1176 RevA power xfrmr

Hello,
I am planning on building one of mnats' 1176 RevA boards and have a question for you gentlemen. I need a 50V CT power xfrmr. I am and somewhat of a beginner and was wondering if this part number from Mouser would work: 166G50 
I live in the U.S., so I have selected the mains accordingly, this much I do know. Any help would be great.

Thanks.

That part doesn't appear to be in stock?  I don't see anything wrong with it, but don't take my word for it...I'm no PT expert.

The part I would suggest and will cost you about $22 is the Avel Lindberg Y236106.

http://www.avellindberg.com/transformers/y23_range_specs.htm

These are the PT's of choice for these projects I would say...definitely tried and tested.  To order you'll have to call over the phone.

If you're looking to save on shipping I can see where you may want to bundle with another order from Mouser...but you'll need to find something on stock and many of their comparable e PT's cost more then the Avel Lindberg with shipping.

Thanks,

Mike

No, thank you. And, I will be ordering some parts for this project (in/out xfrms and knobs) from your site.

I checked out the part # and it looks good. They specify the secondary volatge (V) as 25+25. Is this safe to assume the center tap =50V?
Anyone else building the RevA? I haven't received my boards from mnats yet but they are on their way. Just doing pre-production.

Yes it definitely can be wired with a center tap.

Thanks!

Mike

If you're new to wiring PT's here is a link (also on Mako's site) that will make things a lot easier.  I have this taped to my wall.

http://www.diyfactory.com/data/transformer_connections.gif

Mike

I say go with a toroidal trafo. The one from mouser doesn't seem to be. It may be OK, but toroids are less prone to cause interference. Check with avel lindberg or for a little less $$ you can go with www.antekinc.com...  The AN-0225 is 20VA and the AN-0525 is 50VA... I don't remember which one I bought for my 2 rev Ds but they cost $11 and $13 respectively. Can't beat that! Many people have used them here so they should work just fine.  You should call them though, I have heard they could be a bit less responsive over email.

Speaking of wiring power transformers, I've always switched the HOT of the AC.  I noticed in this Purple MC77 that I'm working on right now they say to switch the Neutral - is this normal??  I was always told it was dangerous and not recommended...

So many opinions, so little time on this earth...

Sig

I was always confused by this too. 

I spoke with Andrew from Purple a few months ago and asked him.

If I recall correctly, he explained he preferred to switch the neutral (where the voltage was near 0) to protect someone from getting a higher voltage shock from a failed switch or from poking around inside by the the switch.

I'm not so sure I fully understood as this could be unsafe in other ways.

Ed may have some better info on this.

Mike

Well you get an open circuit either way. And there's always a 110 or whatever your mains is drop across the switch when open. ("this could be unsafe in other ways")

There's just this thing that if the hot is disconnected by the switch it doesn't make it into the trafo in the first place, so there's less wiring in total that can zap anything or anyone...then again if the grounding is right this isn't an issue anyway, and you have to keep your paws away from hot stuff anyway, and you shrinkhose everything anyway, and the electrons themselves don't give a flying f** about where you put the switch, they're gonna zap you coming and going if you paw them. They'll just be waiting at the other side of trafo if you disconnect 0.

Enter the Germans, over here you can plug a plug in whichever way you want, nullifying the issue. So they have their version: Disconnect both of them with a DPST switch.

Keeps mains voltage stuff short for sure, but the switch still has the same fangs.

> I've always switched the HOT of the AC.  ... they say to switch the Neutral - is this normal??

In Permanent in-Wall House Wiring, you may NOT switch the white wire. (Talking USA code here.)

Inside plug-connected appliances, ALWAYS UN-PLUG before you stick a hand inside. So it does not matter which side you switch. I lean to "hot", but sometimes the other way is easier or neater.

NEVER Assume either or any of the holes in the wall is hot, low, or Ground!!! 60% of the outlets in my kitchen had white/black reversed. Didn't matter so much because ALL the annoying greens were cut short at the cable and unconnected at the receptacle.

> Germans, over here you can plug a plug in whichever way you want

All older US outlets are that way too. It appears that some UK plugs may be broken to allow reversed connection to some outlets (though the several safety details make this harder in the UK than most places).

IMHO, it was a mistake to ever pretend we could know which was which. Codes, diagrams, regulations are NOT field wiring. Ignorance is universal. "ALL" holes are HOT, unless you need them to be hot, then they are not. The most you can be 90% sure of is that one will be 115V hotter than another.

Hey guys, this is my first time wiring up a toroidal power xformer for my Rev A and I want to be as safe as possible.  I purchased the Avel Lindberg Y236106 xformer and think I have the wiring figured out, but figured I'd ask to see if anyone had a picture/drawing of theirs.  I've searched the forums, but haven't found anything on the wiring of the avel.  Thanks!  Sorry I'm a newbie, but don't want to die of electrical shock

At your IEC inlet:

Ground: To Chassis
Neutral: Blue/Violet
Live: Grey/Brown

At your board:
0V center: Red/Orange
Then Black and yellow...one on each side.

Mike

Thanks Mike!!  I figured that was the correct way, just wanted to make sure

I used a Y236207 on my 1176's. Very cheap if ya buy 2. I use a combined fuse/power switch/iec. And switch the hot wire. But is on back of the 1176. And my other projects...