Hello everyone,
I want to rewind a large iron/steel transformer.
It has 'E I' plates that measure 5.5 x 4.5 x 2.5 inches.
It has a 4 to 1 ratio [2" - 0.5"] spacing on the "E".
The old windings are coated copper ribbon 1/16 inch thick,
essentially solid copper bar with no resistance.
I want 50 v - 0 - 50 v [100v center tapped] on a 120vac primary.
What wire size and turns-length would I need?
Thank you kindly.
This very simplyfied formula work for me about 20 years...
The iron core carry about 870VA (A=29.5qcm)
Turns of primary 155 (1/16inch, enough for 7.5A)
Turns of secondary 2x71 (center tapped) 1/16 inch
Thank you Sebi,
I am painting my house and cannot find any of my electronics books.
A search on the internet gave me too much information.
I hate to throw away such a large transformer
Your experience was just what I needed.
Dave [mosfet]
try this formula. i'm using this for almost 10 years.
Example: Core Size = 1 ¼ X ¾
Formula 1:
Convert first into decimal:
thickness X center tapped = Core Area
1.25 X .75 = 0.9375 (Core Area)
Formula 2:
Compute power watts:
Power=Core Area (5.58 ) 2
0.9375 (5.58 ) =(5.23125) 2
Power =27.365977 Watts
Formula 3:
Compute number of turns:
Turn / Volts = 5.775 / Core Area
5.775 / 0.9375 = 6.16 Turn over volts
Primary winding:
6.16 X 220 Volts = 1,355 Turns
Secondary winding:
6.16 X 6 Volts = 37 + 37 turns for full wave design
6.16 X 6 volts = 37 turns for haft ware design
Formula 4:
Compute for Primary & Secondary Current:
Current = Power / Volts (I= P/V)
For primary current:
I = 27.365977 / 220 Volts = 0.124308 Amp.
For secondary current:
I = 27.365977 / 6 Volts = 4.5609962 Amp. For haft wave design
I = 27.365977 / 6 Volts = 4.5609962 / 2 = 2.2804981 Amp. For full wave design
Formula 5:
Compute for Circular Miles AWG:
Current X 680 or 700 recommended 680 for normal heat
For primary winding:
0.124308 (680) = 84.59 Cir. Mil.
AWG # = 31
(Please refer the nearest value to AWG standard table)
For secondary winding:
2.2804981 (680) = 1551 Cir. Mil.
AWG # = 18
(Please refer the nearest value to AWG standard table)
Hi.
i want to wind center taped ferrite core transformer. my requirement is 12-0-12vac and out put 220vac.kind tell me formula i.e no. of turns for primery winding,no. of turns for seconday winding. area of core and thickness of wire to be used.
Hi
Please send formula to built up a step uptransformer center taped 12-0-12 out put 220 for inverter. please send formula :
no. primary turns
no. of secondary turns
core area
Thats all the bulshit above, never ever transformer will work on these configurations or calculation.The turn ratio was totally wrong.Attaching a excel sheet for calculation but let me tell you a thing it is 80 % correct OK.