Water Dispenser

Design Motivation & Ideas

This Automated Water Dispenser Controller was designed to provide a compact, reliable, and easily mountable fluid delivery solution. The circular form factor was specifically chosen to allow for seamless mechanical integration into cylindrical enclosures, such as standard water bottles or custom 3D-printed housings. The core design objective was to safely isolate standard 5V control logic from the high-current inductive load of a DC water pump, ensuring that inrush currents and flyback voltage spikes do not interfere with or damage connected microcontrollers or proximity sensors.

Project Overview

This project is a custom-designed, circular Automated Water Dispenser Controller. Built upon a regulated 5V high-current driver architecture, this board is specifically engineered to safely and reliably control a DC water pump. The circular PCB form factor was deliberately chosen to allow for seamless integration into cylindrical enclosures, such as standard water bottle necks or custom 3D-printed dispenser housings.

Technical Specifications & Circuit Architecture

1. Pump Actuation & Control

• High-Current Driver: Utilizes a TIP127 Darlington transistor (Q2) to switch the heavy inductive load of a DC water pump. This allows the pump to be triggered by a low-power external signal connected to the input header (H2), such as an infrared (IR) proximity sensor or a microcontroller.

• Motor Protection: Integrates a 1N4007 flyback diode (D1) directly across the pump output terminals (H1). This suppresses destructive high-voltage spikes generated when the water pump motor shuts off, protecting the control logic.

2. Power Management

• Stable Regulation: Power is supplied via a standard DC barrel jack and stepped down through an onboard LR7805 linear regulator, providing a clean 5V rail for both the pump and any connected sensors.

• Inrush Current Handling: Features a massive 1000uF electrolytic bulk capacitor to absorb the sudden power draw when the pump motor first turns on. This prevents voltage droop that could otherwise reset or glitch sensitive input sensors.

3. Interface & Hardware Design

• Optimized Form Factor: A compact, circular footprint designed specifically for practical mechanical mounting in fluid delivery systems.

• Visual Status Indicators: Dual front-facing LEDs (LED1 and LED2) provide immediate visual feedback for main power status and active dispensing state.

• Custom Silkscreen: Features clear component labeling, custom mascot artwork, and personalized branding on the top layer for a highly professional finish.