List of Symbols

Page numbers are those on which the corresponding symbol first appears. A symbol formed from one of the tabulated letters, with a subscript or prime added, is not listed unless it is frequently and prominently used in the book. Sometimes the same symbol denotes more than one property; the meaning is then determined by the context. Units are given wherever symbols are used. Small letters indicate instantaneous or varying electrical quantities, and capital letters indicate steady, effective, or scalar values.

a	Coil radius
a	Coil winding height
a	N2/N1
A	Area
Ac	Core area
An	Ripple amplitude
b	Winding traverse
B	Xc/R1 at frequency fr
B	Core flux density
Bm, Bmax	Maximum operating flux density
Br	Residual flux density
c	Insulation thickness
c	Specific heat
C	Capacitance
C1, Cp	Primary capacitance
C2, Cs	Secondary capacitance
Ce	Effective capacitance
Cg	Capacitance of winding to ground
Cw	Capacitance across winding
d	Core tongue width
d	Toroid diameter
D	Winding height
D	Xc/R2 at frequency fr
e	Voltage (instantaneous value)
eg	Alternating grid voltage
ep	Alternating plate voltage
E	Emissivity
E	Voltage (effective value)
EB	Plate voltage
E0	Output voltage
E1	Primary voltage
E2	Secondary voltage
ES	Secondary no-load voltage
EL	Secondary full-load voltage
Epk	Peak value of alternating voltage
Edc	D-c voltage
Ea	Voltage at top of pulse
f	Frequency
fm	Midband frequency
fr	Resonance frequency
fc	Cut-off frequency
f( )	Function of
F	Factor
gm	Mutual conductance
G	Gap loss constant
H	Magnetizing force
Hc	Coercive force
i	Current (instantaneous value)
I, |I|, Irms	Current (effective value)
Idc	Direct component of current
Ipk	Peak value of current
Iav	Average value of current
Ip, Ib	Plate current (d-c)
IL	Load current
IE	Loss component of exciting current
IM	Magnetizing current
IN	Exciting current
IG	Grid current (d-c)
j	sqrt(-1) (vector operator)
J	Low-frequency permeability/pulse permeability
k	Thermal conductivity
k	Coefficient of coupling
k	1/2 ratio of impedance/circuit resistance = sqrt(L/C)/2R
K	Constant
lc	Mean length of core (or magnetic path)
lg	Air gap
L	Inductance
Le	Open-circuit inductance (OCL).
Ls	Short-circuit inductance
Lm	Mutual inductance
m	Decrement
m	Order of harmonic
M	Modulation factor
MT	Mean turn length
n	Number (e.g., of anodes)
N	Turns
N1	Primary turns
N2	Secondary turns
NL	Number of layers (of wire in coil)
OCL	Open-circuit inductance
p	Density
p	Ratio of voltages (in autotransformer)
p	Rectifier ripple frequency/line frequency (number of phases)
Pa	Volt-amperes per pound
Pc	Core loss
PA	Ripple amplitude/Edc (in rectifier)
PR	Ripple amplitude/Edc (across load)
PFN	Pulse forming network
PRF	Pulse repetition frequency
Q	ωL/R = coil reactance/coil a-c resistance
r	Radius
re	Equivalent radius
rp	Plate resistance
R	Resistance
R1	Source resistance
R2	Load resistance
RL	Load resistance
Re	Equivalent core-loss (shunt) resistance
S	Secondary winding
S	Core window width
t	Time (independent variable)
t	Thickness of insulation
T	Period of a wave
T	2πsqrt(LsC2) (undamped period of oscillatory wave)
V	Commutation voltage
V	Volume (of core)
w	Core-stacking dimension
Wg	Gap loss
We	Core loss
Ws	copper loss
X	Reactance
XN	Open-circuit reactance = 2πfLe
XC	Capacitive reactance = 1/(2πfC)
XI	Inductive reactance = 2πfL
Z	Impedance
ZG	Source impedance
ZL,	Load impedance
Z0	Characteristic impedance
α	Amplifier gain
α	sqrt(CgCw)
α	Damping factor
ω	Feedback constant
ω	Natural angular frequency
δ	Small interval of time
Δ	Increment (e.g., of flux)
Δ	Exciting current/load current
ε	Base of natural logarithms (= 2.718)
ε	Dielectric constant of insulation
η	Efficiency
θ	Temperature
θ	Phase angle
μ	Amplification factor
μ	Permeability
μΔ	Incremental permeability
π	3.14159
φ	Phase angle
φ	Flux (varying)
φmax	Peak value of flux
Σ	Summation (of a series of elements)
τ	Pulse duration
ω	2πf (angular frequency)