Capacitors
In this task we had to wire up a capacitor with a resistor in series.
A capacitor stores electrical charge , it provents voltage spikes from happening.
A capacitor stores electrical charge , it provents voltage spikes from happening.
Tuesday, April 5, 2011
Relays
A relay is the component which uses a low amps in a circuit to switch on a greater amp circuit.We measured resistance of the relay from
86 to 85 was 69.8 ohm
30 to 87a was 0.2 ohm
30 to 87 was infinity (∞)
When the relay is off 30 to 87a is Normally Closed and 30 to 87 is Normally Open
Resistors
RESISTORS
We had to choose 6 type of resisitors, then using the resistor colour band and using the chart bellow we found out the resistance of the resistors in Ohm's(Ω), and checking the resistors tolerance, then using a multimeter to check that the calculations we did were correct . Then we took two resistors and wired them into series to meausure the total resistance of the resistors in series, then we wired them up into parallel to and measure the resistance and the total resistance should be lower than the lowest resistance because more consumers are added into a parallel cicuit and the resistance goes down and the current goes up, but in the series circuit they only have one path to follow because they go through all the resistors creating higher resistance making less current flow.
Thursday, March 24, 2011
Alternators
A alternator charges the battery, it converts the alternating current to direct current without it our battery would die out .
Then we did a Rotor winding internal resistance test , we set the multi meter to 200 Ω and placed each lead on a slip ring the spec was 2 Ω to 6 Ω my reading was 2.8 Ω which was a pass.
Next we did a stator winding resistance test , we set the multi meter on 200 Ω , then we found the common terminal (one with the most wires) and placed the black lead , while the red lead on each terminal the spec was 0.0 Ω to .2 Ω and i got 0.1 Ω for all my terminals which was a pass because there was no short circuit or loose connections in the wires.
Later we set the meter to 2k and placed the red lead to the common stator winding terminal (one with the most wires) and placed the black lead to the body of the alternator the spec was Infinity ∞ and my reading was infinity ∞ which was a pass , because there was no circut between the stator winding and ground if there was a circuit the stator has grounded and requires replacing.
We set the meter on diode test mode , to test the rectifier positive diodes first we place the positive lead to the B terminal which is that brown peice in the picture to the right , and the black lead to the P terminals were the screws go.
The resistance should be high
The spec was 0.5vd to 0.7vd
All of my terminals were a pass because they were .561vd
Part Number : M3S 12600-1580
Feild Setting : ''A''
Voltage : 12v
Set Point Spec : 14.3
A voltage regulator controls the alternators output by increasing and decreasing the strength of the rotors magnetic field.
Then we Checked the brush protusion length , minimum length was 4mm and my brush lengths were 6mm which was a pass because they were over the minimum length , if they were below 4mm it would need to be replaced.The brushes supply electricity to the slip rings and if they are too short the brushes can't apply enough pressure to maintain a good contact.
Charging system On-car Testing
We did a test on a Subaru Impreza WRX 2009 , it was very easy to locate the alternater because it was right infront.
The belts were in good condition and all the conncetions were tight.
Next we tested the batter and was 12.7v wich was good , we tested it by setting the multi meter to 20DC volts and placed the positive to positive and negative to earth.
Next we testeted the regulator , the spec was 13.5-14.9 my reading was 14.5 and was a pass . we put the multi meter to 20v DC and turned the car on and place the red lead to positive and black lead to negative on the battery.
Then we did a no load test , the spec was 10-18 amps , my reading was 12.7 amps which was a pass , first we got the amp meter clamp then clamped it around the positive wire and reved the car to 2000 .
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| Alternator |
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| Alternator Bits |
First we removed the rear cover off the alternator , then we did a test on the rotor shaft and slip ring below with the multi meter , we set it to 2k and we had a reading of infinity (∞) wich was a pass because the spec was ∞ infinity.
This was a rotor winding to ground test.
This was a rotor winding to ground test.
Next we did a stator winding resistance test , we set the multi meter on 200 Ω , then we found the common terminal (one with the most wires) and placed the black lead , while the red lead on each terminal the spec was 0.0 Ω to .2 Ω and i got 0.1 Ω for all my terminals which was a pass because there was no short circuit or loose connections in the wires.
Later we set the meter to 2k and placed the red lead to the common stator winding terminal (one with the most wires) and placed the black lead to the body of the alternator the spec was Infinity ∞ and my reading was infinity ∞ which was a pass , because there was no circut between the stator winding and ground if there was a circuit the stator has grounded and requires replacing.
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| Rectifier |
We set the meter on diode test mode , to test the rectifier positive diodes first we place the positive lead to the B terminal which is that brown peice in the picture to the right , and the black lead to the P terminals were the screws go.
The resistance should be high
The spec was 0.5vd to 0.7vd
All of my terminals were a pass because they were .561vd
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| Regulator |
Part Number : M3S 12600-1580
Feild Setting : ''A''
Voltage : 12v
Set Point Spec : 14.3
A voltage regulator controls the alternators output by increasing and decreasing the strength of the rotors magnetic field.
Then we Checked the brush protusion length , minimum length was 4mm and my brush lengths were 6mm which was a pass because they were over the minimum length , if they were below 4mm it would need to be replaced.The brushes supply electricity to the slip rings and if they are too short the brushes can't apply enough pressure to maintain a good contact.
We did a test on a Subaru Impreza WRX 2009 , it was very easy to locate the alternater because it was right infront.
The belts were in good condition and all the conncetions were tight.
Next we tested the batter and was 12.7v wich was good , we tested it by setting the multi meter to 20DC volts and placed the positive to positive and negative to earth.
Next we testeted the regulator , the spec was 13.5-14.9 my reading was 14.5 and was a pass . we put the multi meter to 20v DC and turned the car on and place the red lead to positive and black lead to negative on the battery.
Then we did a no load test , the spec was 10-18 amps , my reading was 12.7 amps which was a pass , first we got the amp meter clamp then clamped it around the positive wire and reved the car to 2000 .
Wednesday, March 23, 2011
Starter Motor
The Starter motor is a component which turns the engine of a car over.
The Starter motor has the following components in it :
1. Armature
2. Feild Coil / Pole Shoe
3. Housing
4. Brushes
5. Bushes
6. Starter Drive
There are 3 Type of Starters :
1.Inertia
2.Pre-Enage
3.Gear Reduction
Ground Circut test :
Ground Short Circut between each of the commutor segments and the Armature core or shaft .
Should read 1. (infinity)
Testing Commutator :
Measuring the Commutator diameter and checking the mica undercut dept.
Checking Armature Shaft for run out :
To check for run-out, Place the armature between the ''V'' Blocks.
Turn the armature 360 while reading the dail test indicater set up onto the armator core as in the picture.
Testing for Internal short circuts using growler :1. Place the armature on the ''V'' of the growler.
2. Turn on the growler position
3.Hold a hacksaw blade or a metal strip along the armature and rotate the armature
Hacksaw blade will vibrate when placed over shorted winding indicating a shorted armature
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| Starter Motor |
The Starter motor has the following components in it :
1. Armature
2. Feild Coil / Pole Shoe
3. Housing
4. Brushes
5. Bushes
6. Starter Drive
There are 3 Type of Starters :
1.Inertia
2.Pre-Enage
3.Gear Reduction
 |
| Starter Motor In Bits |
Ground Short Circut between each of the commutor segments and the Armature core or shaft .
Should read 1. (infinity)
Measuring the Commutator diameter and checking the mica undercut dept.
To check for run-out, Place the armature between the ''V'' Blocks.
Turn the armature 360 while reading the dail test indicater set up onto the armator core as in the picture.
Testing for Internal short circuts using growler :1. Place the armature on the ''V'' of the growler.2. Turn on the growler position
3.Hold a hacksaw blade or a metal strip along the armature and rotate the armature
Hacksaw blade will vibrate when placed over shorted winding indicating a shorted armature
Battery Testing
Inspecting for Batter Specifications
Make of Battery : Lucas
Battery Number : 127MF
Battery capacity in Cold Cranking Ams (CCA) : 550
Type : Conventional
To use a electrolyte simply unscrew the caps of
Voltage | State of charge |
12.60v+ | 100% |
12.50v | 75% |
12.40v | 50% |
12.30v | 25% |
12.20v | 10% |
Battery Testing On A Vechile
Vechile type : Sudan
Name of Battery : Lucas
Battery Number : 2794
CCA: 310
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| Example |
Tuesday, March 22, 2011
Electricity Circuts
Electricity Circuts : Individual, Series, Parallel and Series - Parallel
Voltage: The force that moves the electrons in a circuit.
Series CircuitIn a seires curcuit electricity flows one way through all the components.The components use the same amount of volts and if one bulb stops all of them will stop working. There are less amps in a series circuit
Paralellel Circuits
In a parallel circuit each component has there own power supply and earth , therefore if one stops working the rest will keep going they all get the same amount of volts and in series there is less voltage because they share it
Ampere (Amps): Is the measure of current ,the higher the current in a circuit the more reading you will get.
Ohms: Is the unit of resistance. This slows down the flow of electrons.
Wattage: The measure of power that is being used.
Voltage drop: To show us how much voltage is being used up by each component in a circuit.
Available Voltage: This shows us how much voltage is available to work Voltage drop: To show us how much voltage is being used up by each component in a circuit.
Individual Circuts
Individual circuits are a simple circuit, It had one light going, Only one path for the electricity to flow through. The power supply was set to 12.74v.We learnt how to use a multimeter to read the available voltage voltage drop ,Amps but to measure amps the circuit needs to be broken at a point where the multimeter can be attached to the circuit so the current flows through it.To work out resistance the circuit needed to be turned
Series CircuitIn a seires curcuit electricity flows one way through all the components.The components use the same amount of volts and if one bulb stops all of them will stop working. There are less amps in a series circuitParalellel Circuits
In a parallel circuit each component has there own power supply and earth , therefore if one stops working the rest will keep going they all get the same amount of volts and in series there is less voltage because they share it
Sunday, March 20, 2011
Logic Probe
Logic Probe
The Tester is only for 24volts or less .
List of Parts :Brass Rod 150mm Long
Red LED
Green LED
Black wire
Red Wire
2 Resistors 1k Ω
Red Alligator clip
Black Alligator clip
100mm Plastic Tube
And some Shrink tubing
Very simple and easy to make ,first we solded a resistor to each led then solded them to a long peice of wire , later we put heat shrink over the the resistor and spreaded the legs of the LED apart.
Then we get the brass rod and tined the middle with some solder , later we placed heat shrink on the side to insulate the brass rod.
We then solded the LED's to the tinned area of the brass rod , also we put some glue to give the LED's more support and took the wires to one side of the Brass rod , then placed heat shrink over it .
We then solded the LED's to the tinned area of the brass rod , also we put some glue to give the LED's more support and took the wires to one side of the Brass rod , then placed heat shrink over it .
Finally onto the last steps , we get a plastic support tube and cut the one end as long as both leds and abit more then placed in were the wires come from like in the picture below.
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