You’ve been issued a multimeter for this course.
It can do so much more than just measuring V, I, R.
I will share with you two additional things you can do with your multimeter that will be useful for this course, as well as for EG1311 and the other modules you take that require a multimeter.
Continuity Testing
Your multimeter has a function that can test if a circuit is open or closed.
Switch your multimeter to the dial with the ‘Volume’ symbol. Refer to the blue circled portion of the image. Don’t worry if your multimeter looks different, most if not all multimeters have this function.
To use this, simply connect the prongs to the portion of the circuit you wish to check is closed or open.
If the circuit is CLOSED: multimeter will continuously beep.
Else, the circuit is OPEN: no noise, meaning the component being tested has an open circuit somewhere.
Use cases
This is very useful for debugging circuits.
If your circuit is 100% correct but just doesn’t work, it could be the case that the connecting wires have broken on the inside (hence, open circuit).
This would normally be impossible to debug, but since you now know how to do a continuity test, you can just connect a potentially faulty wire (or component) across the probes and listen for (the absence of) a beep. No need to waste time reconnecting every component bit by bit to see where it breaks!
This is especially useful for CG1111A/CG2111A/CG2271/… and EG1311 where hardware faults may tend to be wire breakage.
Fuse testing
This second function extends the function I described earlier.
If your multimeter can’t measure current or behaves wonky, chances are that its fuse has blown.
To check if the fuse of a suspicious multimeter has broken, use an unbroken multimeter and switch it to the beeping mode. Connect the unbroken multimeter to the multimeter you want to test. If it beeps, the suspicious multimeter is WORKING. If not, then the fuse of the multimeter has blown.
Now that you learned how to do a continuity test with a multimeter, you should be able to debug much faster and self-diagnose fuse issues!