Power Supply Hub With Battery Charger, Quad-USB & Variable Outputs

This power supply hub operates as a comprehensive benchtop energy distribution and conditioning system, relying on an analog architecture without a dedicated microcontroller or digital board. At its core, the circuit utilizes six LM317T linear voltage regulators housed in TO-220 packages to manage and step down input voltages into stable, regulated outputs. Individual heat-sinks, featuring a thermal resistance below 10°C/W, are attached to the regulators to safely dissipate thermal energy generated during voltage conversion. The system incorporates a combination of fixed-value resistors (such as R2, R3, R6, R14, and R18) and a potentiometer (VR1) to configure the output voltages and current limits, allowing the LM317T regulators to function effectively for both voltage regulation and constant-current battery charging. Filter capacitors and protective diodes are integrated across the circuit to suppress voltage spikes, smooth out ripple currents, and prevent reverse-current damage. User control is managed through an array of switches (S1 through S10) that route power selectively to different sections of the board. Visual status indicators are provided by multiple LEDs that light up to confirm active power rails. The conditioned power is then distributed via four USB connectors (CON3 through CON6) to deliver steady 5.1V lines, while separate output terminals (CON7, CON8, and CON9) supply the variable voltage range spanning from 1.2V to 6.5V and the battery charging pathways.