Request help in selecting transformer from Digikey

[[email protected]]

I apologize if my queries sound silly, so pardon me.
The truth is that I have used transformers in my
work for a long time, but never bought it myself --
someone else bought the required ones as per my
specifications. Now I have to buy some from an
online store as Digikey, and am confused, with all
details presented to me.
I want a 120 V AC -> 9 - 0 - 9 Volt 2 Amp AC
transformer. I am also comfortable with two
120 V AC -> 9 - 0 - 9 Volt 1 Amp AC transformers
connected in parallel, as I have found this
to be a very convenient configuration, both
in terms of space occupied by the transformers
as well as weight and cost. So I navigated to:
http://www.digikey.com/product-search/en/transformers/power-transformers/786735?k=power transformer

However, a lot of the presented data confused me.
1. Who is a reputed manufacturer ?
2. What exactly is the 'Series' supposed to mean?
3. Voltage Secondary (Full Load) Now I fully
understand what "Parallel 9 V, Series 18 V" means,
but why is '18V' listed below ?
4. Same confusion as for item 3 above holds for
Current Output (Max) list - Why for example is
'Parallel 1.02 A, Series 533 mA' listes at the
top of the list, but later in the same list is
the item '1.06 A' ? Even more confusing are items
in the same list : '575 mA, 5 A, 6 A' -- are these
some special type of transformers ?
Could any electronics guru please help me clear
all the confusion ? Thanks in advance for your
help.

 

[Phil Allison]

I apologize if my queries sound silly, so pardon me.
The truth is that I have used transformers in my
work for a long time, but never bought it myself --
someone else bought the required ones as per my
specifications. Now I have to buy some from an
online store as Digikey, and am confused, with all
details presented to me.

**The transformer search is dreadful, confuse anyone.

I want a 120 V AC -> 9 - 0 - 9 Volt 2 Amp AC
transformer. I am also comfortable with two
120 V AC -> 9 - 0 - 9 Volt 1 Amp AC transformers
connected in parallel, as I have found this
to be a very convenient configuration, both
in terms of space occupied by the transformers
as well as weight and cost. So I navigated to:
http://www.digikey.com/product-search/en/transformers/power-transformers/786735?k=power transformer

However, a lot of the presented data confused me.

** What it seems you HAVE to do is find the tranny you want at the maker web
site and note down all the details.

Then, transfer that data into the Digikey search engine and it will see if
they have any.

OTOH, just wade through all the pages of line items until you stumble on it.

IME, a printed catalogue is WAYYYYY easier to use.

Tannys are simply listed by brand, ratings and price.

Find what you want in seconds.



..... Phil

 

[Spehro Pefhany]

On Tue, 19 Nov 2013 20:36:27 -0800 (PST), the renowned

I apologize if my queries sound silly, so pardon me.
The truth is that I have used transformers in my
work for a long time, but never bought it myself --
someone else bought the required ones as per my
specifications. Now I have to buy some from an
online store as Digikey, and am confused, with all
details presented to me.
I want a 120 V AC -> 9 - 0 - 9 Volt 2 Amp AC
transformer. I am also comfortable with two
120 V AC -> 9 - 0 - 9 Volt 1 Amp AC transformers
connected in parallel, as I have found this
to be a very convenient configuration, both
in terms of space occupied by the transformers
as well as weight and cost. So I navigated to:
http://www.digikey.com/product-search/en/transformers/power-transformers/786735?k=power transformer

However, a lot of the presented data confused me.
1. Who is a reputed manufacturer ?

Any of the ones Digikey sell are okay, IMHO. Make sure they have the
appropriate safety agency listings for the market you're addressing.
There are many, many others who are not okay.

2. What exactly is the 'Series' supposed to mean?

The manufacturer's designation. If it was a car, it would be Buick or
Chevy etc. for GM, and something else for Kia, Daihatsu, Land Rover,
etc.

3. Voltage Secondary (Full Load) Now I fully
understand what "Parallel 9 V, Series 18 V" means,
but why is '18V' listed below ?

Many of the transformers have two isolated secondaries that can be
connected in series or in parallel. Many have only one secondary
winding. The sorting order in their lists is sort of irrelevant, I
think, as long as you realize it exists.

4. Same confusion as for item 3 above holds for
Current Output (Max) list - Why for example is
'Parallel 1.02 A, Series 533 mA' listes at the
top of the list, but later in the same list is
the item '1.06 A' ?

Again, it's some arbitrary sorting thing. That's not too annoying.
Their engine gets tempcos completely mixed up.

Even more confusing are items
in the same list : '575 mA, 5 A, 6 A' -- are these
some special type of transformers ?

Click on them (there are only two) and you'll find they're ye olde
tube tranformers* with asymmetric (filament and plate) windings.
They're also > $150 a pop.

Could any electronics guru please help me clear
all the confusion ? Thanks in advance for your
help.

Just flip through a few dozen data sheets and you'll figure it out,
and if not, I'm afraid a modest USENET posting isn't going to help
much.

*Not to be confused with transformer tubes, which are apparently some
kind of drug paraphenalia: http://transformertubes.com/


Best regards,
Spehro Pefhany

 

[amdx]

Oh, but Spehro, the web site _clearly states_ that those are for
_tobacco_!

What's with the flash of a different screen for about a second before
the bong page .
Here's a sceenprint I caught.

 

[amdx]

What's with the flash of a different screen for about a second before
the bong page .
Here's a sceenprint I caught.

Never mind, I see it now.

 

[John Devereux]

What's with the flash of a different screen for about a second before
the bong page .

That's the FBI installing the malware to report on your activities.

 

[Spehro Pefhany]

Oh, but Spehro, the web site _clearly states_ that those are for
_tobacco_!

LOL. If it says so on the Internet it must be true.

--sp

 

[[email protected]]

The truth is that I have used transformers in my

work for a long time, but never bought it myself --

someone else bought the required ones as per my

specifications.

So your dad isn't buying them for you anymore?

 

[Greegor]

Dan > The truth is that I have used transformers in my
Dan > work for a long time, but never bought it myself --
Dan > someone else bought the required ones as per my
Dan > specifications.

bloggs > So your dad isn't buying them for you anymore?

ROFL