Electronic Technician Certification Program

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Electronic Technician Certification Program

Electronic Technician Certification Program Electronic Technician Certification Program

DC Fundamentals

January 23, 2021

1/20/2022 [email protected] 1

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Electronic Technician Certification Program

Electronic Technician Certification Program DC Fundamentals

January 26, 2021

V-peak

V-peak-peak

t(1msec) 0.5 1.0

T =Period (complete 1 cycle)

AC signal

• Signal name: Sine-wave

• Time domain: amplitude varies with time

• V_p = V_peak = 5 V

• V_p-p= V_peak-peak = 2 x V_p= 10 V

• V_RMS( effective voltage) = 0.707 X Vpk=3.535V

• T = Period ( in second )

• F = Frequency ( in hertz )

• Relationship between Period and Frequency:

• T = 1 / F

^or

F = 1 / T

( T=sec F=Hertz )

Cycle - One complete occurrence of a repeating wave (periodic signal) such as one positive and one negative alternation of a sine wave.

Frequency - the number of cycles of a signal that occur in one second.

Period - the time distance between two similar points on a periodic wave.

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Electronic Technician Certification Program

DC Fundamentals

January 23, 2021

• To handle with the large number in electronic systems used power of ten notation

• The number 10 is called the base and its power is called the exponent

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Electronic Technician Certification Program

Electronic Technician Certification Program DC Fundamentals

January 23, 2021

EXAMPLE

Answer:

a) 2.484 b) 4.91 x 10³

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Electronic Technician Certification Program

DC Fundamentals

January 23, 2021

EXAMPLE

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Electronic Technician Certification Program

Electronic Technician Certification Program DC Fundamentals

January 23, 2021

EXAMPLE

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Electronic Technician Certification Program

DC Fundamentals

January 23, 2021

1. Convert 0.1 MV to kilovolts (kV). =0.1 x 10^3 =100kV 2. Express the following in engineering notation:

a. 10 x 10⁴ volts = 100X10^3

b. 0.1 x 10³watts= 0.1kW c. 250 x 10⁷ seconds= 2500X10^6 EXAMPLE

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Electronic Technician Certification Program

Electronic Technician Certification Program DC Fundamentals

January 23, 2021

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Electronic Technician Certification Program

DC Fundamentals

January 23, 2021

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Electronic Technician Certification Program

Electronic Technician Certification Program DC Fundamentals

January 24, 2021

Structure of a molded carbon composition resister

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Electronic Technician Certification Program

DC Fundamentals

January 24, 2021

Actual size of carbon resistors (2 W, 1 W, 1 ⁄2 W, 1 ⁄4 W, 1 ⁄8 W).

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Electronic Technician Certification Program

Electronic Technician Certification Program DC Fundamentals

January 24, 2021

Power resistors.

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Electronic Technician Certification Program

DC Fundamentals

January 24, 2021

Integrated resistor network

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Electronic Technician Certification Program

Electronic Technician Certification Program DC Fundamentals

January 24, 2021

External view of variable resistors

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Electronic Technician Certification Program

DC Fundamentals

January 24, 2021

RESISTOR COLOR CODE

Opposite to the current flow

General purpose Resistor 4-bands

Precision Resistor

5-bands

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Electronic Technician Certification Program

GENERAL PURPOSE RESISTOR COLOR CODE

First band Second band Third band Fourth band

Color First Digit Second Digit Multiplier Tolerance

Black - 0 10

⁰

-

Brown 1 1 10

¹

-

Red 2 2 10

²

-

Orange 3 3 10

³

-

Yellow 4 4 10

⁴

-

Green 5 5 10

⁵

-

Blue 6 6 10

⁶

-

Violet 7 7 10

⁷

-

Gray 8 8 10

⁸

-

White 9 9 10

⁹

-

Gold - - 10

^-1

+/-5%

Silver - - 10

^-2

+/-10%

None - - - +/-20%

DC Fundamentals

June 14, 2021

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Electronic Technician Certification Program

PRECISION RESISTOR COLOR CODE

Color First Second Third Multiplier Tolerance

Digit Digit Digit

Black - 0 0 10

⁰

-

Brown 1 1 1 10

¹

+/-1%

Red 2 2 2 10

²

+/-2%

Orange 3 3 3 10

³

-

Yellow 4 4 4 10

⁴

-

Green 5 5 5 10

⁵

+/-0.5%

Blue 6 6 6 10

⁶

+/-0.25%

Violet 7 7 7 10

⁷

+/0.1%

Gray 8 8 8 10

⁸

-

White 9 9 9 10

⁹

-

Gold - - - 10

^-1

-

Silver - - - 10

^-2

-

DC Fundamentals

February 02, 2021

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Electronic Technician Certification Program

Electronic Technician Certification Program DC Fundamentals

January 24, 2021 EXAMPLE

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Electronic Technician Certification Program

DC Fundamentals

January 24, 2021

EXAMPLE

Answer Brown, Black, Violet, Gold EXAMPLE

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Electronic Technician Certification Program

Electronic Technician Certification Program DC Fundamentals

January 24, 2021

Conductance

Conductance, G, is defined as the measure of a material’s ability to allow the flow of charge and is assigned the SI unit the siemens (S). A large conductance indicates that a material is able to conduct current well, whereas a low value of conductance indicates that a material does not readily permit the flow of charge. Mathematically, conductance is defined as the reciprocal of resistance. Thus

G = 1/ R

unit is [siemens, S] Where R is resistance in OHM

Determine the conductance of the following resistors:

a. 5 

b. b. 100 k

EXAMPLE

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Electronic Technician Certification Program

DC Fundamentals

January 24, 2021

Ohm’s Law

• The relation between Apply voltage E and the current I and resistor R

• E = I x R

Where E= apply voltage in volts I= current in Ampere

R= resistance in ohms

• I = E / R

• R = E / I

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Electronic Technician Certification Program DC Fundamentals

January 24, 2021

Power is in Watt

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DC Fundamentals

January 24, 2021

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Electronic Technician Certification Program

Electronic Technician Certification Program DC Fundamentals

January 24, 2021 A B

D C

DC Series Circuit

• Current is the same through each resistor

• Voltage across each resistor is different

• Power dissipated by each resistor is different

• Total resistance of the circuit:

Rtotal = R1 + R2 + R3 + … Rn

• Voltage across resistor R1: VR1=VAB=VA-VB = I x R1

• Voltage across resistor R2: VR2=VBC=VB-VC = I x R2

• Voltage across resistor R3: VR3=VCD=VC-VD = I x R3

• Total voltage E = VR1 + VR2 + VR3

• Power dissipated PR1 = I²x R1

• Total power Ptotal = E x I = PR1 + PR2 + PR3

5. VR3 = _________ V

6. Power PR1 = _______Watt 7. Power PR2 = _______Watt 8. Power PR3 = _______Watt For the circuit shown, solve for:

1. Total resistance Rtotal= _______  2. Total current I = ________A

3. VR1 = ________ V 4. VR2 = ________ V

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Electronic Technician Certification Program

1/20/2022

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DC Fundamentals

January 24, 2021

The Voltage Divider Rule

( Apply to Serial circuit only )

To calculate the voltage from B to the Ground same as

voltage across R2 we can calculate current I then VR2=I x R2 Using the voltage Divider rule as following

VR2 = E x R2/( R1 + R2 )

A B

c

For the circuit shown with R1,R2,R3,R4 Use the voltage divider rule, calculate:

1. Voltage at point b 2. Voltage at point c 3. Voltage at point a

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Electronic Technician Certification Program

Electronic Technician Certification Program DC Fundamentals

January 24, 2021

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Electronic Technician Certification Program

DC Fundamentals

January 24, 2021

PARALLEL Circuit or Shunt circuit

• All the resistors connected in the parallel will have the same voltage E = VR1 = VR2 = VR_N

• The current through each resistor ( branches current ) in parallel are different

• The total current I_T= I1 + I2 + I_N

• The total resistance ( R_T ) or Equivalent resistance calculate as the following

• For only two resistors in parallel

• R_Tcalculate as R_T = ( R1 x R2 ) / (R1 + R2)

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Electronic Technician Certification Program

Electronic Technician Certification Program DC Fundamentals

January 24, 2021

EXAMPLE

R

_T

Calculate the total resistance for the circuit

shown. R_T = ___3____

R

_T

EXAMPLE

shown. R_T = ___8____

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Electronic Technician Certification Program

DC Fundamentals

January 24, 2021

EXAMPLE

shown. R_T = ___50____

EXAMPLE

shown. R_T = _______k

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Electronic Technician Certification Program

Electronic Technician Certification Program DC Fundamentals

January 24, 2021

Parallel Circuit

Apply for only two resistors in parallel CURRENT DIVIDER Law

IT

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Electronic Technician Certification Program

DC Fundamentals

January 24, 2021

For the circuit shown, determine the following quantities:

a. RT b. IT

c. Power delivered by the voltage source d. I1 and I2 using the current divider rule e. Power dissipated by the resistors

EXAMPLE

Solution

a. RT = R1 R 2 / R2 R2 = 1.6 k b. IT =E / RT = 22.5 mA

c. PT = E X IT = 810 mW

d. I2 = R1 / ( R1 + R2) x IT = 4.5 mA e. I1 =R2 / ( R1 + R2 ) X IT = 18.0mW f. PR1 = E² / R1 = 648mW

g. PR2 = E² / R2 = 162mW

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Electronic Technician Certification Program

Electronic Technician Certification Program DC Fundamentals

January 29, 2021

A B

B A

C

GND

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Electronic Technician Certification Program

TEST EQUIPMENTS:

• DMM ( Digital Multimeter ) Measure:

• DC and AC (Vrms) voltages

• DC and AC (Irms) currents

• Resistance (Ohm)

• Continuing Option:

• Capacitance

• Diode

• Frequency

To measure current HI Lead must connect to this site

DC Fundamentals

January 29, 2021

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Electronic Technician Certification Program

Electronic Technician Certification Program DC Fundamentals

January 29, 2021

Use DMM to measure DC and AC voltages:

• To measure voltage at point C ( single point )

• Connect DMM-HI (Red Lead ) to C

• Connect DMM-LO (Black Lead ) to GND (common)

• To measure voltage across R2 (from C to D)

• That means voltage from point C to D and VCD =VC-VD

• Connect DMM-HI (Red Lead ) to C

• Connect DMM-LO (Black Lead ) to D

• Use DMM to measure the AC voltage or AC current,

• Only voltage you can get is V_RMS and I_RMS not Vpk-pk or Ipk-pk

• To measure the current either DC or AC you must break the circuit, this is not practical happen in the company