Guide
Ideal vs loaded voltage divider behaviour
Understand the difference between an ideal voltage divider and a loaded voltage divider, including when load resistance changes the output.
Electronics engineering guides
Use these explainers when a calculator result needs circuit context, a worked example, common failure modes, or a practical next check.
Circuit and resistor guides
Follow a guide for design context, then use the linked calculator for the numerical check.
Guide
Voltage divider tolerance and worst-case output error
Estimate how resistor tolerance and loading affect voltage-divider output error before using the divider as a reference or ADC input.
Guide
LED resistor sizing and resistor power derating
Size an LED series resistor and check resistor dissipation, current margin, and practical wattage selection.
Guide
Resistor power, wattage, and derating margin
Understand resistor power dissipation, wattage selection, and why calculated power is not the same as a safe package choice.
Guide
Pull-up resistor value trade-offs for logic inputs
Choose pull-up resistor values by balancing sink current, logic-low margin, leakage, rise time, and static power.
Analogue and filter guides
Follow a guide for design context, then use the linked calculator for the numerical check.
Guide
RC cutoff frequency and RC time constant
Understand how RC cutoff frequency and RC time constant describe the same resistor-capacitor pair in frequency and time domains.
Guide
AC coupling capacitor sizing and high-pass corner frequency
Choose an AC coupling capacitor by identifying the effective resistance, cutoff frequency, settling time, and bias constraints.
Guide
Op-amp gain resistor selection and tolerance effects
Choose op-amp feedback resistors while considering ideal gain, resistor ratio tolerance, bandwidth, noise, input bias current, and output swing.
Power and energy guides
Follow a guide for design context, then use the linked calculator for the numerical check.
Guide
Capacitor energy and hold-up time
Estimate capacitor stored energy and understand why hold-up time depends on voltage range, effective capacitance, load current, and discharge path.
Guide
Inductor energy, peak current, and clamp paths
Understand stored inductor energy, peak current, saturation margin, and why interrupted current needs a defined clamp or energy path.
Guide
Regulator power dissipation and thermal rise
Understand first-pass regulator dissipation and thermal rise before relying on package ratings or ambient assumptions.
PCB and engineering utility guides
Follow a guide for design context, then use the linked calculator for the numerical check.
Guide
PCB trace current, voltage drop, and temperature rise
Understand how PCB trace current checks connect resistance, voltage drop, copper geometry, and temperature rise.
Guide
Via current, temperature rise, and manufacturability
Understand via current checks across resistance, plating, thermal rise, manufacturability, and parallel via sharing.