Building a Wireless Power Transmitter base for Qi compliance

mister_rf, Sun Jun 28 2015, 05:09PM

This project consists of a single-channel transmitter and power supply side receiver and associated magnetics.
The project implement a method of contactless power transfer from a Base Station to a Mobile Device, which is based on near field magnetic induction between coils.

1435510565 4465 FT1630 Functional Diagram

I have followed the Texas Instruments recommended application design.
The transmitter system use the following sub modules:
Power Transmitter Manager (bq500410)

1435510977 4465 FT1630 Bq500410

Buck regulator + Low Power Supervisor (TPS54231 + MSP430G2101)

1435510565 4465 FT1630 Power Ctrl

RF Power amplifiers (TPS28225 + TS5A1066 + CDS17308)

1435510565 4465 FT1630 Power Amplif


1435510565 4465 FT1630 Amplf2   3


1435510565 4465 FT1630 Current  Amplif




The transmitter requires single 12-V at 0.5 a power supply to operate.
Receiver output voltage of 5 V up to 1 A, so the the transmitter may delivers 5 Watt power into.
The LEDs indicates power transfer state and buzzer indicates start of power transfer.
The circuit operation at frequencies in the 100…205 kHz range. The bq500410 use a simple communications protocol enabling the Mobile Device to take full control of the power transfer.
By using three coils the circuit support arbitrary placement of the Mobile Device on the surface of a Base Station that can provide power through any location of that surface. Very low stand-by power achievable by using the MSP430G2101 as Low Power Supervisor (standby power of <90mW).

3D simulation of the PCB

1435510977 4465 FT1630 Mrf Wtx1f



1435510977 4465 FT1630 Mrf Wtx1b



The real PCB.

1435510977 4465 FT1630 Wireless Ctrl2a


To be continued.
Re: Building a Wireless Power Transmitter base for Qi compliance
Experimentonomen, Mon Jun 29 2015, 04:02PM

You better make it qi compatible so that it actually works with all devices.
Re: Building a Wireless Power Transmitter base for Qi compliance
mister_rf, Mon Jun 29 2015, 06:06PM

The bq500410A is a WPC compliant digital wireless power controller, (actually is WPC 1.1) that integrates all functions required to control wireless power transfer to any Qi-compliant receivers.
Thanks, the title has been changed in order to contain these details. shades
Re: Building a Wireless Power Transmitter base for Qi compliance
mister_rf, Sat Jul 11 2015, 09:33AM

This power transmitter use the WPC design A6 and contains three primary coils.
In order to achieve higher system efficiency, the transmitter system detect a best coupling case between receiver coil and any transmitter coils in the array, and selecting the appropriate coil based on the perceived strength of the coupling.
The overlapping scheme guarantees that there are not ‘dead spots’ in the defined area.
This is meant to ensure that a device can be placed anywhere on the defined area and it will start to charge.
For the moment I have prepared some individual coils in order to do some tests.


1436606996 4465 FT1630 Bq500410 V1


1436606996 4465 FT1630 Bq500410 V2


Later on I will change the layout for a dedicated three coils design setup.


1436606996 4465 FT1630 Coils Setup