Presentation on theme: "Have Fun Teaching Electrical Jim Halderman. Introduction Former flat-rate technician Former automotive college instructor Author of many automotive textbooks."— Presentation transcript:
Voltage Testing DC Volts is the most commonly used A “V” with a straight line above it. AC volts is a V with a wavy line on top
Series Demonstration A typical nine-volt battery contains six 1.5 volt AAAA batteries connected in series. The voltage adds would connected in series (1.5 X 6= 9 Volts) Students will never forget this
Dry Cell Battery Drop Test Good battery- stays up or bounces once Discharged battery- bounces several times Does not always work Use a voltmeter
Measure body resistance Gets students to use the meter Should them the Ohms symbol Show them where to place the test leads How much is normal?
Need to measure k-Ohms Normal body resistance is 200k to 400k Ohms If lower means dehydrated Can be over one million so they will measure 1.1 Meg Ohms which really confuses them
What the meter reading means Think of MONEY! 1.00 = a dollar 0.50= fifty cents or a half dollar 0.25 = quarter 0.01 = a penny Milliamps I compare to thousandth of an inch such as bearing clearance. 0.020 amp is like 20 thousandth of an inch
Protect the meter Fuse the meter lead Saves money because the expensive internal fuse will be protected. Use a 10 A. Fuse Tie a knot in the leads- keeps them from getting tangled
Project Based Learning The first week, students get a meter. We use the meter every day starting with checking their body resistance. Asked to purchase some low cost electrical parts that they can use to build projects for their project grade
Speaker Tester Uses a 1.5 volt battery Connect to the speaker terminals If positive (+) is to the positive terminal, the speaker cone moves away for the coil
Air Bag Diagnostic Tool Use a 2Ω ½ watt resistor as “load tool” to replace a module Most modules measure 1.5 to 3.5 Ohms
Shorting Bars When an air bag module is disconnected, spring-loaded shorting bars short the two terminals together Use stir straw to cover one of the shorting bars
Lighter Plug Tester Uses a double banana plug Terminals are ¾ inch apart-the same for all meters Lighter plug Some wire
Lighter Plug Tester Usage Domestic vehicles- Lighter (power)plug is “hot” at all times Import brands- Controlled through the ignition
Using the lighter Plug-#1 Battery Testing- Connect and watch voltmeter and turn on high beam headlights. Watch voltage drop After it stabilizes, turn off the lights Watch how fast the voltage increases The final voltage is the SOC.
Using the lighter Plug-#2 Cranking voltage- Crank the engine Observe the battery voltage Should be above 9.6 Volts during cranking
Using the lighter Plug-#3 Charging Voltage- Start the engine and observe the voltmeter Should be 13.5-15.0 Volts
Using the lighter Plug-#4 AC Ripple Voltage- Start the engine Turn on the headlights to provide an electrical load Switch meter to read AC volts Should be less than 0.5 Volt
Diodes I do not wait to get to the electronics part of the course to teach diodes Most students can easily understand a diode
LEDs Red Green Blue Anode (+) Cathode (-) “A” comes before “C” so the anode is the positive and the cathode is the negative
LED Test Light One LED One 470Ω ½ W resistor A clicker style pen Some wire etc.
Memory Saver Very popular Can be used with a 9- Volt battery Can be connected to a jump box
OBD II DLC Memory Saver Use OBD II male connector…Pin #4(-) and #16(+) to lighter plug and to a jump box
Theft Deterrent Very popular Many students build this and install on their own vehicle Easy to build How does it work?
Logic Probe Use to check for power and ground A test light can only detect power (unless connected to power)
Parts List PROJECT #1 (Air Bag load tool) 2 ohm resistor and label One stir stick straw PROJECT #2 (Speaker tester) Battery holder PROJECT #3 (Lighter plug test tool) Double banana plug Lighter plug (male end with wire) – need to cut and strip wire Two black cable ties Pocket screwdriver PROJECT #4 (LED test light) LED 470 ohm resistor-1/2 Watt Two stripped wires 1 wire nut PROJECT #5 (Logic probe) One red LED One green LED Two-470 ohm resistors Three stripped wires 3 wire nuts
Electrical parts suppliers that I use www.amazon.com www.vetco.net www.meci.com (Mendelsons) www.meci.com www.parts-express.com www.radioshack.com
Summary Students love hands-on activities I try to get their hands on meters as soon as possible I give them projects that they can make using low-cost parts. Projects that are useful Have fun teaching electrical
Contact Information Jim@jameshalderman.com For a copy of this presentation go to: www.jameshalderman.com Click on “Jim’s Stuff” Click on “Conference Power Points”
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