Transcript DO - MacMate

ADT490
Metering Techniques
Introduction
‣ Alarms ALS390
‣ Foundation for Troubleshooting
2
Concept Review
‣ Current
‣ Voltage
3
Concept Review - Conductors
‣ Conductor resistance is American Wire Gage
4
Concept Review - Resistance
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Depends Primarily on
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‣
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Length
Cross-sectional area
Type of Material
Conductors DO have Resistance
5
Concept Review - Resistor
‣ Limit Current / Divide Voltage / Convert Energy
‣ Ohms & Watts
6
Series DC Circuits
‣ Current same / Voltage divided between Resistors
7
Series DC Circuits - Resistance
8
Kirchhoffs Voltage Law
-
9
Voltage Dividers
10
Parallel DC Circuits
‣ Voltage in each parallel branch is equal
11
Kirchhoff’s Current Law
• For each Junction: Current in = Current out
12
Resistance in Parallel
13
Resistance in Parallel - Rules
‣ RT always < value of smallest resistor
‣ If largest resistor many times smaller resistor
‣ RT approaches value of smallest resistor.
‣ If two resistors equal
‣ RT is half original resistance
14
Current Dividers
15
AC Voltage & Current
16
AC Voltage & Current
Text
17
Measuring with a Multimeter
18
Using a Voltmeter
19
Using a Voltmeter
20
Using a Voltmeter
‣ Can use a voltmeter to check a fuse - SAFER
21
AC Versus DC
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No reading
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CHECK METER
Power on circuit
22
AC Versus DC
23
Using an Ammeter
24
Using an Ammeter
25
Using an Ammeter
‣
Fuse in circuit - 0 A fuse good, ? A fuse bac
‣
Watch the meter raing
26
Measuring Resistance
‣ Voltage impacts on reading - Nonsense Reading
‣ Highest to Lowest - Lowest most accurate
27
Ohmmeter Uses
‣ Check if EOL is Capacitor - Short then Charge
‣ Determine device polarity
28
End of Presentation
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