Well First day of "charging systems" practical we disassembled an alternator, learnings the innards of how it works. Learning to identify the parts like the rotor, electromagnet, regulator, rectifier, brushes, slip rings etc.
So the alternator works by having electrical energy pass through its contacts turning on the electromagnet and while the rotor inside is run off a belt connected to an engines crank pulley, it gets turned over multiple times rapidly producing an AC current which is then converted to DC current by the alternators rectifier and the output is then controlled by the regulator to not overcharge or overproduce power......to briefly rundown the just of it.
After learning about the innards and how it does its job, the next day we took our newfound knowledge to the real deal...an engine.
Although it was a turn-key on a test bench it was just like the real thing except without the headlights, brakes and all the other fruit on a car.
To start things off we had to do our safety check and safety rundown (rundown being engine instructions etc). Steeltoe boots were check, overalls and open ears check.. i was set to start the first set of instructions.
First we checked if the brakes were on and that it was in neutral before we started our tests. The damned thing was bolted down to a testbench so i doubted it was gunna go anywhere.
Next, preliminary checks were made, charge warning light working-yes, accessories off-yes, visual inspection of the wiring-wiring good, alternator mounting-strong and checking the fusable links-good.
Belt drive inspection, belt in good nick (new), tensioned correctly.
Now we had to do a no load test on the alternator.
First checking the batterys OCV: 12.75v
Regulator voltage spec: 13.5-14.5v
Regulated reading: 14.08v
Amp output for carb'd engines.
Checking the Amp output: 8.8
these test was a text book pass.
Then a load test was required next...
Charge voltage under load-specs: OCV+0.5v= 13.8
The clamp induction meter and a multi meter were needed for the next set of tests.
multi meter is set to 20v DC, clamp induction meter set to 400Amp DC then zero it.
Place the clamp around the B+ cable from the alternator, take the engines rev's to 2000, turn on car accessories besides the wipers and radio.
Now after that i took a clamp meter reading. '
Output Amps reading: 8.1Amps
Charging voltage under load 61.5Amps
Another test pass.
Lastly was the voltage drop tests. Specs at 0.20-0.40v drop only.
To get a fairly accurate reading there needs to be a fair bit of load. So with the engine running with all the accessories on (except the wipers and radio) Using a mutimeter i checked the drop between the battery positive and alternator output. 0.1v
Volt drop between battery negative and alternator body while engine is still running: 0v
Added volt drop total: 0.1v
These tests were a pass.
Charging systems Q&A.
1.
Q1-1 :A stator is a group of stationary conductors, directed in right angles to the rotating magnetic field or rotor.
2: The rotor turns and its magnetic field jumps across to the stators conductors, introducing current into the stators conductors.
Q2-1:A rotor is a rotating electro magnet.
2:The function of the rotor is to rotate and create and eletromagnetic current when combined with the stator, creating AC current.
Q3:The function of the retifier is to convert the AC current into DC current to power the cars accessories and other eletronics.
Q4-1:Delta connection
2: Y-connection.
Q5-1:Delta diode has more amps at low alternator RPM's
2: Y-Diode has more amps at a higher RPM.
Q6:
Q7:
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