-Paul Valery-
French critic & poet (1871 - 1945)
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hi, we meet again here. starting the class at 9 and had been given a booklet to be answered.But then, not all of us know how to answer it coz we, especially me didnt learnt bout it during our matriculation college even though we took the physics during that time. :D
alright, now i will brief it in such a simple way what En.Redzuan had thought me this morning.
RESISTOR
resistor is more typically known as a device having resistance to the passage of an electric current.
Resistors are "Passive Devices", that is they contain no source of power or amplification but only attenuate or reduce the voltage signal passing through them. This attenuation results in electrical energy being lost in the form of heat as the resistor resists the flow of electrons through it.
2 types of resistor which are :
- TH (through hole)
- SMD (surface mount device)
- Resistor is used in a circuit to oppose an electric current by producing a voltage drop between its terminals in proportion to the current.
- it works accordingly to ohm's law.
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its is easy to calculate, thats why im only posting this picture because this pic full with info that i wanna type :)
HOW TO DETERMINE THE 1ST BAND?
- at the curve of resistor or;
- the 4th-3th gap longer than 1st-2nd gap
- if the gap is evenly distributed, look at the color of band, if there's gold or silver,it indicates that its the last band.then, you know which one is the first ine is it? :)
- 5th pink band indicates thats it is high stability in resistance.
- 6th band indicates that it precise on temperature.
- if the value of Resistor is more than maximum value or less than minimum value, it means that the resistor is out from its callibration (callibration resistor is out of range in simple words!! :))
- to get the precise reading ofresistor, the tolerance (4th band) cant be neither gold nor silver but it must be either in red or brown only.
a video which might help you coz it really helps me a lot. :)
HOW TO CALCULATE THE RESISTANCE USING MULTIMETER?
Remember!
- You can only test resistance when the device you're testing is not powered. Resistance testing works by poking a little voltage into the circuit and seeing how much current flows, its perfectly safe for any component but if its powered there is already voltage in the circuit, and you will get incorrect readings.
- You can only test a resistor before it has been soldered/inserted into a circuit. If you measure it in the circuit you will also be measuring everything connected to it. In some instances this is OK but I would say that in the vast majority it is not. If you try, you will get incorrect readings and that's worse than no reading at all.
- You can make sure your meter is working well by having a 'reference resistor' to test against. A 1% 1KΩ or 10KΩ resistor is perfect! Low batteries can make your multimeter wonky.
- Resistance is non-directional, you can switch probes and the reading will be the same.
- If you have a ranging meter (as most inexpensive ones are), you'll need to keep track of what range you are in. Otherwise, you will get strange readings, like OL or similar, or you may think you're in KΩ when really you're in MΩ. This is a big problem for beginners so be careful!
Look for an ohm (Ω) symbol, if its a ranging meter there will be a bunch of subdivided modes. If its auto-ranging there will be only one.
This meter has the Ω symbol and then 7 submodes, ranging from 200Ω to 2000MΩ (wow!)
This meter has the Ω symbol and then 5 submodes, ranging from 200Ω to 2MΩ
This meter has a multi-mode (you need to press a seperate MODE button to change between capacitor sense, diode test, resistor test and continuity!) It does not, however, have any numbered submodes, as it is auto-ranging
This meter has the Ω symbol and then 7 submodes, ranging from 200Ω to 2000MΩ (wow!)
This meter has the Ω symbol and then 5 submodes, ranging from 200Ω to 2MΩ
This meter has a multi-mode (you need to press a seperate MODE button to change between capacitor sense, diode test, resistor test and continuity!) It does not, however, have any numbered submodes, as it is auto-ranging
Ranging vs. Auto-ranging
As long as it works, it doesn't matter which type you have. But auto-ranging meters are a little slower.
Compare these two videos as I measure a 1KΩ resistor with an autoranging meter:
Which takes about 4 seconds to settle on a final value, and a 10KΩ resistor with a ranging meter:
Which gets the first significant digit instantly, the second digit after 1 second and the final digit after 2.
Expensive autoranging meters, like Fluke 73s, will be super fast so it's not a big deal, but if you have a $200 meter you're probably not reading this tutorial.
Ranges will almost always be something like 200Ω, 2KΩ, 20KΩ, 200KΩ, 2MΩ, etc. Why the 2s instead of 100, 1K, 10K etc.? Well, here's my guess.
Because the vast majority of resistors are 5%, the resistor values are 5% apart (or so). For example, the "standard" 5% values between 1K and 10K are:
_____________________________________________________________________________________Compare these two videos as I measure a 1KΩ resistor with an autoranging meter:
Which gets the first significant digit instantly, the second digit after 1 second and the final digit after 2.
Expensive autoranging meters, like Fluke 73s, will be super fast so it's not a big deal, but if you have a $200 meter you're probably not reading this tutorial.
Ranges will almost always be something like 200Ω, 2KΩ, 20KΩ, 200KΩ, 2MΩ, etc. Why the 2s instead of 100, 1K, 10K etc.? Well, here's my guess.
Because the vast majority of resistors are 5%, the resistor values are 5% apart (or so). For example, the "standard" 5% values between 1K and 10K are:
1.0K, 1.1K, 1.2K, 1.3K, 1.5K, 1.6K, 1.8K, 2.0K, 2.2K, 2.4K, 2.7K, 3.0K, 3.3K, 3.6K, 3.9K, 4.3K, 4.7K, 5.1K, 5.6K, 6.2K, 6.8K, 7.5K, 8.2K, 9.1K
There are way more values between 1KΩ and 2KΩ than between 2KΩ and 3KΩ, etc. By picking 2KΩ as your max range, you get the best precision for the most probable values.
using multimeter
ENTERTAINMENT SEGMENT
one of my favorites :)
