PCB trace width calculator
PCB trace width calculator to IPC-2221 — width for your current on outer and inner layers, cross-section, trace resistance and voltage drop.
Heatsink calculator
Heatsink calculator — the thermal resistance you need, junction temperature, the effect of thermal paste and airflow, and an estimate of the area.
Divider, LED and zener calculator
Three basic circuits — LED series resistor, a voltage divider with its load taken into account, and a zener shunt regulator. Values for your voltages and currents.
555 timer calculator
555 timer calculator — astable frequency and duty cycle, component values for a target frequency, and monostable mode, with the circuit and formulas.