There is a DIP type resistor that we usually use (it is often said that it is a carbon film resistance)
There is a way to know how many ohms (Ω: resistance unit) this is.
It's called resistance color banding, which is really important.
When I memorized this at first, I muttered and memorized it, but later on, I forgot it..;;
Well, why don't we take it with a tester? But... when do we take it all~
Also, even if the circuit is already soldered, the wrong value is obtained due to the resistance components
There are times when it comes out. Therefore, it is better to put this in your head~ This is it!
As above, for example, if it is brown/black/red/gold... because the first digit is 1 and the second digit is 0... it will be 10..
And when you multiply it by 100, it becomes 1000 = 1K, which becomes 1K ohm.. The error range is within 5%.
In fact, if you actually measure it, it is about 99X ohms, which is slightly lower than 1K.
"How do you distinguish between the front and the back" is gold/silver/colorless. In other words, the color representing the margin of error never comes out first, so you can assume that there are three colors behind and calculate.
But, looking at some, these days, there are also five-color resistors. For five-color, you can think of the third color as the third number in the middle.
In other words, if it is brown/black/black/red/gold, you can see it as 100 * 100 * 5% = 10K, right?
However, these days, rather than DIP-type resistors, chip-shaped resistors are often used.
The size is also very small (it is a size that is hard to solder, so I use a lot of resistance that is about a grain of rice or smaller.
Because you have to use these chip resistors, you can make more compact electronic devices.
These chip resistors have a size number called according to their size, as shown below.
In other words, the size of the chip resistance is distinguished by the above type.
This size distinction is important depending on how to design the size of the metal part when laying out the PCB, so when using the chip resistor in the circuit diagram, you must mark it unconditionally.
However, the size chart above is not only used for chip resistance, but also applies to capacitors, inductors, and other SMD type devices.
If you ask, "But does this chip resistor have a distinctive color band?"
Usually there are 3 numbers written on it (In fact, it is written small so that people with bad eyes cannot see it~ A magnifying glass is required!)
For example, 100 is 10 ohm, 101 is 100 ohm, 102 is 1000=1K ohm, 103 is 10K ohm..
4.7K ohms on 472.
The first two numbers are just numbers like distinguishing the resistance color band. The third number at the end is the number to be multiplied. Easy?^^
But there is a really, really important part of the table above...
It's called Power(W)... This is the rated wattage.
Why is it important,
The resistor is supposed to consume current, so the power consumed here is
I think you know that power (P) = voltage (V) * current (I) (W watt).
If you don't choose a resistor for this power, suddenly the resistor emits black smoke and gives off a very strong smell.
Therefore, a certain amount of voltage is determined, so you have to choose a part by considering the current it takes.
Simply put, even if you have to use 1K ohms, you have to choose the components for the current across this resistor.
In addition to the wattage of the above chip resistance, there are resistances of power such as 1/4W, 1/2W, 1W, 2W as the general DIP type resistance increases.
The resistance of the carbon film DIP type that we see too common is usually 1/4W. The thicker one is 1/2W, the thicker one is 1W. The surface color and feel of the surface of 1W are usually rough. One thing just stands out.
Higher wattage of 5W or 10W has a resistance called cement resistance as shown in the picture above.
It looks really ignorant, but it is an element that can be seen in electronic devices that consume high power.
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