transformer question

[enthalpystudios]

well, used parchment paper its all i had, hopefully not too bad for a first tranny:

gonna get to testing tomorrow.... right now i just ohmed it out, have dcr of 8.3 on the pri, 23.8 on the sec.

whats a decent couple tests i can put 'er through cj?

thanks for the help guys

billy

 

[enthalpystudios]

reading some stuff about testing transformers.

i need a damn signal gen!!!

maybe i can find a freeware program.... would be good enough for low level stuff, actually, the 'main out' on my motu can drive pretty high.... enough anyway

i guess the obvious stuff is easy enough to do with just a scope.... -3db points, phase.....

and dbl checking i got the ratio ok, of course..... also i guess i can check for ringing ( ithink i remember screenshots of you doing this, CJ), and can i look for peaks and what not just by sweeping and watching the scope?

maybe white noise and some type of FFT on the computer??

well anyway, its like 330 in the morning or something

i can do this stufffff tomorrow

 

[CJ]

Nice going!
You could do the best test, which is to wire it up and listen.

Did you put in a layer of insl between the pri and sec?
Don't know what voltages that thing will see...

You could use 60 hz just to see if it works.
Get the turns ratio, use a variac!
Or just put in 6.3 from a filament xfmr to see what comes out the other end.

 

[enthalpystudios]

yup, insulated with wax paper.... that ok?

going to put a 60hz from wavelab into the pri and use the dmm to check vrms, and the scope for visual Vpeak checking, but yeah, i'm going to try and get it into this g1176 circuit later tonight....

except that theres api's waitin to be finished, and a couple new 4' pieces of 3" garolite on the kitchen table ;]

and a new stepbit that does 24mm ;]

but yeah, i'm pumped, can't wait to try it in the g1176 cct

 

[enthalpystudios]

on this b11178 real quick, i loaded some testones into nuendo. 60, 300, and 1K, square and sine, and sent them at a low(er) level into the primary, and then the secondary back in, out of a MOTU and back into a MOTU, no loading or anything like that, i'd imagine source Z is real low and load Z is real high. cant find specs on the MOTU anywhere, not real ones with specified Z's.

so anyway, I was getting about 5.3db of step up, and this is with the nuendo meters... all test tones gave about the same measurements. so i probably botched something.... perhaps i need the 26ga, although I figured the gauge shouldnt affect the turns ratio.

anyway, probably my counting ;]

also, is there a better test bed for this, should i terminate either end or anything?

also, i tried out audiotester, from http://www.audiotester.de/, but i had a real hard time calibrating it with my motu 2408... maybe need a 'regular' sound card?

but i just burned some test tones to cd and borrowed a boombox, so i'm going to give it a shot with that and the scope to see what the deal is.... should work until i get a function gen somewhere.

billy

 

[edanderson]

i don't know if your motu can really drive the b11178, which may be making problems for you. i think you're better off doing what CJ recommended and get a power transformer that puts out a low voltage, like 6VAC, and put that into the primary. measure the AC voltage with a voltmeter on the primary and the secondary.

or just skip that and put it in circuit. the g1176 output driver has enough to oomph to properly drive the transformer.

ed

 

[enthalpystudios]

yup, got it in circuit now.

switched my input to 5532. working pretty well... i still think i should make a better way to massively test fet's so that i can get me threshold down where i want it.

i'll scope it out before and after the tranny in circuit in a little bit after i recalibrate.

thanks ed

billy