couple q's about transformer

[mich]

hi all.

1. i have the oep transformer (1:6.45) and its shield can,and i read somewhere that u have to solder the can for sealing it. should it be sealed all the way?(or the 4 corners e.g)

2. will it be better conected paraleled or in series ?(the mic side on api preamp)

thanks.

 

[rafafredd]

I just put a little solder at the center of each side of the shield can on my OEPs.

For the API, try 1+1 in series and 6.45+6.45 also in series. This way you will have higher inductances on both the primary and the secondary, and 1:6.45 turns should be enought with the API/melcor opamp. Then, if you want to try it a 1:12.90, just change the primary to parallel connection, or use one winding and ground one of the pins of the other winding.

 

[mich]

thanks rafa.
do u think it might be faulty transformer?dc resistence reads fine,
but i cant seem to get signal out of it...
im feeding 100mV of 1Khz into the primaries (on both sides with the windings in series) and secondries one leg to ground,(conected in series as well)-and nothing on the output....?!

any suggestions?

 

[mich]

someone? :roll: :shock: :sad:

 

[gyraf]

Try again. If DC resistance reads right, then it works. maybe you wired out-of-phase.

Jakob E.

 

[mich]

wow !

i really dont know what am i doing wrong....!
:evil:

 

[bluebird]

Do you know what wiring out of phase means?

it means when you connect the two windings in parallel or series you have to connect + and - of each winding correctly. if there is a diagram for the transformer, the + end of the winding is usually marked with a dot.

For parallel connect the dots together. for series connect the windings like you would two AA batterys + (dot) to - (no dot)...

 

[mich]

i knew those points ment something..... :razz:

thanks a lot.

cant get the diagram of this model but i have a diagram of another one from the same series.

 

[mich]

sorry for my newbines, its my first transformer project.... :?

im conecting the primaries (the windings in series, + to - of each winding of primaries) to the same feed (ac 100mV @ 1 Khz), the screen to ground, and measuring secondries (in series just like the primaries) with one side to ground.nothing.

the only way im getting the signal out is conecting one side of the primaries to ground.but thats not balanced...