Resistor Data

A simple module to calculate properties for resistors.

• Convert resistor bands to standard resistor notation
• Convert standard resistor notation to resistor bands
• Convert a number to standard resistor notation
• Convert standard resistor notation to a number

Install

npm install resistor-data

Usage

JavaScript

const { bandsToNotation, notationToBands, notationToValue, valueToNotation } = require('resistor-data');

bandsToNotation(['red', 'yellow', 'black', 'brown', 'brown']); // ['2k4', 1]
notationToBands(['2k4', 1], 5);                                // ['red', 'yellow', 'black', 'brown', 'brown']

notationToValue('2k4');  // 2400
valueToNotation(2400);   // '2k4'

TypeScript

import {
    bandsToNotation,
    notationToBands,
    notationToValue,
    valueToNotation,
} from 'resistor-data';
import type { ResistorColor, ResistorTolerance, ResistorData, BandCount } from 'resistor-data';

// ResistorData is [notation: string, tolerance: ResistorTolerance]
const result: ResistorData = bandsToNotation(['red', 'yellow', 'black', 'brown', 'brown']);
// result => ['2k4', 1]

const bands: ResistorColor[] = notationToBands(['2k4', 1], 5);
// bands => ['red', 'yellow', 'black', 'brown', 'brown']

const value: number = notationToValue('2k4');  // 2400
const notation: string = valueToNotation(2400); // '2k4'

API

bandsToNotation(bands: string[]): ResistorData

Converts an array of 4 or 5 resistor band colour names into [notation, tolerance].

bandsToNotation(['orange', 'orange', 'black', 'red', 'brown']); // ['33k', 1]

notationToBands(data: [string, ResistorTolerance?], bands?: BandCount): ResistorColor[]

Converts a [notation, tolerance] pair into an array of colour names. bands defaults to 5.

notationToBands(['33k', 1], 4); // ['orange', 'orange', 'orange', 'brown']
notationToBands(['33k', 1], 5); // ['orange', 'orange', 'black', 'red', 'brown']

notationToValue(notation: string): number

Converts standard resistor notation to a numeric value.

notationToValue('5k');   // 5000
notationToValue('5k5');  // 5500
notationToValue('1M2');  // 1200000

valueToNotation(value: number | string): string

Converts a numeric value to standard resistor notation.

valueToNotation(3000);    // '3k'
valueToNotation(3300);    // '3k3'
valueToNotation(1000000); // '1m'

Types

Type	Description
ResistorColor	Union of valid band colour strings ('black', 'brown', 'red', ...)
ResistorTolerance	Union of valid tolerance values (0.05, 0.1, 0.25, 0.5, 1, 2, 5, 10, 20)
ResistorData	Tuple returned by bandsToNotation: [notation: string, tolerance: ResistorTolerance]
BandCount	4 | 5