Support Request: Issue with STWBC86-Based Project and STEVAL-WBC86TX Evaluation Board

[DZaot1]

Hello everyone,

I'm reaching out to the community because I'm encountering an issue with a Wireless Charger board we designed, based on STWBC86 and a similar architecture to the STEVAL-WBC86TX evaluation board.

The main problem is the Power Transmitter locking up when the receiver is moved away. I've noticed that our board loses control when the receiver device is moved away and when a current exceeding a certain threshold is absorbed. Additionally, we've observed that our board takes much longer compared to the STEVAL-WBC86TX to return to the "PING" state as soon as the receiver is moved away.

We're seeking advice or suggestions on how to address this issue. We've carefully examined the configuration and operation of our board, but so far, we haven't been able to resolve the problem.

If anyone has had similar experiences or is familiar with the operation of Wireless Charger devices based on STWBC86, we would be extremely grateful for any help or insight you can offer.

Thank you in advance for your support, and I wish you all a good day!

Best regards,

Domenico Zaottini

[willzhou · Accepted solution]

Hi 

About "we've observed that our board takes much longer compared to the STEVAL-WBC86TX to return to the "PING" state as soon as the receiver is moved away."

It is because default ping interval is 2000ms, if you want to make it short, you need to modify this value.

[DZaot1]

Hello willzhou,

First of all, I want to thank you for your response. I have tried various attempts both with the STEVAL-WBC86TX and with my PCB, setting the "TX PING INTERVAL" parameter differently as you suggested, and I also tried clicking "TX PING HALF BRDG", but the issue has not been resolved.

Let me provide more detailed explanation of the issues encountered:

1. Upon removing the receiver, sometimes my PCB (WBC86TX component) continues to transmit for a few seconds and then gets stuck in an UNKNOWN condition where it draws only a few tens of mA, disconnecting from communication with WPSTUDIO.
2. The above-described stuck condition also occurs in standalone operation without WPSTUDIO connection.
3. It is possible to reach the same stuck situation by moving the receiver to increase the transmitted power to it.

In addition, I have conducted further tests with default parameters on both boards (both the STEVAL Evaluation Board and my WBC86TX PCB), and I have recorded the following charts directly from WPSTUDIO's "Charts" feature, hoping they may be useful to your community in assisting me with resolving the issue:

FIG 1

FIG 1 depicts the operation of the STEVAL-WBC86TX: after a certain runtime (approximately 419 s), as indicated by the "Voltage" graph, the system transitions from 8V to 7V when the receiver is removed and returns to the PING phase.

Now, considering the following graph referring to my PCB (WBC86TX):

FIG 2

FIG 2: Initially, the board was functioning correctly as it transitioned from the transmission phase to the Ping phase. However, after a certain period (approximately 410s), the Voltage dropped significantly before returning to the Ping phase. After bringing the receiver close again, the system became stuck, as described earlier.

I hope this is sufficient to outline my issue.