?  Just the power section?