Pocket spells for everyday electronics.
A small web app for electronics students and makers. Everything runs in the browser, on desktop or phone.
Resistor color code. Click the bands of the resistor and pick their colors to read its value and tolerance range. Works with 4-band and 5-band resistors. It also works in reverse: type a value like 4.7k and it paints the bands for you.
Ohm's law. Fill in any two of voltage, current, resistance and power, and the other two are calculated.
Voltage divider. Enter the input voltage, R1 and R2 to get the output voltage, the current and the power dissipated in each resistor.
Series and parallel. Paste a list of resistors and get the total resistance both ways.
All fields accept engineering prefixes: 4.7k, 4k7, 20m, 1M, 100u.
No build step and no dependencies. Download the repo and open index.html in any browser.
- 6-band resistors (temperature coefficient)
- Standard E12/E24 value suggestions
- LED series resistor calculator
- RC time constant and cutoff frequency