🔌 Électronique
Décodeurs de résistances, calculateurs LED, outils pour condensateurs et plus
Décodez les codes couleur 4 et 5 bandes instantanément. Calculateur visuel gratuit.
Ouvrir l'outil →Calculez la résistance pour un circuit LED. Tension et courant.
Ouvrir l'outil →Décodez les codes de condensateurs céramiques à 3 chiffres (ex. 104 = 100nF).
Ouvrir l'outil →Calculez la tension de sortie d'un diviseur de tension. Entrez Vin, R1, R2.
Ouvrir l'outil →Calculez fréquence, rapport cyclique et temporisation pour circuits 555.
Ouvrir l'outil →Calculez la largeur de piste PCB minimale selon IPC-2221.
Ouvrir l'outil →Tableau de référence AWG avec diamètre, section, résistance et courant max.
Ouvrir l'outil →Calculez la constante de temps, le temps de charge et les courbes RC.
Ouvrir l'outil →Décodez les codes couleur d'inductance 4 bandes en µH et mH.
Ouvrir l'outil →Ajoutez des appareils, consultez la puissance totale, les kWh quotidiens et le coût annuel d'électricité
Ouvrir l'outil →Décodez les codes SMD 3 chiffres, 4 chiffres et EIA-96.
Ouvrir l'outil →Component maths for people with a breadboard in front of them. These tools cover the calculations you hit repeatedly while building a circuit: what resistor a part needs, what a colour band or SMD marking means, how wide a trace has to be, and how long an RC network takes to settle.
Everything is worked in the open. Each tool shows the formula it used and the numbers it put into it, so you can check the result against your own working rather than trusting a black box — which matters when the consequence of a wrong answer is a dead component.
Which tool do I want?
| If you… | Use |
|---|---|
| You have a resistor in hand and need its value | Décodeur de couleurs de résistance |
| The part is surface-mount with a 3 or 4 character code | Décodeur de codes résistance SMD |
| You are driving an LED and need the series resistor | Calculateur de résistance LED |
| You need to drop a voltage down to a reference level | Calculateur diviseur de tension |
| You are sizing wire for a current, or worried about heat | Référence de jauge de fil (AWG) |
| You are laying out a board and need copper width | Calculateur largeur de piste PCB |
| You are building a timer or oscillator | Calculateur de minuterie 555 |
| You need a time constant for filtering or debouncing | Calculateur de constante de temps RC |
Tolerance is the thing beginners forget
Every calculation here produces an exact number, and no component you can buy is exact. A resistor sold as 220 Ω with a gold band is guaranteed only to sit within 5% of that — anywhere from 209 to 231 Ω. Stack a few 5% parts in one divider and the output can drift further than the reading you were trying to achieve.
This matters most where a result feeds a threshold. A divider setting a comparator trip point, a timing network deciding a pulse width, a current limit sitting just under a part's maximum — in those places, work out what the answer becomes at the tolerance extremes, not just at the nominal value. Where it matters, buy 1% parts; they cost almost nothing more.
The same applies to the standard value the tools round to. E24 gives you 24 values per decade, so the nearest stocked resistor to a calculated 237 Ω is 240 Ω. That is usually fine, and the tools tell you both numbers so you can decide.