Operating a Amp – Volt – Ohm Meter Created for CVCA Physics By Dick Heckathorn 3 April 2K

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3 Wiring a House p 123 WH 3

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Comments Supplies Needed - Black wire, green wire - Battery and battery holder way switchs 2 3-way switchs - 4 Christmas tree bulbs Provided -wire stripper -Awl or ice pick -Electric meters - battery tester 10

Using a Digital Multi Meter 132? 133 ? 11

Function Range Switch Common Jack 2 V, Ω, mA Jack 3 10 A Jack 4 1 always use 12

DC Volts 1 AC Volts 2 Resistance 3 DC Amps 4 5 Diode 13

A.Main Control and Input Ports The first task when using a meter is to determine what is to be measured. The second task is to plug the red and black leads into the meter. 14

The black lead is plugged into the Common Jack. For measuring current (I) the red lead is plugged into the 10A. If you are measuring voltage (V), or resistance (ohms), the red lead is plugged into the V, Ω, mA Jack. A.Main Control and Input Ports Common Jack 15

There is a fuse inside the meter to protect it when measuring current. A.Main Control and Input Ports 16

B.To Measure D.C. Current The Function Range Switch is moved to the DC Amps (DCA) region. There are four separate settings within this region. They are: 2000 µ (0.002 A), 20 m (0.02 A), 200 m (0.2 A) and 10A. These values represent the maximum reading that can be measured when the switch is set on that setting. DCADCA 17

To Measure D.C. Current To protect the meter when measuring DC current, the Function Range Switch is set to the maximum value setting before the final connection that activates the meter In this case it would be the 10 A setting. (Red lead inserted into 10 A Jack.) We will use this terminal whenever current is made. 18

To Measure D.C. Voltage The Function Range Switch is moved to the DC Volts (DCV) region. There are five separate settings within this region. They are: 1000 (V), 200 (V), 20 (V), 2000m (2 V) and 200m (0.2 V). DCV 19

To Measure D.C. Voltage The Function Range Switch is first set to the highest reading 1000 before the final connection that activates the meter. Once the meter is active, the Function Range Switch is rotated to the next lower setting until a reading is seen in the window. The voltmeter is connected in parallel across the component being measured. 20

To Measure D.C. Voltage Thus the complete circuit is created before the meter is connected. 21

To Measure Resistance The Ω region measures the resistance of an object. There are five separate regions: 2000 K (2,000,000 ohms), 200 K (200,000 ohms), 20 K (20,000 ohms), 2000 ohms and 200 ohms. Ω 22

To Measure Resistance When measuring resistance there is no danger of damaging the meter so set it to any setting. Connect the meter leads, one to each end of a resistor. Then move the FRS until a reading is seen on the screen. Then record it When the reading is determined, rotate the meter dial to off. 23

Measuring Continuity The ♫ will be used to determine if there is continuity (a complete path in a component). A buzzer will buzz if there is continuity in the component being tested. ♫ 24

The A.C. Volt region will not be used as the power source will be DC batteries. 25

Harbor Freight Tools 26

Using the meter as an Ammeter to Measure DC Current 27

Measuring DC Current 1. Connect one wire of a Christmas tree bulb to a 1.5 volt battery. Connect the other wire of the bulb to one terminal of the ammeter. A 28

Measuring DC Current Set the Function Range Switch to the 10A setting in the DCA region with red lead plugged into the 10 A Jack. Finally connect the terminal of the ammeter to the battery. A 29

Measuring DC Current The bulb should light. A current reading should be seen in the meter window. A 30

Measuring DC Current 2.Record the reading in the window with the unit of the dial setting. I = _____________amps A 31

A Measuring DC Current 3.Reverse the terminals of the meter. Anything different? Record your findings. 32

Measuring DC Current 4.Disconnect one of the wires from the battery. Next turn the meter off. Then disconnect the meter wires. A 33

Using the meter as a Voltmeter to Measure DC Voltage 34

Measuring DC Voltage 1.Connect the bulb to the battery. ………… 35

Measuring DC Voltage 2.Rotate the dial to the 2000 m (2 V) on the DCV Range 36

Measuring DC Voltage 3.Connect the leads of the meter across the region you wish to know the voltage. V 37

V Measuring DC Voltage 3.Connect the leads of the meter across the region you wish to know the voltage. 38

Measuring DC Voltage 5.Reduce the DC-Volt setting step-by- step until a reading is obtained. 6.Record the reading. 7.Remove meter from the circuit 8.Rotate the meter dial to off. 8.Disconnect one of the wires from the battery. 39

V Measure the voltage of the battery. DON’T DO IT !!!! Voltmeter connected in SERIES NO! 40

Measuring the Health of a Battery 3.The circuit shown below shows the voltmeter connected in parallel across the battery and thus will give a proper reading in volts of the condition of the battery. V 41

Measuring the Health of a Battery 4.This connection also shows the condition of the battery. 5.Can you see why this is true? V 42

Here we see an ammeter and a voltmeter connect in the circuit. 43

Day Thurs April 5 44

1.Kilo-Watt Assignment Questions 2.The Electron Leak Article 3.Hand out meters 45

Voltage meter key Ampere meter key Watt and VA meter key AC Power Outlet Receptacle Timer function for KWH meter Engineering Unit of meter reading KWH meter and Timer key Frequency and Power Factor key Meter Function 46

3.Cary – Your electrical question 4.Wire a house schematic discussion 5. 47

Battery Tester Here we see a battery tester measuring a AAA battery. This meter will report the condition as: ok (green), weak (yellow) or in poor condition (red). Note the battery tested is ok. 48

Battery Tester Here we see a 9-volt battery ready to be tested. The meter shown can measure 1.5 volt batteries as D-cells, AA-cells and AAA-cells as well as 9 volt batteries. There is an opening in the bottom where button batteries can be measured. 49

Electrical Information Charge (Q) Energy (E) Resistance (R) Potential Difference (V) Current (I) Power (P) 50

Electrical Information We purchase electricity in units of kilowatt-hr This says we are purchasing electrical energy. 51

1. Cary - Electrical Problem 52

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Homework Kill-O-Watt Meter The Electron Leak Article Continue with Activity where leave off today. 62

Further Investigation 1. Construct a circuit that has two light bulbs in series connected to a battery. Include a meter in the circuit that will be used to measure the current. 63

2.How did you construct the circuit? a.Now set the meter dial. b. Finally complete the circuit. 64 A R1R1 R2R2

65 3.Measure and record the current. I = ____________ A R1R1 R2R2 65

66 4.Measure and record the voltage across the battery and both of the bulbs. A R1R1 R2R2 VBVB V1V1 V2V2 V B = _______ V 1 = _______ V 2 = _______ 66

67 4.How does V B compare to V 1 and V 2 ? 5.What conclusion can you come to? 67

That’s all folks! 68

The 10 A Jack is used when the current will be greater than 0.2 amp. A.Main Control and Input Ports Always start with the red lead in the 10 A Jack when making any current measurement. 10 A Jack 69

As this is a cheap meter it must be rotated to the correct setting within the region. FRS always set to off unless a measurement is being made. Then turned off when done. The third task is to rotate the Function Range Switch to the appropriate region. A.Main Control and Input Ports DCVDCV ACV DCADCA Ω 70

The third task is to rotate the Function Range Switch to the appropriate region. The fourth task is to connect the meter and make measurements. A.Main Control and Input Ports Function Range Switch FRS always set to off 71