A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses.
Understanding the Resistor Codes:
The resistance of a resistor is given in ohms (Ω) and is defined by the color bands that appear along it. The bands are read from left to right. The resistor has 4 bands, and you can see that there are 3 bands and then a bigger gap and the 4th band. The following figure shows the right way of reading the resistor color
Each band means something:
The following table explains those values:
Determining the value of resistance:
The above resistor's color codes are
The tolerance is 5%, which means that the value of resistance can be between 220Ω
±5%. So it can have any value between 209Ω and 231Ω
Sample Resistor Values:
It’s useful to know how to determine the value of a resistor. However, if you search on Google “resistor calculator”, you’ll find several websites
where you select the colors of your resistor, and it automatically calculates the value of resistance.
Resistors in Series and in Parallel:
You can combine resistors to have a specific value of resistance. For instance, you can combine resistors in series or in parallel. The figures below show how to calculate the resistance for both situations
Two 100-ohm resistors in series block twice as much current as a single resistor. Their total resistance is 200 ohms
Resistors in Parallel:
Two 100-ohm resistors in parallel block half as much current as one resistor. Their total resistance is 50 ohms.
Example:
Imagine that R1 = 220Ω and R2 = 270Ω. What’s the total value of resistance in the first and in the second situation?
SMD Resistor:
SMD or mini component resistor in the laptop motherboard serves as a resistance and if its value is 0 - 000, the resistor serves as a jumper (fuse). The color and shape of this resistor on laptop motherboards are generally black, white and green.
In particular, the resistor functions as a resistance, however its use in circuit electronics. In general this component has a complex function depending on the placement on a circuit. Resistor in circuit laptop motherboards generally serve as a resistance, voltage divider, comparator, Pull up, safety, jumper and current limiter.
Characteristics of this component will break the current and voltage or change the value of the voltage itself if damaged, especially in the input circuit, and other problems if the resistors breaks then the input will not flow to the system / IC. The damage caused by this lice resistor is almost all of the characteristics of laptop damage (no charging, totally died, no display, etc.)
Many SMD resistors do not have any markings on them to indicate their value. For these devices, once they are loose and out of their packaging it is very difficult to tell their value. Accordingly SMD resistors are typically used within reels or other packages where there is no chance of different values being mixed.
Many resistors do have markings on them. There are three systems that are used:
EIA96 SMD resistor code system:
A further surface mount resistor code scheme or SMD resistor coding scheme has started to be used, and it is aimed at 1% tolerance SMD resistors, i.e. those using the EIA96 or E-96 resistor series. As higher tolerance resistors are used, further figures are needed. However the small size of SMT resistors makes the figures difficult to read. Accordingly the new system seeks to address this. Using only three figures, the
actual characters can be made larger than those of the four figure system that would otherwise be needed.
The EIA SMD resistor coding scheme uses a three character code: the first 2 numbers indicate the 3 significant digits of the resistor value. The third character is a letter which indicates the multiplier. In this way this SMD resistor marking scheme will not
be confused with the 3 figure markings scheme as the letters will differentiate it, although the letter R can be used in both systems. Precision SMD resistors with 1% of tolerance and with code EIA-96
To generate the system the E-96 resistor series has been taken and each value or significant figure set has been numbered sequentially. As there are only 96 values in the E-96 series, only two figures are needed to number each value, and as a result this is a smart way of reducing the number of characters required.
The details for the EIA SMD resistor code scheme are tabulated below:
For example a resistor that is marked 68X can be split into two elements. 68 refer to the significant figures 499, and X refers to a multiplier of 0.1. Therefore the value indicated is 499 x 0.1 = 49.9Ω.
In this coding scheme, the first three numbers will indicate the significant digits, and the fourth is the multiplier.
The resistor acts as a resistance or current limiter.
Resistor in the laptop motherboard as much as 70% is used as a resistance on the positive input VIN path, the characteristic of this component if it broken will break the voltage.
If the resistance value changes or does not match the recommendation on the circuit schematic, then the resulting output value is not appropriate and have an impact on the error circuit or circuit problem (resistor stretched)
In principle, the voltage divider resistor consists of two resistors arranged in parallel and will produce an output voltage ½ of the input voltage, provided that two resistors have the same resistance value but if the values is different, it will affect the current consumption depending on the value of a resistance.
This system is also often used in comparator circuits, variable resistor circuit on charging and RTC circuit.
Understanding the Resistor Codes:
The resistance of a resistor is given in ohms (Ω) and is defined by the color bands that appear along it. The bands are read from left to right. The resistor has 4 bands, and you can see that there are 3 bands and then a bigger gap and the 4th band. The following figure shows the right way of reading the resistor color
Each band means something:
- The first two bands represent the numbers of the first two digits
- The third band represents the number of zeros after those digits, the multiplier
- The fourth band is the tolerance of the resistance
The following table explains those values:
Determining the value of resistance:
The above resistor's color codes are
- 1st band is red – the first digit is 2
- 2nd band is red – the second digit is 2
- 3rd band is brown – the multiplier is 10^1 = 10
- 4th band is gold – the tolerance is 5%
The tolerance is 5%, which means that the value of resistance can be between 220Ω
±5%. So it can have any value between 209Ω and 231Ω
Sample Resistor Values:
It’s useful to know how to determine the value of a resistor. However, if you search on Google “resistor calculator”, you’ll find several websites
where you select the colors of your resistor, and it automatically calculates the value of resistance.
Resistors in Series and in Parallel:
You can combine resistors to have a specific value of resistance. For instance, you can combine resistors in series or in parallel. The figures below show how to calculate the resistance for both situations
Two 100-ohm resistors in series block twice as much current as a single resistor. Their total resistance is 200 ohms
Resistors in Parallel:
Two 100-ohm resistors in parallel block half as much current as one resistor. Their total resistance is 50 ohms.
Example:
Imagine that R1 = 220Ω and R2 = 270Ω. What’s the total value of resistance in the first and in the second situation?
- Resistors in series : Req = 220 + 270 = 490 Ω
- Resistors in parallel : Req =220×270/220+270 = 121 Ω
SMD Resistor:
SMD or mini component resistor in the laptop motherboard serves as a resistance and if its value is 0 - 000, the resistor serves as a jumper (fuse). The color and shape of this resistor on laptop motherboards are generally black, white and green.
In particular, the resistor functions as a resistance, however its use in circuit electronics. In general this component has a complex function depending on the placement on a circuit. Resistor in circuit laptop motherboards generally serve as a resistance, voltage divider, comparator, Pull up, safety, jumper and current limiter.
Characteristics of this component will break the current and voltage or change the value of the voltage itself if damaged, especially in the input circuit, and other problems if the resistors breaks then the input will not flow to the system / IC. The damage caused by this lice resistor is almost all of the characteristics of laptop damage (no charging, totally died, no display, etc.)
Many SMD resistors do not have any markings on them to indicate their value. For these devices, once they are loose and out of their packaging it is very difficult to tell their value. Accordingly SMD resistors are typically used within reels or other packages where there is no chance of different values being mixed.
Many resistors do have markings on them. There are three systems that are used:
- Three figure SMD resistor coding system
- Four figure SMD resistor coding system
- EIA96 SMD resistor coding system
EIA96 SMD resistor code system:
A further surface mount resistor code scheme or SMD resistor coding scheme has started to be used, and it is aimed at 1% tolerance SMD resistors, i.e. those using the EIA96 or E-96 resistor series. As higher tolerance resistors are used, further figures are needed. However the small size of SMT resistors makes the figures difficult to read. Accordingly the new system seeks to address this. Using only three figures, the
actual characters can be made larger than those of the four figure system that would otherwise be needed.
The EIA SMD resistor coding scheme uses a three character code: the first 2 numbers indicate the 3 significant digits of the resistor value. The third character is a letter which indicates the multiplier. In this way this SMD resistor marking scheme will not
be confused with the 3 figure markings scheme as the letters will differentiate it, although the letter R can be used in both systems. Precision SMD resistors with 1% of tolerance and with code EIA-96
To generate the system the E-96 resistor series has been taken and each value or significant figure set has been numbered sequentially. As there are only 96 values in the E-96 series, only two figures are needed to number each value, and as a result this is a smart way of reducing the number of characters required.
The details for the EIA SMD resistor code scheme are tabulated below:
For example a resistor that is marked 68X can be split into two elements. 68 refer to the significant figures 499, and X refers to a multiplier of 0.1. Therefore the value indicated is 499 x 0.1 = 49.9Ω.
SMD resistors with 3-digit code (values less than 10 n):
As the name indicates this SMD resistor marking system uses three figures. The first two figures in the code indicate the significant figures, and the third is a multiplier. This is the same as the colored rings used for wired resistors, except that actual numbers are used instead of colorsSMD resistor with 4-digit code system Values less than 100 Ω:
The four digits or four figure SMT resistor marking scheme is used for marking high tolerance SMD resistors, its format is very similar to the three figures SMT resistor making scheme, but expanded to give the higher number of significant figures needed for higher tolerance resistors.In this coding scheme, the first three numbers will indicate the significant digits, and the fourth is the multiplier.
SMD Network:
One component can contain multiple resistors that have the same resistance value in one package or component form. This type of resistor we often encounter in the keyboard path, this component is rarely damaged except on the 2000s motherboard output with error keyboard problems.Resistors in the Circuit:
Resistor as ResistanceThe resistor acts as a resistance or current limiter.
Resistor in the laptop motherboard as much as 70% is used as a resistance on the positive input VIN path, the characteristic of this component if it broken will break the voltage.
If the resistance value changes or does not match the recommendation on the circuit schematic, then the resulting output value is not appropriate and have an impact on the error circuit or circuit problem (resistor stretched)
Resistor as a Voltage Divider:
In principle, the voltage divider resistor consists of two resistors arranged in parallel and will produce an output voltage ½ of the input voltage, provided that two resistors have the same resistance value but if the values is different, it will affect the current consumption depending on the value of a resistance.
This system is also often used in comparator circuits, variable resistor circuit on charging and RTC circuit.
Resistor Grounding or Pulldown Resistor:
This resistor is almost never damaged, used in circuit grounding and full down resistor or parallel resistor that one of its legs is connected to ground/ system grounding.Resistor Measurement:
You can check the resistor resistance by selecting the ohm range in the digital multimeter, the display should show OLΩ because, in Resistance mode, even before test leads are connected to a component, a digital multimeter automatically begins taking a resistance measurement, when the leads are connected to a component, a digital multimeter automatically uses the Auto range mode to adjust to the best range, best results will be achieved if the component to be tested is removed from the circuit. If the component is left in the circuit, the readings could be affected by other components in parallel with the component to be tested.Test SMD Resistors:
Attachments
-
1650859492605.png
