What is the maximum distance between RX and TX coils?

[LauraCx]

What is the maximum distance between RX and TX coils?

This depends on the coil design. Common designs are using 3mm to 5mm of gap. However, we have designed coils for 100W application with 2cm coil distance and with very good efficiency. In general, larger distance results in poor coupling and lower efficiency. Special attention to the coil design and frequency of operation can improve the efficiency.

[theoliverhenry]

That's interesting! It seems like optimizing coil design and frequency is crucial for efficiency in higher power applications like yours. Have you found that tweaking the coil distance significantly impacts performance, or is frequency more of a critical factor in your designs?

[carlbidwell]

Good question! The distance between TX and RX coils really depends on your design. For most Qi-style setups, it’s around 5 mm for good efficiency. Larger or resonant coils can work up to a few centimeters, but the farther apart they are, the more power you lose. In short, keep them as close and well-aligned as possible for the best performance.