Ag. Tech- Exam 3

- Tractors and Agricultural Equipment (GIS & GPS -PTT [10/13]) - Building and Structure Basis - Baics of Fencing

PPT - ELECTRICAL PRINCIPLES AND WIRING MATERIALS

PPT - ELECTRICAL PRINCIPLES AND WIRING MATERIALS

Electricity

form of energy that can produce: light, heat , magnetism & chemical changes

Resistance

material prevent electrical flow

Conductor

allows electricity to flow easily

Insulator

material that proides great resistance

rate of flow of electricity in a conductor

amperes (AMP)

Volt or Voltage

measure of electrical pressure

!!!!!!!!!!!!

• emf- electrical motor force is another word for

!!!!!!!!!!!!

amps- rate of flow

volt- electrical pressure

watt- amount of worl

ohms- resistance

Watts

measure of the amount of energy or work that can be done

OHMS

measure of electrical resistance to flow

OHMS Law

• states that the direct current flowing through a conductor between two points is direclty proportional to the potential difference across the two points

• requires one volt to push one amp of current through one ohm of resistance in a DC circuit

• proportion that shows how voltage (V) current (I) and resistance (R) are related in a circuit

  • as long as you know 2 values, you can come up with the third one

  • V = 1 x R

  • I = V

  • R= V

• Ohm = R

• Volts = E

• Amps = I

• Ohm’s Law: E=IR

• I = E/R

• R=E/I

GFCI

ground fault circuit interupter

Service entrance does what?

supplies power from power company

Service entrance terms(?)

• transformer- drops volts from 25,000 volts to 240 volts

• service drop- wires from transformer to house

• entrance head- weather proof at house

• service entrance panel (SEP)- box with fuses or breakers

INTRODUCTION TO ELECTIRICTY- PPT

INTRODUCTION TO ELECTIRICTY- PPT

!!!!!!!!!!!!!!!

Rate of electrical flow (volume of
electricity flowing)
Rate at which electrical current is
measured
Usually referred to as “amps”

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Kilowatt = 1000 watts

“does anybody know what this is, its a flat iron - dose any one use flatiorns any more?”

!!!!!!!!!!!!!!! kilowatt hour is very similar to what?

gasoline sold by the gallon

Electricity is sold by what?

Kilowatt hour

how many watts equal one horsepower?

746

West Virginia Formula

Watts= Volts x Amps

• Amount of work that can be done in a circuit is equal to the voltage in the circuit (x’s) the amps

• 10 × 1,000 = 1,000 W

• 240 V

• Amps»>

• W=VxA

• A= W / v

• = 4.2 amps

!!!!!!!!!!!!!!!

pressure would be = voltage (force)

Circuit

controlled path for electricity to flow beginning at the source (usually a breaker), traveling to the consumer (ex.light) and back to the source

National Electric Code (NEC)

set of guidelines for use when designing and installing electrical service and devices

American Wire Gauge (AWG)

standard size of water

Parallel Circuit

Most common type of circuit, has more than one way that electricity can flow

!!!!!!!!!!!!!!! example of a series circuit

christmas lights

Series Circuit

has only one pathway for electricity to follow. If there is more than one device in the circuit, the electricity must flow through one device before it can move to the next

CIRCUITS AND DEVICES- PPT

CIRCUITS AND DEVICES- PPT

Branch circuit

circuit that beings at the breaker box and goes to a usable device, such as a outlet

GIS & MIS - PPT

GIS & MIS - PPT

Georgraphic Information Systems (GIS)

computerized systems developed for capturing, storing, checking and displaying various posiitons on the earth’s surface

GIS Storing

processo of organizing collected geographic data and storing it for future evaluation and use within GIS

GIS Checking

process of utilizing existing geographic information within a GIS to analyze land for use

GIS displaying

retrieving info from GIS and viewing on a digtal or print medium

Data Capture

process of putting or storing information into the GIS

Projection

method utilized for transfering information from three dimensional surfaces to maps or display screens

Global Positioning Systmes (GPS)

systems which utilize a global network of satellites to locate positions anywhere on the earth’s surface

Satellites

create a network known as the GPS Constellation and control the aerial views of Earth at a distance of approximately 11,000 nautical miles

Control System

operated by the United States Military, with the primary base in Colorado and four more locations around the world

3 catgeories of civilian use of GPS

• navigation (most prevelant)

• surveying

• mapping

How is GPS technology used in argiculture?

large scale farming and cattle operations

• farmers use

  • GIS - chart location of pest infestation

  • GPD- target the area with pesticide

What is thaverage distance of high voltage transmission lines?

300 miles

Where does the term electricity come from

the greek term ‘elektron’ which means ‘amber’

the technology for electric cranes dates back to-

1830s, first developeb by robert anderson, a scottish inventor

How fast does electricty travel?-

speed of light, 186,000 miles per second

Italian physicist Alessandro voltro in 199..

who invented the electric battery?

SMALL ENGINE BASISCS- PPT

SMALL ENGINE BASISCS- PPT

Examples of small engines

Chainsaws, lawn mowers, weed eaters, four wheelers, wood splitters, garden tillers

what are the two types of small gasoline engines that are common today?

four cycle & two cycle

how does a four cycle engine operate?

on a series of four “strokes” or piston movements

how does a piston operate?

in an up and down, or back and forth motion within a cylinder

cylinder

Cranckshaft

the piston is connected to a crankshaft that converts the up and down motion to a rotatry motion, which powers the implement

Crankcase

The crankshaft extends through the _______ which is attached to a flywheel at one end and a blade, gear, transmission orblade, gear, transmission or pulley at the other end

capped with a thick plate called a head, which seals the cylidner

cylinder head

Two types of valves

• intake (larger)

• exhaust

Intake Valve

lets the fuel mixture into the combustion chamber

exhaust valve

lets exhaust fumes out

!!!! Four stroke engine/ four stroke cycle

engine operates on a series of four “strokes” or piston movements

reciprocating

traveldown or side to side

part of the engine that operates the valves by a crankshart

camshaft

Carburetor

provides the air/ fuel mixture to the engine

Spark Plug

ignition in the combustion chamber occurs in the form of an electrical spark

Where does the spark of the spark plug come from?

process known as electrical induction

Four stroke engine, moving parts are lubricated by what?

motor oil

Oil sump

where oil is located in the bottom of the crankcase in most small engines

Cylinder block (INFO IMAGE)

(INFO IMAGE)

Crankshaft (INFO IMAGE)

Piston (INFO IMAGE)

Piston Rings (INFO IMAGE)

(INFO IMAGE)

(INFO IMAGE)

AG TECH LAB 10-6-23

AG TECH LAB 10-6-23

Engines- produces own power

• Motors - external power source

• 4 stroke cycle - 98%

  • 2 stroke- dirty emissions (oil and gas mix)

  • Stihl » 50:1 ratio

  • Poulan » 40:1 and 30:1

• same basic parts

  • main part - Engine Block

    • does not rotate or reprocate

  • piston(s) - rite inside cylinder(s) [RECIPROCATING]

  • rings (normally 3)- top, middle and bottom [RECIPROATING]

  • connecting rod(s)

  • Crank shaft [ROTATES]

  • Camshaft- controls valve timing [ROTATES]

  • Valves - (2) Intake, Exhaust, …..tappet (lifters)….springs (retaingers)[ RECIPROCATING]

  • Carbonator - (fuel injection)

    • Air/ Fuel Mix (15:1 ratio)

    • air filter

  • Exhaust- Muffler

Engines

produces own power

motors

external power source

98% of all engines today are what?

4 stroke cycle

Stihl

a german manufacturer of chainsaws and other handheld power equipment including trimmers and blowers

FOUR STROKE ENGINE-OVERVIEW - PPT

FOUR STROKE ENGINE-OVERVIEW - PPT

Four stroke engines

convert chemical energy to mechanical energy

crankshaft then converts _____?______movement on the piston to rotary motion, using a journal which is offset to the crankshaft centerline

reciprocating

a four stroke cycle of operation requires four strokes of the piston inside the cylinder which involves

two full rotations of the crankshaft

for every 2 rotations that the crankshaft does,

its 180 degree rotation per stroke

ICPE

customer premise equipemnt

Intake Stroke

process of obtaining fuel and air required for combustion

• begin with the intake valve open and exaust valve closed

Compression Stroke

when the air/ fuel mixture becomes compressed in the cylinder

• intake and exhaust valves reamin closed

what does BDC stand for?

bottom dead center

Intake Stroke Image

Image

What kind of stroke is this image illustrating?

Compression stroke

Power (Combustion) stroke

when the compressed air/ fuel mixture is ignited by a spark plug

• intake and exhaust valves remain closed

what is this an image of?

Power combustion stroke

Exhaust Stroke

process of releasing the spent air/ fuel mixture

• camshaft open the exhaust valve

what is this an image of?

Exhaust stroke