EE PRO for TI - 89, 92 Plus
Equations - Transformers
121
Chapter 30
Transformers
The contents in this chapter is divided into two topics.
Ideal Transformer
Linear Equivalent Circuit
Variables
All variables used in this section are listed here with a brief description and units.
Variable
Description
Unit
I1
Primary current
A
I2
Secondary current
A
N1
# primary turns
unitless
N2
# secondary turns
unitless
RR1
Primary resistance
Ω
RR2
Secondary resistance
Ω
Rin
Equiv. primary resistance
Ω
Rl
Resistive part of load
Ω
V1
Primary voltage
V
V2
Secondary voltage
V
XX1
Primary reactance
Ω
XX2
Secondary reactance
Ω
Xin
Equivalent primary reactance
Ω
Xl
Reactive part of load
Ω
Zin
Primary impedance
Ω
ZL
Secondary load
Ω
30.1 Ideal Transformer
Four equations describe the properties of an ideal transformer. The first equation relates
the primary and secondary voltages V1 and V2 in terms of the primary and secondary turns
N1 and N2. The second equation shows the corresponding relationship between the
primary and secondary currents I1 and I2. In the same fashion, the third equation relates
primary and secondary power. The final equation calculates the effect of a load impedance ZL experienced at the
primary winding terminal with a primary impedance Zin