Dual Primarys

[Overclocked]

I have the following transformer (Pic at end of document), and it has Dual Primarys. Do I have to connect the 2 primarys in parallel or series in order to get the specified output? Can I just use 1 primary or do I have to use both?

**broken link removed**

 

[ljcox]

My reading of the label is that for a 110 Volt input, you only need to use one primary. But for 220 Volt, you need to connect them in series. Be sure to connect them in series aiding (ie. connect 2 & 3), not series opposing.

 

[audioguru]

I think both primaries should be paralleled for it to deliver full power from 110V. With only a single primary then it might overheat.
Connect black to black and white to white. :lol:

 

[Nigel Goodwin]

Yes, you connect them in parallel for 110V and in series for 220V, using just half the primary will reduce the transformer to half power.

 

[JimB]

For correct operation at 110volts, connect the primaries in parallel, black to black and white to white.

For correct operation at 220volts, connect the primaries in series. Link wires 2 and 3 together, then put the 220v to wires 1 and 4.

It is important that the primaries are connected with the correct phasing, otherwise there will be smell of hot transformer when connected to the mains!

JimB

 

[Dr.EM]

I just find it wierd how it says 110v OR 220v, and they are specfied at different frequencies. And, in series, surely the 110 and 220 windings = 330v? I don't know much about transformers, but this looks like an older one, mabye its different? I know the newer ones tend to have dual 110v windings, so in series I can see how it gives 220v, or in parallel 110v. I'm sure you are right, I just can't quite see how its supposed to add up :?:

 

[Nigel Goodwin]

I just find it wierd how it says 110v OR 220v, and they are specfied at different frequencies. And, in series, surely the 110 and 220 windings = 330v? I don't know much about transformers, but this looks like an older one, mabye its different? I know the newer ones tend to have dual 110v windings, so in series I can see how it gives 220v, or in parallel 110v. I'm sure you are right, I just can't quite see how its supposed to add up :?:

You're reading the transformer wrong!.

It has TWO 110V windings (the frequency is irrelevant), which you put in parallel for 110V and series for 220V.

The label is for how it can be wired, and NOT for each winding.

 

[audioguru]

... otherwise there will be smell of hot transformer when connected to the mains!

Jim, your understatement is hillarious!
I've smelled "hot transformer" many times but never smoke and flames.
I think it would also make a deafening buzz while it is burning. :lol:

 

[JimB]

Many years ago, in a previous life, I worked in a shipyard.
In that shipyard many things defied all reasonable logic.
One of the tasks I had to carry out was laying strain gauges. If the strain gauge was to be attached to something which got hot in normal operation we would use a high temperature glue which needed a high temperature to cure it. To get the high temperature we used a small low voltage heating pad, powered from the normal 240v mains by a transformer.

One day, having just layed the gauge and powered up the heating pad, it didnt get hot, no supply to the transformer.
Called the electrician who traced the mains lead back to the distribution board and declared that the fuse had blown.
He replaced the fuse and on re-inserting the fuse carrier he was showered in sparks and molten copper!
It turned out that the supply was DC, but connected out into the workshop on a distribution board with the usual 240v sockets. On opening up the transformer box, it was smoked. Even though it had only had the DC supply for less than a second.

Find the correct supply, get another transformer, start again.
Happy days (some of them).
JimB

 

[audioguru]

Many years ago, in a previous life, I worked in a shipyard.

I can't remember any of my previous lives. I have been an electronics geek all of this life.

He replaced the fuse and on re-inserting the fuse carrier he was showered in sparks and molten copper!

I saw the same thing when a guy connected a 120V transformer to 540V. The wire-nuts and wires to the transformer dissappeared.
The same guy tried to fix a leaky water pipe with a blow-torch with the water pressure still on. Guess how big a flood was caused.

Happy days (some of them).

The past few days have been happy with mild weather. The snow melted and was nearly gone. Now it is snowing like crazy! I won't be very happy shovelling the stuff but the days are getting longer so I'll think about summer coming.

Happy New Year

 

[Nigel Goodwin]

A women bought a Sony record deck in for repair yesterday, her husband wanted to use it to connect to his computer to transfer records to CD. Seeing as he hadn't got an RIAA preamp it wouldn't have worked anyway, but worst of all it was low voltage powered from the Sony unit. So he cut off the 12V DC power connector and wired a 230V 13A plug to it :lol:

The leaf switch that turns the motor ON had completely lost one of it's 'leaves' (apparently vapourised!), and the contacts on the motor PCB were melted and burnt off :lol:

Needless to say, we sold him a new deck, this one mains powered AND containing a switchable RIAA preamp!.

 

[audioguru]

Vinyl records player? Oh yeah, I still have mine. It is a Dual 1009 with Shure's second-best cartridge.
My rich audiophile friend always got the latest and best cartridge and gave me his hand-me-downs. :lol: