E12 series, which only has 12 allowed values per decade. In addition to the values of the e24 series as quoted, intermediate values, higher value of the e24 series. Constant application of a voltage above the rated voltage will degrade the performance and reliabillity of the resistor. They are the standard e3, e6, e12, e24, e48 and e96 resistor values. Although there are online tools available for this task, it is often useful to be able to integrate scriptable functions into custom software. These standard resistor values are those which can be bought. Resistor color code system how to read the resistor code. The e3 series resistors are the most widely used and hence these values will be the most common resistor values used within the electronics industry. If there is only one black band in the center, the resistor is called a zero ohm resistor. In this article youll find an interactive table in which you can find the standard resistor values, as used in electronics, and defined by the iec. Standard series values in a decade for resistances and capacitances e3 to e192 according to iec 60063 e192 e96 e48 e192 e96 e48 e192 e96 e48 e192 e96 e48 e24 e12 e6 e3 100 100 100 178 178 178 316 316 316 562 562 562 10 10 10 10 101 180 320 569 11 102 102 182 182 324 324 576 576 12 12 104 184 328 583. A larger physical size indicates a higher power rating.
Successive values within a decade series are related approximately by a factor of for the e12 series, for the e24 series, for the e96 series and for the e192 series. You want to find the e24e48e96 resistor value that is closest to a given exact value programmatically using python. Preferred number series for resistors and capacitors specifies the preferred values in the e24 series, which is the most often used. The more accuracy closer tolerance needed in resistors chosen for a particular purpose, the more values must be in the range chosen and generally the more expensive each resistor will be. Selecting resistor values traditionally has been a manual process where the calculated value is. Kitronik ltd how to calculate and understand resistor values resistors a resistor is a device that opposes the flow of electrical current. Selecting resistor values traditionally has been a manual process where the calculated value is matched to a real value in a printed lookup table.
Eia standard resistor values by tolerance% move the decimal point to achieve the actual value desired. Resistor values is an electrical engineering program that will calculate the value of a 4 band resistor. Table at right shows both the e12 and e24 allowed values for comparison. They are particularly useful for resistor values that are not in any way critical. Other eia standards define the values for other tolerance ranges. The e series is a system of preferred numbers also called preferred values derived for use in electronic components. Download preferred resistor values lookup for free. Power rating depends on the resistors construction. The eia e number is the number of logarithmic steps. Standard resistor values in 1952 the iec international electrotechnical commission decided to define the resistance and tolerance values into a norm, to ease the mass manufacturing of resistors.
The nominal resistance and tolerance are marked on the resistor using four or five colored bands in accordance with iec 60062, marking codes for resistors and capacitors. As you can see in the chart, e24 values are nicely spaced between 100 and 1k ohms. It makes little sense to produce a 105 ohm resistor since 105 ohms falls within the 10% tolerance range of the 100 ohm resistor. Standard resistance values for the 10 to 100 decade. The others values can be obtained by multiply these values for powers of 10. Do not use the products beyond the specifications described in this catalog.
In addition to the values of the e24 series as quoted, intermediate. Examples 4 7 3 2 a 1st digit of the resistors value b 2nd digit of the resistors value c 3th digit of the resistors value. Using 10% tolerance devices as an example, suppose that the first preferred value is 100 ohms. These older values were used to create the e6, e12, e24 series standard that was accepted in paris in 1950. The rationale is simple select values for components based on the tolerances with which they are able to be manufactured. It consists of the e3, e6, e12, e24, e48, e96 and e192 series, where the number after the e designates the quantity of value steps in each series. If an additional fifth band is white, the resistor is a fusible resistor. Generally, if an additional fifth band is black, the resistor is a wirewound resistor. Make sure at least the e12 series values are included, preferably also the e24 series for larger sets. Finds the closest combination of two resistors from the e24 or e96 set of preferred values for a given resistance value. Note 1 for a list of e24, e96 and e192 standard resistance values, see productfilesresistorsapplicationnotestn005eiastandardvaluesfor resistors. Using standard resistor values can greatly impact the accuracy and predictability of a circuit by eliminating rounding errors incurred at the end of the design.
Standard series values in a decade for resistances and. Thick film precision rohs flat chip resistors rk73h flat. The name e24 comes from the fact that there are 24 values per decade of resistance. The e192 series of standard resistor values also exist, but their use is much smaller than those in the other ranges given above. Below 100 ohms or above 1k, the series simply repeats. This application lists the e24 resistor sizes, perfect for electrical and electronic engineers or electronics hobbyists to select the correct resistance values for their lab projects. Eia standard resistor values stackpole electronics, inc. The trial version of resistor values is limited to resistance values of. You want to find the e24 e48e96 resistor value that is closest to a given exact value programmatically using python. This specification may be changed at any time without prior notice.
Table 2 lists the standard values of primary interest to amateurs. The bigger the value of a resistor the more it opposes the current flow. Following this logic, the preferred values for 10% tolerance resistors between 100 and 1,000 ohms would be 100, 120, 150, 180, 220, 270, 330 and so on rounded appropriately. Resistor values will determine the value of a resistor based on the color bands or the reverse, it can display the color bands of a resistance value entered by the user.
For flat chip jumper resistor, please refer to rk73z series. Resistor color coding applying the color code the amount by which the actual r can differ from the colorcoded value is its tolerance. The 120 ohm resistor has a value ranging between 110 and ohms. Youll find the values for the e6, e12, e24, e48, e96 and e192 series or preferred resistor values in this table. This calculator will select the closest standard resistor value, from 1% 5% or 10% standard eia values, calculates the error, and prints out a table of the standard values for the given tolerance. When resistor is to be exposed to a transient load excessive large load,such as pulse, mount the resistor on your product and check the condition and evaluate the result.
Resistor with a tolerance of 5%, 10% or 20% are much easier to read you do not always need resistors with lower tolerances. Resistors are available with ratings from a fraction of an ohm to millions of ohms, but they come in standard values only. The design and specifications in this catalog are subject to. Packaging type code quantity packaging style width pitch dimensions sfr16s a5 5000 taped acc. Two decades of e12 values, which would give resistor values of 1. Use of standard values is encouraged because stocking progr ams are designed around them. That is, resistors are not available for every possible ohmic roundnumber value. These are referred to as preferred values or eseries, and they are published in standard iec 60063. When decoding the resistor color bands, consult a resistor color code table like the one below. In 1952 the iec international electrotechnical commission decided to define the resistance and tolerance values into a norm, to ease the mass manufacturing of resistors.
Resistors are available in a number of standard ranges, often called preferred values these ranges, or series, are set out by the electronic industries association eia, and are e3, e6, e12, e24, e48, e96 and e192. Finding the nearest e96 resistor value in python techoverflow. Jan 02, 20 using standard resistor values can greatly impact the accuracy and predictability of a circuit by eliminating rounding errors incurred at the end of the design. Resistor color codes color value black 0 brown 1 red 2 orange 3 yellow 4 green 5 blue 6 violet 7 gray 8 white 9 the first two colors on the resistor shown in figure ht43 are actual numbers, read directly from the color table, as shown in table ht41. They are commonly available from component suppliers. Metal film thin film chip resistors, high reliability type metal. For example, for e12 has twelve steps between any power. These values are generally available in multiples of 0. The e24 series is for resistors with a 5% tolerance precision. How to read the resistor code first find the tolerance band, it will typically be gold 5%. The tolerance band on a resistor indicates the spread of possible values of any particular resistor, for example a resistor marked as 47k.
Melf and leaded resistor products e24 series melf and leaded resistor products e96 series and e192 series band 2 coding band 1 coding band 3 coding band 4 coding band 5 coding tc dots near band 4 or 6 tc 1001. The values are as follows and note there are 24 values per column or decade, hence e24. The number after the e denotes the number of values the series contains per decade. Notice that the colors on this resistor are in order red, green, orange, and silver. Those valid values are prescribed in jisc5063, iec60063, etc.
For the first two bands, find that colors corresponding digit value. The e6 range has 6 values, and the e24 range 24 values per decade. If there is no tolerance band, then find the side that has a band closest to a lead and make that the first band. Nikkohm has used numerical values of iec standard with addition of 2. Duplicated resistance values as e24 series part numbers shall follow. Thick film precision rohs flat chip resistors rk73h flat chip.
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