Scientific American Article on 2010 Prius

The car was with 215/45/17 wheels too.

 

Its not that low-pass filters are that expensive, its that low-pass filters with 60 dB of isolation up at cell phone frequencies are fragile and require an expensive housing, both to protect the fragile filters, and for the housing itself to have 60 dB of isolation.

The filters are a combination of ferro-electric capacitors (like EESTOR uses, and can have relative dielectric constants as high as 10000) and ferrites. The ferrites act as inductors at lower frequencies and as disipative devices at higher frequencies.

 

Hi All,

On the idea of attaching the panel to 12 V, there are two issues. First, a bigger heavier 12 V battery would be needed. There is also a switching power supply attached to the 12 V battery, and the panel would just be an antenna for that noise. In the car, the wiring can be colocated, and this is a simple expedient to keep the noise on the wires, and not radiating outside of the car. As soon as one hooks an antenna (solar panel) to the wires, the noise is free to radiate out into free space. What probably saves the day is that the Inverter 12 Volt output is probably already filtered some, the inverter 12 V supply does not operate while the car is off, and the 12 V battery provides some disipation of high frequency signals.

By attaching the blower motor to the panel and a thermostatic control while the car is off, and then back to the inverter fed 12 V supply when the car is on (presumably with a simple relay), allot of these issues are avoided.