Wireless DC Power Transfer System for Emergency Charging

Overview

A wireless DC power transfer system designed for emergency scenarios where AC power is unavailable — enables a battery to wirelessly charge DC-powered devices like mobile phones without any AC adapter.

Current Status

• Hardware prototype built and tested
• LTspice simulation completed
• Current efficiency: ~25%
• Target efficiency: 50–60% (work in progress)

How It Works

1. Wien Bridge oscillator generates ~6.6 kHz sine wave
2. Class AB push-pull stage drives the transmitter coil
3. LC resonant filter (tuned to ~6.8 kHz) enables wireless energy transfer
4. Full-wave bridge rectifier converts received AC back to clean DC output

Planned Improvements

• Add permanent magnets to enhance flux linkage between coils
• Optimise coil geometry to reduce flux leakage
• Target: improve efficiency from ~25% to 50–60%

Simulation Details

• Tool: LTspice
• Oscillation frequency: ~6.6 kHz
• Supply: ±15V
• Components: Op-Amp, 2N3904/2N3906, 1N5817 Schottky diodes

Designer

Dhruv — B.Tech ECE, NIT Jalandhar