
In order to transfer electricity to movable, in particular rotating parts, you usually use slip rings. However, their contacts are subject to waste, do not hold any long and are quite expensive.
This power module is completely contactless similarly to the Qi charger data for smartphones: The transmitboard is supplied with a voltage of 5 to 12 volts and generates a high-frequency magnetic field with the aid of the integrated circuit XKT 412 in the coil printed on the board.

Conflict information on the performance and supply voltage
This in turn induces an alternating current in the likewise printed coil of the reception board, with which a circuit can be supplied after equalization and, if necessary, stabilization. Up to 10W power can thus be transferred over a distance of up to 90 mm. At rough distance, the energy yield decreases significantly to the reception board.
On the Aliexpress page there is, however, for the supply voltage and performance opposing information: times is of 12 V, sometimes from 14 v the speech. In the text it is called 12 watts of power, in the circuit diagram only 10W. A short test revealed that the transmission board with 12 volts is easily working in continuous operation, but only a few seconds over seconds.
A reception board with four white luminous power LEDs is included. After removing the light-emitting diodes you can use the voltage to two lot points. The rotation of the reception board does not affect the energy transfer. When taking the maximum performance, however, you should provide a good volume of the broadcasting board, as it expects it to be stronger.
The board parches is available for just under 8 euros.