Methods and devices for inductive coupling into power lines
An electronic device is provided, including a housing having a back surface. The device includes a rechargeable battery, a capacitor, an inductor coil connected to the capacitor, the inductor coil being disposed around an axis oriented perpendicular to the back surface, a rectifier circuit connected to the inductor coil to output a direct current (DC), a DC-DC converter connected to the rectifier circuit, configured to trickle charge the battery with current received from the rectifier circuit, a test load switchably connected to the DC-DC converter, and a feedback circuit configured to detect a voltage level of the test load and provide an indication of the voltage level.
1. A method of inductive charging an electronic device using a powerline disposed in a premises, comprising:
detecting, with the electronic device, a magnetic field generated by current in the powerline within a wall of the premises at a first location;
determining a power generation level that the electronic device can achieve from inductive charging at the first location;
moving the electronic device to a second location;
providing, while the electronic device is moving, feedback indicating a level of power generation achievable via induction from the powerline;
attaching the electronic device to the wall at a position on the wall where the indicated level of power generation is above a threshold value; and
trickle-charging a rechargeable battery in the device using an inductive charging power circuit disposed in the electronic device.
2. The method of claim 1 , wherein determining the power generation level comprises:
disconnecting the battery from the inductive charging power circuit;
connecting the inductive charging power circuit to a known load;
measuring a voltage across the load; and
determining the power generation level based on the voltage drop.
3. The method of claim 1 , wherein providing the feedback indicating the level power generation comprises illuminating a plurality of light emitting diodes in varying colors, including a first color that indicates a low power generation level and a second color that indicates a high power generation level.
4. The method of claim 1 , wherein providing feedback indicating the level of power generation comprises transmitting a digitally encoded signal to an external computing device, the digitally encoded signal indicating a value representing an amount of the generated power.
5. The method of claim 1 , wherein providing feedback indicating the level of power generation comprises providing a range of audible sounds including a first audible sound that indicates a low power generation level and a second audible sound that indicates a high power generation level.