Transcript + Z

Learning in
Electronic Circuits
Reading Schematics
© 2013 Universitat Politècnica de Catalunya (EPSEVG)
José Antonio Soria Pérez - Collaborative Professor at the EPSEVG (UPC).
C/ V. Balaguer, 1. Vilanova i la G. (Barcelona - Spain). Telf: +34 93 896 77 27 Fax: +34 93 896 77 00
Office hours: VG3-D101 – EEL MON 10-14h, TUE: 10-14h (Yellow zone)
E-mail: [email protected], [email protected]
In this lesson you will learn...

... to read schematics



Definition of the different parts of a schematic
Designation of components
Annotation of electrical variables, magnitudes and units
José Antonio Soria Pérez
Departament d’Enginyeria Electrònica
Universitat Politècnica de Catalunya
2/11
The elements of “schematics”
The “schematics“ represents the connection of components in a circuit

This point is a junction with
4 connected wires
This is a junction
3
A Specific branch
Upper branch
1
2
Right branch

A junction is any connecting point between two (or more) components
A branch is any open path containing two or more junctions.
A mesh is any closed path (clockwise convention) containing three (or more) junctions
Middle branch

Left branch

This point is a crossing of
2 unconnected wires
Lower branch
In this schematic,
the 7 components
areon
connected
with 6 junctions
possibilities
depending
chosen components
This Several
schematic
has 3 meshes
José Antonio Soria Pérez
Departament d’Enginyeria Electrònica
Universitat Politècnica de Catalunya
3/11
The elements of “schematics”


The “schematics“ represents the connection of components in a circuit
A component consists of a symbol and a designator

Components
are generally annotated from left-to-right and up-to-bottom
Example:
A
resistor
Passive:
Rn
Resistors
Semiconductor:
+
Uppercase letter specifies component class
specifies
component number (...of the
Z2 Subscript
Zfor
5 Resistor)
(‘R’ stands
Capacitors
Inductor
Transformer
class in thevalue
diagram)
(value) same
Component
(when inserted)
(i.e. 1kΩ)
Typical Designation References
Atenuator of Z
LS = Loud
speaker
This isATT
the
symbol
a1 resistor
= Trimmer number specifying
In=semiconductors
and integrated
circuits,
this label isTR
a reference
Z
Z7
4
BR = Bridge rectifier
M = Motor
TP
=
Test point
manufacturer information
...and
this
its
designator
BTT = Battery
MK = Microphone
U = Integrated circuit
Bipolar
Diodes
MOSFETs
Z3 Potentiometer Z6 JFET V = Vaccum tube
C = Capacitor
P=
Transistors
Example:
A
Zenner
diode
Active:
D = Diode (inc. Zeener, etc…)
PS = Power supply
X= Transducer
DS = Display +
Q= Transistor +
Y = Crystal
or (oscillator)
+
+
F = Fuse
R = resistor
RT = Thermistor
1
J = Jack Connector
RT = Thermistor
Manufacturer’s
reference number
JP = Jumper
S = Switch
(B); Zenner
diode (Z); Breakdown
voltage 4.7 Volts
DC Voltage
DC/AC Silicum
Current
AC Voltage
Variable controlled
K = Relay
T = Transformer
L = Inductor
TC = Termocouple
D
BZ4V7
José Antonio Soria Pérez
Departament d’Enginyeria Electrònica
Universitat Politècnica de Catalunya
4/11
The elements of “schematics”



The “schematics“ represents the connection of components in a circuit
A component consists of a symbol and a designator
Electricity is generated by connecting external (or independent) sources
Sources can be either Voltage (V) or Current (I) …

... and can be either Direct Current (static) or Alternate Current (dynamic)
Z1
Z4 and dynamic behaviour

Uppercase and lowercase symbols
specify static
Voltage
source
A DC voltage
source specifies the nature
Current
source
An AC voltage

In sources,
the subscript
of external
energysource

+
_
I
VCC
VCC +
VCC
VCC
(12V)
_
Uppercase
symbol
V+
+
vcc(t)
Z
CC.- Power supply 3
IN.- Input
Z2 source
t
G.- Generator
ICCZ
(1A)
Lowercase
symbol
6
Z5
t
In “active”
sources, electric current normally flows
Uppercase symbols
generally
Lowercase symbols generally
from
their
POSITIVE
pole
to
their
NEGATIVE
pole
Current
and
flow
direction
fixed
to the
Voltage and
DC
polarity
values
do
fixed
not
to
vary
the
circuit
with
the
time
AC
values
vary
with the
timecircuit
denote constant parameters
denote
incremental
parameters
(Convention: Current outgoing from the positive pole) (Convention: Positive pole set by flow direction)
José Antonio Soria Pérez
Departament d’Enginyeria Electrònica
Universitat Politècnica de Catalunya
5/11
Annotation of electric signals

The following notations are used both in DC and AC signals


Electrical variables always in italic.
Metric prefixes and main electrical units
Total component (lowercase symbol, uppercase subscript)
Vectors are indicated in bold
Incremental (or AC) quantities (both Vlowercase)
→ [Volts] → V
iC(t) aka. iC
ic(t1)
iC(t1)
Ic
I → [Ampers] → A
Peak valueP → [Watts] → W
E → [Joule] → J
R → [Ohms] → Ω
C → [Farad] → F
L → [Henry] → H
IC –Direct (or DC) quantities (both uppercase)
t - time
José Antonio Soria Pérez
Departament d’Enginyeria Electrònica
Universitat Politècnica de Catalunya
6/11
The elements of “schematics”




The “schematics“ represents the connection of components in a circuit
A component consists of a symbol and a designator
Electricity is generated by connecting external (or independent) sources
Electric current flows through the circuit branches and causes voltage
drops to appear “across” junctions.


Convention with electric current always entering the positive pole
i-v relationship established by component operation and electrical laws
Z1
IZ1
+
IZ4
_
VZ1
*V +
CC
_
IZ3
+
_
VZ2
_
IZ6 = IZ4
V
I
Z4
The
circuit behaviour
using 𝑉
+
+
+ theme of obtaining
𝑅=
“electric laws” is addressed in the next lesson:
𝐼
VZ6
Z3
Z6
VZ3
V
The Ohm’s Law
_ Analysis
Lesson
2:
Circuit
Z5
_
_
Z2
Example: The Resistor
Z4
IZ2
+
José Antonio Soria Pérez
Departament d’Enginyeria Electrònica
_
VZ5
+ I =I
Z5
Z4
The Ohm’s law is the most basic form of electric
law (i-v relationtionship) in circuit analysis
Universitat Politècnica de Catalunya
7/11
Components, Variables and Annotation rules





The “schematics“ represents the connection of components in a circuit
A component consists of a symbol and a designator
Electricity is generated by connecting external (or independent) sources
Electric current flows through the circuit branches and causes voltage
drops to appear “across” junctions.
Circuit operation is seen as an Input /Output relation
Electronic circuits (or “systems”) carry out operations with electric signals

”Ways”
Input
of of representing the input and output of a circuit
Electronic

Z1
the system
Is the initial signal to be
processed by the circuit +
vs(t)
It can be any
External Source
Source/Load
Arrow
Dot
Full representation
notation
notation
José Antonio Soria Pérez
Departament d’Enginyeria Electrònica
Z3
Vin
_
Z2
System
Z4
+
Z5
Output of
the system
+
Is any electric variable
providing the result
Vout
ZL
_
Universitat Politècnica de Catalunya
To get the result we
often use a load (L)
(another circuit device
or component)
8/11
Components, Variables and Annotation rules






The “schematics“ represents the connection of components in a circuit
A component consists of a symbol and a designator
Electricity is generated by connecting external (or independent) sources
Electric current flows through the circuit branches and causes voltage
drops to appear “across” junctions.
Circuit operation is seen as an Input /Output relation
The Ground is a reference point (typ. 0V) for other voltages in the circuit

Z
Z4
Other1ground reference
symbols:
+
Unipolar +
Differential
Input & output
Vin
_
Z3
Z2
Earth
Ground
Vout
Z5
_
+
Z4
+
Generally (but
These are
Vinnot necessarily) assigned
Z3
equivalent
to negative poles in input sources
Vout
circuits
Signal
Generic
Chassis
Ground
Ground
Ground
ZL
Voltages refferred to Voltages
(negativenot
pole
connected
to)
refferred
todepending
ground
are
A
variety
of
definitions
terminal
groundGround
are known
asdifferential
unipolar voltages
(or floating) voltages
José Antonio Soria Pérez
Departament d’Enginyeria Electrònica
Z1
_
ZL
_
on the true physical connection
Universitat Politècnica de Catalunya
9/11
1st. Exercise

Annotate the following circuit:

Place the ground connection and specify designators and electric variables (indicating
voltage positive and negative poles, and electric current flow direction). Specify the total
number of junctions and possible meshes of the circuit.

Solution:
1 IR2 R2
I1
IR1
+
V1
41

3 junctions
6 meshes
José Antonio Soria Pérez
Departament d’Enginyeria Electrònica
+
R1
_
3

+
VR1
I2
2
_
VR2
6
2
IR3
+
VR3
R3
_
+
35
V2
3
These are, in fact,
the same junction
Universitat Politècnica de Catalunya
10/11
2nd. Exercise

Annotate the circuit

Complete the annotation just as in the preceding example specifying junctions and
meshes (Note: Be aware of both AC and DC components)

Solution:
R2
iR2
+
+
iR5
_
_
vR2
vR4
V1
+
iR3 R3
+
vR1
+
iR1
R1
R4
iR4
_
vR3
i2
+
R5
vR5
_
+
v2
_


5 junctions
8 meshes
José Antonio Soria Pérez
Departament d’Enginyeria Electrònica
Universitat Politècnica de Catalunya
11/11