A resistor is an electronic component that has a fixed resistance value, the way to measure it is if the capacity R is small, then the number used on the ohm meter is also small, resistors made of charcoal are usually able to support very small electrical power, namely 0.25W to 1W, while for larger powers they are usually made of nickel wire rolled with marble or glass.
Resistor Family
Resistor Symbol
Resistors are divided into two categories:
- Linear Resistor
- Non-linear resistors
1. Linear Resistor
The unit of resistance is ohm or W.
Color Code On Resistors
In low-power resistors, the size is indicated by the color code on the resistor body. The color code on the resistor indicates the resistance value and its tolerance, so it is important to understand that the real value of a resistor will be determined by the value listed according to the color code +, - the value of its tolerance (so a good resistance value is one with a small tolerance, or the value is still within the tolerance limits).
Resistor Color Code
Resistor Color Marking
Many resistors in the future will be coded according to BS 1852 (Colour Code) the resistor's price and tolerance will be stamped on the body instead of the coloured rings that are familiar today.
Behind the price code will be added letters to indicate the tolerance:
F = ± 1% G = ± 2% J = ± 5% K = ± 10% M = ±20%Resistance Code Example According to BS1852
| Penandaan | Resistansi |
|-----------|----------------|
| R33M | 0.33 Ohm ± 20% |
| 4k7F | 4700 Ohm ± 1% |
| 6M8M | 6.8M Ohm ± 20% |
| 22KK | 22K Ohm ± 10% |
| 0.5% | 1% | 2% | 5% | 10% | 20% | 50% |
|------|-----|-----|-----|-----|-----|-----|
| 100 | 100 | 100 | 100 | 100 | 100 | 100 |
| 101 | | | | | | |
| 102 | 102 | | | | | |
| 104 | | | | | | |
| 105 | 105 | 105 | | | | |
| 106 | | | | | | |
| 107 | 107 | | | | | |
| 108 | | | | | | |
| 109 | | | | | | |
| 110 | 110 | 110 | 110 | | | |
| 111 | | | | | | |
| 113 | 113 | | | | | |
| 114 | | | | | | |
| 115 | 115 | 115 | | | | |
| 117 | | | | | | |
| 118 | 118 | | | | | |
| 120 | | | 120 | 120 | | |
| 121 | 121 | 121 | | | | |
| 123 | | | | | | |
| 124 | 124 | | | | | |
| 126 | | | | | | |
| 127 | 127 | 127 | | | | |
| 129 | | | | | | |
| 130 | 130 | | 130 | | | |
| 132 | | | | | | |
| 133 | 133 | 133 | | | | |
| 135 | | | | | | |
| 137 | 137 | | | | | |
| 138 | | | | | | |
| 140 | 140 | 140 | | | | |
| 142 | | | | | | |
| 143 | 143 | | | | | |
| 145 | | | | | | |
| 147 | 147 | 147 | | | | |
| 149 | | | | | | |
| 150 | 150 | | 150 | 150 | 150 | |
| 152 | | | | | | |
| 154 | 154 | 154 | | | | |
| 156 | | | | | | |
| 158 | 158 | | | | | |
| 160 | | | 160 | | | |
| 162 | 162 | 162 | | | | |
| 164 | | | | | | |
| 165 | 165 | | | | | |
| 167 | | | | | | |
| 169 | 169 | 169 | | | | |
| 172 | | | | | | |
| 174 | 174 | | | | | |
| 176 | | | | | | |
| 178 | 178 | 178 | | | | |
| 180 | | | 180 | 180 | | |
| 182 | 182 | | | | | |
| 184 | | | | | | |
| 187 | 187 | 187 | | | | |
| 189 | | | | | | |
| 191 | 191 | | | | | |
| 193 | | | | | | |
| 196 | 196 | 196 | | | | |
| 198 | | | | | | |
| 200 | 200 | | 200 | | | |
| 203 | | | | | | |
| 205 | 205 | 205 | | | | |
| 208 | | | | | | |
| 210 | 210 | | | | | |
| 213 | | | | | | |
| 215 | 215 | 215 | | | | |
| 218 | | | | | | |
| 220 | | | 220 | 220 | 220 | 220 |
| 221 | 221 | | | | | |
| 223 | | | | | | |
| 226 | 226 | 226 | | | | |
| 229 | | | | | | |
| 232 | 232 | | | | | |
| 234 | | | | | | |
| 237 | 237 | 237 | | | | |
| 230 | | | | | | |
| 240 | | | 240 | | | |
| 243 | 243 | | | | | |
| 246 | | | | | | |
| 249 | 249 | 249 | | | | |
| 252 | | | | | | |
| 255 | 255 | | | | | |
| 258 | | | | | | |
| 261 | 261 | 261 | | | | |
| 264 | | | | | | |
| 267 | 267 | | | | | |
| 270 | | | 270 | 270 | | |
| 271 | | | | | | |
| 274 | 274 | 274 | | | | |
| 277 | | | | | | |
| 280 | 280 | | | | | |
| 284 | | | | | | |
| 287 | 287 | 287 | | | | |
| 291 | | | | | | |
| 294 | 294 | | | | | |
| 298 | | | | | | |
| 300 | | | 300 | | | |
| 301 | 301 | 301 | | | | |
| 305 | | | | | | |
| 309 | 309 | | | | | |
| 312 | | | | | | |
| 316 | 316 | 316 | | | | |
| 320 | | | | | | |
| 324 | 324 | | | | | |
| 328 | | | | | | |
| 330 | | | 330 | 330 | 330 | |
| 332 | 332 | 332 | | | | |
| 336 | | | | | | |
| 340 | 340 | | | | | |
| 344 | | | | | | |
| 348 | 348 | 348 | | | | |
| 352 | | | | | | |
| 357 | 357 | | | | | |
| 360 | | | 360 | | | |
| 361 | | | | | | |
| 365 | 365 | 365 | | | | |
| 370 | | | | | | |
| 374 | 374 | | | | | |
| 379 | | | | | | |
| 383 | 383 | 383 | | | | |
| 388 | | | | | | |
| 390 | | | 390 | 390 | | |
| 392 | 392 | | | | | |
| 297 | | | | | | |
| 402 | 402 | 402 | | | | |
| 407 | | | | | | |
| 412 | 412 | | | | | |
| 417 | | | | | | |
| 422 | 422 | 422 | | | | |
| 427 | | | | | | |
| 430 | | | 430 | | | |
| 432 | 432 | | | | | |
| 437 | | | | | | |
| 442 | 442 | 442 | | | | |
| 448 | | | | | | |
| 453 | 453 | | | | | |
| 459 | | | | | | |
| 464 | 464 | 464 | | | | |
| 470 | | | 470 | 470 | 470 | 470 |
| 475 | 475 | | | | | |
| 481 | | | | | | |
| 487 | 487 | 487 | | | | |
| 493 | | | | | | |
| 499 | 499 | | | | | |
| 511 | 511 | 511 | | | | |
| 517 | | | | | | |
| 523 | 523 | | | | | |
| 530 | | | | | | |
| 536 | 536 | 536 | | | | |
| 542 | | | | | | |
| 549 | 549 | | | | | |
| 556 | | | | | | |
| 560 | | | 560 | 560 | | |
| 562 | 562 | 562 | | | | |
| 569 | | | | | | |
| 576 | 576 | | | | | |
| 583 | | | | | | |
| 590 | 590 | 590 | | | | |
| 597 | | | | | | |
| 604 | 604 | | | | | |
| 612 | | | | | | |
| 619 | 619 | 619 | | | | |
| 626 | | | | | | |
| 634 | 634 | | | | | |
| 642 | | | | | | |
| 649 | 649 | 649 | | | | |
| 657 | | | | | | |
| 665 | 665 | | | | | |
| 673 | | | | | | |
| 680 | | 680 | 680 | 680 | | |
| 681 | 681 | 681 | | | | |
| 690 | | | | | | |
| 698 | 698 | | | | | |
| 706 | | | | | | |
| 715 | 715 | 715 | | | | |
| 723 | | | | | | |
| 732 | 732 | | | | | |
| 741 | | | | | | |
| 750 | 750 | 750 | 750 | | | |
| 759 | | | | | | |
| 768 | 768 | | | | | |
| 777 | | | | | | |
| 787 | 787 | 787 | | | | |
| 796 | | | | | | |
| 806 | 806 | | | | | |
| 816 | | | | | | |
| 820 | | | 820 | 820 | | |
| 825 | 825 | 825 | | | | |
| 835 | | | | | | |
| 845 | 845 | | | | | |
| 856 | | | | | | |
| 866 | 866 | 866 | | | | |
| 876 | | | | | | |
| 887 | 887 | | | | | |
| 898 | | | | | | |
| 909 | 909 | 909 | | | | |
| 910 | | | 910 | | | |
| 920 | | | | | | |
| 931 | 931 | | | | | |
| 942 | | | | | | |
| 953 | 953 | 953 | | | | |
| 965 | | | | | | |
| 976 | 976 | | | | | |
| 988 | | | | | | |Fixed Resistor
It is a resistor whose resistance value has been set by the manufacturer, as well as its tolerance limit, so that even if it experiences changes it must not exceed the tolerance limit. If the resistance value exceeds the tolerance limit, then it is enough to sentence the resistor to DAMAGED.
Variable Resistor
Examples of variable resistors are potentiometers and potentiometer trimmers.
What must be noted is that in installing the potentiometer legs, they must not be reversed. If the installation is reversed, then the rotation of the potentiometer to the maximum will produce a minimum ohm value.
How to Determine the Potentiometer Legs
Read more HERE .
Uses of Resistors
- Voltage sharing
- Fighting tension
- Adjusting the sound volume (volume control)
- Adjusting the low tone (bass control)
- Adjusting the treble control
- Balance control
Voltage and Current Divider Resistor
Series Circuit Analogy
Example of Series Network Calculation
Parallel Circuit Analogy
Example of Discussion of Series and Parallel Resistor Circuits
Calculate the value of Rtot, I, and V from each value of R in the circuit below!
Series and Parallel Circuit Problem Solving
2. Non-linear resistors
It is a resistor whose resistance value changes based on the environment such as temperature or light. Here are some examples:
Resistor Photo Symbol
Photo Resistor Characteristics: When exposed to light, the resistance value decreases to hundreds of ohms. Conversely, if not exposed to light or even in a dark place, the R value can swell to millions of ohms.
Thermistor Symbol
Thermistors are divided into 2 types:
- Positive temperature coefficient (ptc)
- Negative temperature coefisient (n.t.c).
Simbol Voltage-Dependent Resistor (VDR)
VDR Characteristics: When the voltage increases, the R value decreases. But when the voltage decreases, the R value increases.
Testing Resistors (R)
- Place the selector switch in the ohm meter (range) position.
- Attach each plug to the resistor leg. When measuring, do not let both hands touch the resistor legs (you can touch only one).
- Pay attention to the needle on the scale board. If it moves, the resistor is good, if it is still, the resistor is broken.
Using Voltage Resistance Technique
- Rarely used in industrial instrumentation and control repair. Although the part of the equipment is known, it is not allowed to measure voltage and resistance without having a very detailed data book from the factory, because industrial control systems always treat varying power levels. This means that voltage measurements can only be displayed with different instruments.
- Before starting a measurement, carefully observe the manufacturer's data for the conditions under which the measurement should be started.
- Another important consideration is the impedance of the equipment. If it is specified in the manufacturer's data, make sure that the meter follows the manufacturer's data so as not to overload the equipment.
- Most transducers have low impedance, but when the output impedance is high using the wrong meter can reduce the circuit load. Be careful with bridged transducers, if you connect a low impedance meter to the bridge, the system will become unstable and produce false readings (figure 7.9).
Gambar 7.9 Strain Gauge Bridge
- This bridge test is simply by measuring the DC resistance on each leg, usually worth 100 Ohms. When the load is maximum, there will be a small drop (2-3 Ohms) on the bridge and this will be difficult to detect by an Ohmmeter, so by using differential amplifier gain in no-load and full-load conditions, the difference in output signals will indicate whether the bridge is working properly or not.
- Indeed, in the Resistance-Voltage technique, there is not much use of measuring equipment, just a multimeter is enough. But here you must choose a multimeter that suits your needs.
- Another use in industrial control is voltage and power amplifiers. In essence, this is actually the same type of AC amplifier found in audio amplifiers and Hi-Fi equipment. Therefore, when an industrial control circuit containing a voltage or power amplifier is found, when trying to find the damage, take the steps as discussed in Chapter 6 of this book.
SIGNAL-TRACING restrictions
- The Signal-Tracing method is less suitable and not recommended for use in closed-loop servo systems because it will be complicated / slow / rigid to check and you must know the circuit diagram well.
- Precision measuring equipment must be available because it must be able to measure various voltage levels from very small (transducer output) to large (amplifier output) and not burden the circuit.
- The system manual and data book of the components used to view the input/output data of a component must be available.
- More suitable for open loop system, digital system, TV, HIFI etc. which signal change is simple.
Input and Output Signal Check
The measurement method is as follows:
- It is better to measure the AC input signal (output from the transducer) using an oscilloscope (high impedance) to see the frequency, amplitude and distortion and not to overload the existing circuit.
- Measuring the DC input signal from the transducer output requires a high impedance probe and a very sensitive meter (millivolts/microvolts).
- Measuring the output signal of the solenoid and motor is usually around 5 to several hundred volts, which can be measured by a standard voltmeter. To find out whether the voltage is AC or DC according to the motor based on the table in Figure 3. To produce linear motion on the solenoid, it requires an AC or DC pulse.
- Phneumatics and hydraulics are basically air or liquid and gas taps controlled by solenoids that open/close (nothing electronic to fix in this section).
Input and Output Signal Check Steps
NOTE! If the proper voltage is applied to the solenoid and the faucet does not operate, then the entire actuator must be replaced.