PCB trace width calculator
Online trace width calculator to IPC-2221: outer and inner layers, cross-sectional area, trace resistance and voltage drop.
Heatsink calculator
Online heatsink thermal calculator: the thermal resistance needed, the junction temperature, the effect of thermal compound and airflow, and an area estimate.
Divider, LED and zener calculator
Online calculator for three basic circuits: the series resistor for an LED, a voltage divider with its load taken into account, and a zener shunt regulator.
555 timer calculator
Online NE555 timer calculator: frequency and duty cycle in astable mode, component values for a target frequency, and monostable mode.