Electricity and Electronics Technology Education Dept. Bellwood-Antis Middle School Mr. Mackereth

WHAT IS ELECTRICITY? ELECTRICITY is the FLOW of ELECTRONS through a current carrying CONDUCTOR or WIRE. ELECTRICITY CAN BE MEASURED AS….. AMPERAGE (AMPS)- The electron’s RATE OF FLOW VOLTAGE (VOLTS)- The PRESSURE of the electrons POWER (WATTS)-The measure of POWER OUTPUT RESISTANCE (OHMS)- The friction in the electric wire while electricity is trying to pass through.

COMMOM ELECTRICAL TERMS: POTENTIAL ENERGY- Energy in position, or stored energy. At rest, ready to release energy KINETIC ENERGY- Energy in motion, or energy being consumed or used to do work. MATTER- Object(s) that occupy space (atom) MOLECULE- the smallest part of a compound. ATOM- The individual elements that make up compounds in our world. ALL MOLECULES ARE MADE FROM INDIVIDUAL ATOMS!

WHAT ARE SOME OF THE DIFFERENT WAYS OUR SOCIETY USES ELECTRICITY? HOUSEHOLD USES MANUFACTURING COMMUNICATION RECREATION HEALTH & MEDICAL PUBLIC LIGHTING SAFETY & SECURITY PROFESSIONAL USES TEMPERATURE CONTROLS RESEARCH / LABORATORY

COMMOM ELECTRICAL TERMS: PROTONS- A positively charged particle in an atom ELECTRONS- Negatively charged particle in an atom DIRECT CURRENT (DC)- A continuous electrical energy, usually from transformers and batteries DC electric power ALWAYS flows from positive to negative ALTERNATING CURRENT (AC)- Electricity in a wave form that pulses from + to – 60 times a second. Regular household/business electric power is AC AC electricity pulses back & forth b/w positive & negative

COMMOM ELECTRICAL TERMS: CONDUCTOR- An object that WILL allow electric current to flow through itself. (PLASTIC, RUBBER, PVC) INSULATOR - An object that WILL NOT allow electric current to flow through itself. (WATER & METALS) ELECTRICITY QUIZ #1 IS TOMORROW! INCLUDES EVERYTHING FROM PAGE 1 OF NOTES. ALSO, KNOW SOCIETY’S USES OF ELECTRICITY! BE ABLE TO DESCRIBE DIFFERENCES BETWEEN ELECTRICAL TERMS USING COMPLETE SENTENCES.

TYPES OF CIRCUITS OPEN CIRCUIT- An electric pathway that is not connected, or has a break (short) in the path. ELECTRICITY WON’T FLOW IN AN OPEN CIRCUIT A light switch in the OFF position is an OPEN circuit CLOSED CIRCUIT- An COMPLETE electrical pathway ELECTRICITY WILL FLOW IN A CLOSED CIRCUIT A light switch in the ON position is a CLOSED circuit

TYPES OF CIRCUITS SERIES CIRCUIT- A path with only ONE “HOT” WIRE. Devices in a series circuit are connected one after the other. Old Christmas lights are wired IN SERIES. PARALLEL CIRCUIT- A path containing TWO WIRES (one HOT & one NEUTRAL wire.) Each device is connected to BOTH WIRES. Homes are IN PARALLEL GROUNDED CIRCUIT- a safe circuit preventing shock Make sure you can identify the 18 different electrical symbols on your FLASH CARDS.

ELECTRICITY QUIZ #2 INCLUDES EVERYTHING FROM PAGES 1 & 2 OF YOUR NOTES. ALSO KNOW THE FIVE DIFFERENT CIRCUITS! BE ABLE TO DEFINE ALL THE TERMS & BE ABLE TO IDENTIFY ALL 18 SYMBOLS THE QUIZ IS TOMORROW!

CALCULATING ELECTRICAL VALUES Scientists discovered in the 19 th century that electricity follows the laws of physics & can be calculated using mathematical equations. KNOW THE FORMULAS BELOW: WATTS = VOLTS x AMPS (W = V x A) VOLTS = AMPS x RESISTANCE (V = A x R) If you know or are given any two of the four values, YOU CAN CALCULATE THE OTHERS!

PRACTICE PROBLEMS PROBLEM #1 Volts = 120 Amps = 3 FIND WATTS & OHMS W = V x A W =120 X 3 W = 360 V = A x R 120 = 3 X R 3 3 R = 40 PROBLEM #2 Volts = 120 Watts = 60 FIND AMPS & OHMS W = V x A 60 =120 X A A = 0.5 V = A x R 120 = 0.5 X R R = 240

PRACTICE PROBLEMS PROBLEM #3 Volts = 12Ohms = 24 FIND AMPS & WATTS V = A x R 12 = 24 X R 24 A= 0.5 W = V x A w = 12 X 0.5 W = 6 PROBLEM #4 Watts = 1200 Amps = 15 FIND VOLTS & OHMS W = V x A 1200 = V X V= 80 V = A x R 80 = 15 X R 15 R = (5.3)

HOMEWORK PROBLEM #1 Volts = 240 Amps = 3 FIND WATTS & OHMS W = V x A W =240 X 3 W = 720 V = A x R 240 = 3 X R 3 3 R = 80 PROBLEM #2 Volts = 120 Watts = 180 FIND AMPS & OHMS W = V x A 180=120 X A A = 1.5 V = A x R 120 = 1.5 X R R = 280

RESISTORS RESISTORS are man-made components that are designed to limit the flow of electricity through small circuit boards and other electronic devices. RESISTORS have a FOUR COLOR CODE that tells us the size (amount of resistance) in each resistor. COLOR BAND #1- The 1 st digit in the resistor size COLOR BAND #2- The 2 nd digit in the resistor size COLOR BAND #3- # of zeros added (multiplier) COLOR BAND #4- The TOLERANCE level allowed

PRACTICE PROBLEM 1, a resistor with REDYELLOWBROWNSILVER 2 4 add 1 zeros 10% ANSWER: 240 Ohms with a tolerance of 10% HIGH TOLERANCE # of Ohms X T% 240 Ohms X 110% Answer: 264 Ohms LOW TOLERANCE # Ohms X T% Ohms X 110% Answer: 216 Ohms

PRACTICE PROBLEM 2, a resistor with BROWNREDORANGEGOLD 1 2 add 3 zeros 5% ANSWER: 12,000 Ohms with a tolerance of 5% HIGH TOLERANCE # of Ohms X (100 + T %) 12,000 Ohms X 105% ANSWER: 12,600 Ohms LOW TOLERANCE # Ohms X (100 – T %) 12,000 Ohms X 95% Answer: 11,400 Ohms

HOMEWORK #1 is a resistor with …. RED REDORANGESILVER 2 2 add 3 zeros 10% ANSWER: 22,000 Ohms with a tolerance of 10% HIGH TOLERANCE # Ohms X (100 + T %) 22,000 Ohms X 110% ANS: 24,200 Ohms LOW TOLERANCE # Ohms X (100 - T %) 22,000 Ohms X 90% ANS: 19,800 Ohms

HOMEWORK #2 is a resistor with …. BROWNRED BROWN SILVER 1 2 add 1 zero 10% ANSWER: 120 Ohms with a tolerance of 10% HIGH TOLERANCE # Ohms X (100 + T %) 120 Ohms X 110% ANS: 132 Ohms LOW TOLERANCE # Ohms X (100 - T %) 120 Ohms X 90% ANS: 108 Ohms