ELECTRICAL COMPONENTS and CIRCUITS

1
ELECTRICAL COMPONENTS and CIRCUITS

• Instrumental Analysis II
• CTEC 1345

2
Introduction

• Electrical terms and types of circuits will be
  covered in this section.

3
Agenda

• Current
• Voltage
• Resistance
• Power
• Energy
• Ohms Law
• Series and Parallel Circuits

4
ELECTRICAL CHARGE  

• coulomb 6.24 x 1018 electrons

5
CURRENT

• Current is the flow of
• electrons (I) and is measured
• in amperes (A)

6
CURRENT

• Ampere number of e- passing a given point in
  one second
• 1 amp 1 coulomb/sec
• An ammeter measures current

7
VOLTAGE

• Voltage is the difference of potential energy
  that forces electrons (current) to flow in a
  circuit.

8
VOLTAGE

• Voltage is proportional to the difference in
  electrical energy between two points.

9
VOLTAGE

• Voltage is measured in
• volts (v)
• One volt is required to force 1 amp through 1 ohm
  of resistance.
• A voltmeter measures voltage.

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RESISTANCE

• Resistance is the opposition to the flow of
  electrons (current).

11
RESISTANCE

• Resistance is measured in ohms (W)

12
RESISTANCE

• Resistance is due in part to the nucleus of each
  atom resisting the removal of their electrons and
  the collision of the electrons with each other
  during flow.

13
RESISTANCE

• An ohmmeter measures resistance.

14
POWER

• Electrical power (P)
• the amount of electrical energy converted to
  another form of energy in a given length of time.

15
POWER

• Electrical power is measured in watts.

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POWER

• P VI
• P power
• V voltage
• I amperes

17
ENERGY

• When electrons are in motion they have kinetic
  energy.

18
ENERGY

• Electrical energy is measured in joules.

19
ENERGY

• E VIT
• E energy
• V voltage
• I amperes
• T time

20
ENERGY

• An example of everyday use of electrical energy
  is the kilowatt hour. 

21
ENERGY

• Power can be substituted for VI in the formula
  and divided by 1000 to convert to kilowatts.
• E Pt/1000

22
ELECTRICAL CIRCUITS

• All electrical circuits contain the following
  three parts
• voltage source
• load (resistance)
• conductors for current

23
OHM'S LAW

• V IR
• V voltage I
  amperes R resistance

24
SERIES CIRCUIT
25
SERIES CIRCUIT

• current ( IT ) remains the same throughout the
  entire circuit.

26
SERIES CIRCUIT
The total voltage (VT) is calculated from Ohms
Law using the total resistance (RT) and the total
current (IT) of the series circuit.

• VT IT RT

27
SERIES CIRCUIT

• In a series circuit with more than one load

28
SERIES CIRCUIT

• the total resistance ( RT ) is the sum of the
  individual resistances.

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SERIES CIRCUIT

• RT R1 R2 . . . .

30
SERIES CIRCUIT

• the total voltage ( VT )is the sum of the
  individual voltages across each load.

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SERIES CIRCUIT

• VT V1 V2 . . . .
• V1 R1 (IT) R1 (I1)

32
SERIES CIRCUIT

• VT V1 V2 . . . .
• V1 R1 (IT) R1 (I1)

33
PARALLEL CIRCUIT

• A parallel circuit consists of individual series
  circuits

attached to the same voltage source.
34
PARALLEL CIRCUIT

• The current through an individual series circuit
  may be different than the current flowing through
  the other series circuits.

35
PARALLEL CIRCUIT
The total current (IT) is the sum of the
individual currents flowing through each series
circuit.

• IT I1 I2 . . . .

36
PARALLEL CIRCUIT

• The voltage across each series circuit is the
  same.

VT V1 V2 . . . .
37
PARALLEL CIRCUIT

• The total resistance (RT) of the parallel circuit
  is less than the total resistance of any
  individual series circuit.

38
PARALLEL CIRCUIT
39
PARALLEL CIRCUIT

• The individual currents in a parallel circuit are
  calculated the same as in a series circuit.