| Parameter | Formula | Unit | |-----------|---------|------| | | ( E = 4.44 \cdot f \cdot N \cdot B_m \cdot A_e ) | Volts | | Turns per volt | ( TPV = \frac14.44 \cdot f \cdot B_m \cdot A_e ) | turns/V | | Primary turns | ( N_p = V_p \cdot TPV ) | – | | Secondary turns | ( N_s = V_s \cdot TPV ) (adjust for regulation) | – | | Core area (EI lamination) | ( A_e = \textstack \times \texttongue width ) | m² | | Window area | ( W_a = \textheight \times \textwidth of winding window ) | m² | | Copper area per winding | ( a_cu = I / \delta ) (δ = current density, e.g. 2.5 A/mm²) | mm² | | Wire diameter | ( d = \sqrt\frac4 \cdot a_cu\pi ) | mm | | Resistance | ( R = \frac\rho \cdot MLT \cdot Na_cu ) | Ω | | Copper loss | ( P_cu = I^2 R ) | W | | Core loss | ( P_core = \textspecific loss (W/kg) \times \textcore mass ) | W | | Regulation | ( %Reg = \fracI_p R_p \cos\theta + I_s R_s \cos\thetaV_s \times 100 ) | % | | Temperature rise | Approx. ( \Delta T = \fracP_totalA_surf \times k ) | °C |
| A | B | C | D | E | F | G | |---|---|---|---|---|---|---| | | Value | Unit | Formula | Result | Check | Status | | Core Area | 12.0 | cm² | - | - | - | - | | Flux Density | 1.2 | T | - | - | - | - | | Turns/Volt | - | - | =1/(4.44 50 B2 B1 0.0001) | 3.12 | - | - | | Pri Turns | 718 | - | =230 B4 | 718 | - | - | | Sec Turns | 37 | - | =12 B4 | 37 | - | - | | Pri Wire (mm²) | 0.21 | mm² | =VA/230/2.5 | 0.21 | SWG=25 | OK | | Window Fill | 38% | % | =Copper_area/Window_area | 0.38 | <0.4 | OK | transformer design calculation excel
The heart of the transformer is the magnetic core. In the Excel environment, the core design begins with the fundamental equation relating voltage, turns, flux density, and core area. In the Excel environment, the core design begins
where B2=Vp, B4=f, B5=Bmax, B3=Ae.
Attached is the excel spreadsheet that i created to design the transformer. All About Circuits All About Circuits