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Formulas used to calculate electrical characteristics
Connecting windings in series:
- Inductance = Inductance(table) × (number of windings)2
- DCR = DCR(table) × number of windings
- Isat = (Isat(table) × 6) ÷ number of windings connected in series
- Irms = Irms(table)
Connecting windings in parallel:
- Inductance = Inductance(table)
- DCR = 1 ÷ [number of windings × (1 ÷ DCR(table))]
- Isat = (Isat(table) × 6) ÷ number of windings connected in series
- Irms = Irms(table) × number of windings
Create a 100 Watt, 1:2, half bridge forward converter transformer with center tapped secondary
Choose HPH6-2400L
Vin = 36 – 57 Vdc; Vout = 24 V, 4.2 A
Part number |
Inductance (µH) |
Percent Tolerance |
DCR max (Ω) |
Volt-time product (V-µs) |
Irms (A) |
HPH6-2400L_ |
194 |
25 |
0.03 |
131.9 |
2.9 |
Connecting primary windings in parallel:
When primary windings (Wpri) are connected in parallel, DCR decreases, Irms increases, and inductance and volt-time product remain the same.
Example: For HPH6-2400L, connect two primary windings in parallel:
- Inductance = Inductance(table) = 194 μH
- DCR = 1 ÷ [Wpri × (1 ÷ DCR(table))] = 1 ÷ [(2 × (1 ÷ 0.030]) = 0.015 Ohms
- VT = VT(table) = 131.9 V-μsec
- Irms = Irms(table) × Wpri = 2.90 × 2 = 5.8 A
Connecting secondary windings in parallel:
When secondary windings (Wsec) are connected in series, Irms remains the same, but DCR increases.
Example: For HP6-2400L, connect four secondary windings in series, creating a center tap at pins 9 and 5. For each half of the secondary:
- DCR = DCR(table) × Wsec = 0.030 × 2 = 0.060 Ohms
- Irms = Irms(table) = 2.90 A