MAGNETIC FLUX
MAGNETIC FLUX
MAGNETIC FORCE
MAGNETIC POWER
REACTANCE
TEMPERATURE
INDUCTANCE
RELUCTANCE
SKINDEPTH
QiCoil
LITZE
Magnetic Flux (B Gauss or Tesla)
Inductance
uH
Current
Amp
Ae = Area
cm2
Turns
N
Magnetic Flux
Gauss
Magnetic Flux
Tesla
Magnetic Flux (B Gauss or Tesla)
Npri
turns
Ae Area of core
cm2
Switch-Frequency
kHz
Vin
Volt
Bmax
Tesla
Magnetic Force (H (Oe or A/cm))
Current
Amp
Turns
N
le
cm
Magnetic Force
Oersted
Magnetic Force
A/cm
Frequency Calculator
Input Voltage
Volts
Inductor
µH
Peak Switch Current
Amps
Duty Cycle
%
Required Switching Frequency
kHz
Estimated Power output
Watts
Output Power Calculator
Input Voltage
Volts
Inductor
µH
Duty Cycle
%
Expected Efficiency
%
Frequency
kHz
Output Power
Watts
Peak Inductor Current
Amps
Iripple calculator
Volt In
Volts
Volt-Out
Volts
Frequency
Hz
Inductance
H
I-ripple
A
Inductance Calculator
Input Voltage
Volts
Frequency
kHz
Duty Cycle
%
Peak Inductor Current
Amps
Inductance
µH
Estimated Power output
Watts
Ad Soetens:
Inductive reactance is defined as:(10-4)XL=_ωL=2πfLwhere XL is the inductive reactance, ω is the angular frequency, f is the frequency in Hertz, and L is the inductance.
Calculating Inductive Reactance and /
Current
High frequncy noise filtering
Xl
k
Ω
>
Ω
Freq.
kHz
>
Hz
Henry
L
mH
<
µH
@
60
Hz
Xl =
Ω
L
mH
>
Henry
Freq
Hz
>
Hz
Freq
kHz
>
Hz
Voltage
V
Reactance Solution Xl
Xl
Ω
@
Hz
Xl
Ω
@
Hz
Solution I
I
A
@
I
A
@
Temperature calculation from Resistance increase:
Temp coefficient α (copper)
Reference Resistance
Start of Test
Reference Temperature
Resistance at temperature T
End of Test
Temperature T
⁰c
Temp coefficient α (copper) Table
0 ⁰c
20 °c
Matthiessen's temperature coeflBcient, 0° C to 20° C
0,00398
0,00369
Laboratoire Central d'Electricite
0,00400
0,00370
Kennelly and Fessenden, 1890
0,00406
0,00375
American Institute of Electrical Engineers
0,00420
0,00387
Verband Deutscher Elektrotechniker
0,00426
0,00392
(British) Institution of Electrical Engineers
0,00428
0,00394
Lagarde, 1893
0,00445
0,00409
Wheeler Formula (Single Layer Air Inductor)
Least Accurate!
Number of Turns (N)
(N)
Thickness (d)
mm
Mean Radius
mm
Coil Length (l)
mm
Inductance =
uH
L =
0.0315 x N^2 x R^2
(6 x R) + (9 x l) + (10 x d)
uH
Wheeler Formula (Single Layer Air Inductor)
Most Accurate
Number of Turns (N)
(N)
Relative Permeability (μr)
Mean Radius (R)
mm
Coil Length (l)
mm
Inductance =
uH
L =
μ x π x N^2 x R^2
l ( 1 + 0.4502(2R/l))
Henrys
Solid core inductor AL vs Inductance
inductance per turn
Number of Turns (N)
Turns
Al
nH/T2
Inductance =
uH
Reluctance Model Classic
Parameter
Value
Unit
Initial permeability
μi
L
uH
N
Turns
Ae
mm
2
le
mm
μ
0
gap
mm
Parameter
Value
Unit
Initial permeability μi
μi
gap
mm
Ie
mm
N
Turns
Ae
Meter2
μ
0
L
uH
Calculation of skin depth and R
ac
for a cylindrical conductor
Enter frequency [MHz]:
kHz
Hz
Enter diameter of conductor [mm]:
Enter length of conductor [mm]:
Enter μ
r
of the conductor:
Enter ρ/ρ
c
for the conductor:
Material :
Aluminium
Copper
Gold
Silver
Skin depth 1 is:
mm
Skin depth 2 is:
mm
(no account for ρ and μ)
RF current area is:
mm
2
Lambda [m]:
R
ac
is:
Ohm
(no account for ρ and μ)
R
ac
is:
Ohm
(Alternative equation 1)
R
ac
is:
Ohm
(Alternative equation 2)
R
dc
is:
Ohm
Resistivity,ρ [ohm-m]:
Permeability, μ [H/m]:
Conductor area is:
mm
2
DATA
ρ x 10^-8
μ
Aluminium
2,6548
1,00002
Copper
1,678
0,999991
Gold
2,24
1
Silver
1,586
0,99998
Qi Coil Capacitor Calculator
Equations from Qi Standard
Frequency (khz)
Frequency (hz)
100
100000
fs
1000
fd
Coil
Free Space Inductance (uH)
Tolerance (%)
Min Inductance (H)
Max Inductance (H)
DC Resistance (ohm)
C
s
C
s
Value Min (F)
C
S
Value Min (nF)
C
s
Value Max (F)
C
s
Value Max (nF)
C
d
C
d
Value Min (F)
C
d
Value Min (nF)
C
d
Value Max (F)
C
d
Value Max (nF)
Q Factor (Must be greater than 77!)
Q Factor Min
Q Factor Max
https://www.mouser.com/pdfdocs/IDT_AN816-LC-Calc_APN_20180612.pdf
https://www.mouser.com/pdfDocs/TI-Designing-a-Qi-compliant-receiver-coil.pdf
https://lup.lub.lu.se/luur/download?func=downloadFile&recordOId=9018746&fileOId=9019409
https://www.wirelesspowerconsortium.com/knowledge-base/magnetic-induction-technology/further-reading/further-reading.html
LITZ WIRES calculator
Wire Diameter d
No. strands
Packin Factor Kpf
0,01
0,014
0,018
0,02
0,032
0,034
0,036
0,038
0,04
0,043
0,045
0,048
0,05
0,053
0,056
0,06
0,063
0,067
0,071
0,075
0,08
0,085
0,09
0,095
0,1
0,106
0,112
0,118
0,125
0,132
0,14
0,15
0,16
0,17
0,18
0,19
0,2
0,212
0,224
0,236
0,25
0,26
0,265
0,28
0,29
0,3
0,315
0,335
0,35
0,355
0,37
0,375
0,4
0,425
0,45
0,475
0,5
0,53
0,55
0,56
0,6
0,63
0,65
0,67
0,7
0,71
0,75
0,8
0,85
0,9
0,95
1
1,06
1,12
1,18
1,25
1,32
1,4
1,5
1,6
1,7
1,8
1,9
2
2,12
2,24
2,36
2,5
2,65
2,8
3
3,15
3,35
3,55
3,75
4
4,25
4,5
4,75
5
3 through 12
16
20
25 through 400
Wire Diameter D
Factor
OD of litze wire
Source elektrisola
https://www.elektrisola.com/en-us/Litz-Wire/Info#litz-wire-types