Power Transformer Teardown - Small - 1.5 VA

[CJ]

here we go again,

there was some going's on about winding a small pwr xfmr,  just happened to run into one,

120 to about 20 V-ac,  about 1.5 watts,

 

[CJ]

somebody must have ripped the roof off a barn somewhere and stamped these lams, even with a 1 x 1 lace up the core only does 2100 in the u-eff dept.

that is ok, means we can gin up the flux level up and save turns,

 

[CJ]

KP wrapper and lead plates, random wound, 

about 2400 turns primary which Gausses out at about 17 KG, whoa!

barn roof lams probably do 21 KG or better, so no worries, how hot can a EI 375 core get?

 

[CJ]

lonely bobbin has lost it's companions,

1/2" stack of lams with a 3/8" tongue, so 1.33 core aspect ratio which extends flux level,

 

[CJ]

and here is your print, with some educational material like a regulation formula,

we clock out at about 9% which is typical for a small transformer like this,

no hum, no heat, do not like the random wind for mains work but that has been going on for years, so wtf.

i'm jus sayin... 

 

[warpie]

Missed these posts...  ;D

 

[gyraf]

*like*