What is it?

This module allows you to extract 5V and up to 1A from a Qi-compliant wireless charger. This is enough to power microcontrollers and sensors, and/or charge a battery, giving it many uses in low power electronics projects. If you need to charge or power your device without a cable, this could be the perfect module for you!

Why did you make it?

I was working on a wearable device which needed to be waterproofed, and therefore using a USB charging port was off the cards. Using this module allowed me to recharge the device's onboard battery wirelessly, so I could encase the electronics in waterproofing epoxy.

Additional info

• The receiver coil must be soldered between the AC1 and AC2 terminals (the polarity does not matter). You need to scrape off the enamel coating on the ends of the receiver coil wire before you solder them.
• If you wish to use your own receiver coil, you may have to modify some capacitors on the PCB to get it working. I recommend consulting the BQ3103B datasheet for this, or you can send me a message.
• The size of the receiver coil is proportional to the maximum load current.
• For wireless power transfer to occur, the transmitter and receiver coils must be sufficiently aligned. This is harder for smaller receiver coils. You must also minimise the gap between the two coils, any larger than 2mm and you will have problems!
• There is an onboard NTC thermistor to switch the regulator off if the device gets too hot or too cold. The working temperature range is 0 - 50°C.