toroid transformer help

[j2sip]

Hi,

Newbie po. PAtulong naman sa problema ko.

The Toroid transformer in question. Gusto ko sana gamitin sa CNC machine ko. GAwin kong 35v powersupply.



I got it from a UPS power-off delay. The unit says 650VA and there's a marking that says "LPTP500-20". The two red wires were joined together.
Tanong ko po:

1. What should I use from the 3 primary wires for my 220V input? colors are BLUE, RED, WHITE.

2. As you can see, there are 5 secondary wires. From the picture: Orange - Orange - Grey - Brown - Blue.
What should I use to get the 12 - 0 - 12 configuration assuming secondary is 12V?

If it's of any help, the RED wires were connected to the + terminal of the unit's 12V battery. The WHITE and BLUE ones were plugged into the unit's board. The cream connector was plugged into the board as well, which has "BATTERY" marking inline with the RED terminal and a "GROUND" marking where the GREY wire is.

Salamat po.


Jordan

[RiDdLeR???]

Mahirap mag-assume based on pictures lang.  Make a schematic of the torroid by checking the continuity or resistance, alamin mo muna kung anong mga terminals ang magkakadikit electrically.

[j2sip]

That's what i'm about to ask next kung my maitutulong pag my actual measurements na nakukuha. Multimeter po kelangan dito, right? If I may po, ano po ang iexpect ko na measurements across the leads? Pasenxa na po, tlgang zero ako electronically.

Salamat.
Jordan

[gie62]

kung nasa iyo pa yung ups na pinagtanggalan mo nyang transformer, doon makikita mo yung primary connection ng transformer. tignan mo na din yung ac supply nya kung 110 o 220 vac.
kung sakaling alam mo na yung primary at 220vac ito, kabitan mo ng ac plug ang primary at plug mo sa outlet. ngayon masusukat mo na yung mga secondary voltage nyang transformer.

[j2sip]

gie62,

Nakarektang nakakabit sa +terminal ng battery yung RED wire na ngmula sa grupo ng 3 16gauge wires. Tz yung BLUE AT WHITE nakasaksak sa board. So either of them is the -.

 HAy, bili muna yata ako ng DMM, ngaun lng kc ako ngkainterest sa electronics. Salamat sa sagot nyo, I'll update nalang after I got the readings.

Thanks. 

[tony]

be suspicious of transformers taken from UPS's they could have the low voltage windings connected to the high voltage windings.......

transformers for UPS's serve a different finction, check and double check, be safe.....

[???]

Sir tony link naman dyan nung calculation sa toroid transformer para sa pagwind. Tnx.

[tony]

ito ang rule of thumb ko sa calculations: number of turns at 230v primary = 1750/cross-section area in square inches.....

applicable to both EI and torroids, only difference is with torroids the magnetizing current will be much lower than in the EI so that you can use fewer turns.

[???]

Oy tnx, sir tony, masubukan ko nga ito.

[j2sip]

Hello,

Eto po ung mga readings:(pls refer po sa pix. Thanks)
The 3 big wires have the same reading regardless kung anong pairing ang pagsasamahin. I also tried connecting 2 wire to an outlet, and the other end to, say the RED wire.Lightly touching the other wire to both the white and blue wires produce spark. Kahit baliktarin mo pagkabitkabitin, which means there's no way this transformer is gonna be connected to AC now( see sir tony's post). Baka nashort na sa katetest ko.

On the secondary, thE two ORANGE wire have readings. Putting the probe on the GRAY wire produce reading on the RED and BLUE wire.

be suspicious of transformers taken from UPS's they could have the low voltage windings connected to the high voltage windings.......

transformers for UPS's serve a different finction, check and double check, be safe.....

Thanks for the warning sir tony. It's true. Studying the circuit board, the RED Primary is connected DIRECTLY to the + of the battery while the BLUE and WHITE go to the circuit and to the 5 or so transistor. I know zilch of electronics so I can only suspect that the torroid could have low voltage windings as sir tony warned.

Thnaks for the help guys.

[tony]

j2sip.

the reason for these is that the traffo is also used for charging, remember that the inverter mosfets have diodes built in, so charging is taking place when the normal meralco power is present.

doing the transformer in "auto-transformer" mode save a lot in terms of iron core than would otherwise be required.

[???]

Baka ganito implementation nyan. Center tap, tigkalahati para sa upper half at lower half para sa inverter mode. Ito yung nakakabit sa B+ ng battery at yung dalawang end naman ay papunta ng switching transistor para mapalusot yung DC sa transformer sa inverter mode. Alternately turning on and off.

Yun kasing iba ang ginagawa single winding lang palitan lang ng terminal para makalusot yung DC sa transformer.

Tapos yung isang terminal na nakatap sa B+ battery pero papunta sa isa na namang winding ay pwedeng low current(charging winding nya), pwedeng ang laro nito ay sa pamamagitan ng relay na nasa board.

Yung ibang wiring ay pwedeng para sa sensing circuit nya o 110VAC at tap para sa adjustment ng 220VAC.

[wenz33]

agree ako kay sir js,..
yan hobby ko gumawa ng ibat ibang design ng inverter mula sa pinaka maliit hanggang sa high power inverter,..kalimitan ginagamit jan 24v ct ung output ng transformer