STEVAL-WBC2TX50 Evaluation Board Power Issue

[EE2024]

Hi,

I have a STEVAL-WBC2TX50 Evaluation Board, and I am having issue with input power. Whenever I supply Vin to the board, it takes a lot of current at low Vin. Can you help me solving this problem?

Thank you!

[Peter BENSCH]

Welcome @EE2024, to the community!

The STEVAL-WBC2TX50 is a power transmitter that can transmit up to 50W, which results in corresponding currents. What exactly do you mean by ‘a lot of current’ and at what voltage does this occur?

Regards
/Peter

[EE2024]

Thanks for the reply. I mean that I supplied about 12.5 V to the transmitter board, and it took about 120mA current (measured by the power supply), and green LED was blinking, which showed that power was being transmitted wirelessly with a load at the receiver side. However, when I tried the same thing after some time with some load at the receiver side, the STWBC2 IC got heated and I removed the power supply immediately. After some time, I powered up the board, and the board drained more current (~1.5 A) at 3.3 V. This is my concern that how can I supply 12.5V to the board because the board is draining a high current even at low Vin.

[willzhou]

Hi

Due to STEVAL-WBC2TX50 need to ping to find there is RX or not, so it will draw current in short time. Normal it works on 5V or 9V at the initial phase.

also you can check the user manual here.  Also we have GUI, if you can post the picture of GUI data, it will be better for us to get more information.

• UM3231: https://www.st.com/resource/en/user_manual/um3231-stevalwbc2tx50-wireless-power-transmitter-evaluation-board-stmicroelectronics.pdf
• STSW-WBC2FW: https://www.st.com/en/embedded-software/stsw-wbc2fw.html
• STSW-WBC2STUDIO: https://www.st.com/en/embedded-software/stsw-wbc2studio.html

[EE2024]

Thanks for the prompt reply. I tried to connect the board to the GUI, but GUI showed that "no connection". Try again. When I tried to supply the required 5V to the board with a receiver, it asked for a more current ( > 2 A). Thus, I removed the power supply for a safe side. My problem is that I cannot supply 5V to the board. If I want to supply 5V, I will need to allow my power supply to draw more current for the board, and this can cause safety issue with my power supply.  

[willzhou]

Hi 

Seem the board is abnormal,  it will not draw 2A when power supply is 5V. Do you put any RX or coils on TX?

How about you check VIN/Vbridge test point on the board based on sch file.

https://www.st.com/resource/en/schematic_pack/steval-wbc2tx50-schematic.pdf

[EE2024]

Yes, you are right, this behaviour is abnormal. I did not put receiver on the Tx side.

Thanks for sharing the schematic. I have read it. I hope I will find something useful.

If my board does not work despite all possible solutions, can you recommend me how can I buy new one?

Thanks for your assistance. 

[willzhou]

Hi 

You can find here

STEVAL-WBC2TX50 - eStore - STMicroelectronics

STEVAL-WBC2TX70 - eStore - STMicroelectronics

[EE2024]

Thanks for sharing the list. Does Stm have evaluation board for 15 W applications?

[willzhou · Accepted solution]

Hi 

For TX we have 5W as below,

15W TX evaluation board is not ready on st website, but it is used for big volume customer.

• DB5000Qi-compatible wireless power transmitter evaluation board for 5 W application based on STWBC86
• AN5961Wireless power transfer coil design
• UM3161Getting started with the STEVAL-WBC86TX wireless power transmitter evaluation board for up to 5 W Qi-BPP applications

STEVAL-WBC86TX

Qi-compatible wireless power transmitter evaluation board for 5 W application based on STWBC86