Resistance in parallel calculation: R = 1 / (1/R1 + 1/R2 + ... + 1/Rn) Product overview A compact resistor module for USB load testing and discharge. It uses fixed resistors and switchable parallel connections to provide selectable, known loads in a simple, passive package. Configurations and performance - When all switches are open: 2.2 ohm 10 W and 4.7 ohm 10 W - When both resistors are connected in parallel: the load is lower, enabling higher current at a given voltage (up to about 3 A at 5 V) - Actual current is determined by I = V / R and should be calculated for your setup Benefits - Simple, reliable load options with no active electronics - Fast setup for bench testing, discharge simulations, and demonstrations - Fixed power ratings with margin for safe operation - Compact, passive design suitable for lab benches and USB test rigs Technical notes - Three load configurations controlled by switches - Two fixed resistors: 2.2 Ω 10 W and 4.7 Ω 10 W - Currents computed from Ohm's law for the given voltage and selected resistance Use cases - Test USB chargers and power supplies under heavy load - Simulate battery or USB device discharge for evaluation - Demonstrate regulator response and thermal behavior in classrooms or labs