Patent Application
20050277384
1. Field of the Invention
The present invention relates to a FM stereo modulator. More particularly, it relates to a FM stereo transmitter that converts audio signal into FM signal then transmits the FM signal through an antenna at certain user-selectable frequencies.
2. Description of the Related Art
With the fast development and advancement in consumer electronics, a variety of music players, such as portable MP3 players, MD players, and CD players, have been developed and have gained popularity in the marketplace. Users of these portable music playing devices commonly enjoy the music with an earphone. Due to lack of interface between the stereo system and the portable device, it is not possible to use a portable music playing device with an auto stereo system unless a cassette adapter is used. Moreover, it is difficult to find auto stereo systems with such cassette features these days. Consequently, it is very inconvenient, if not impossible, to use a portable music playing device with an auto stereo system in an automobile.
In light of the above, the object of the present invention is to provide a convenient link between the portable music playing device and the stereo system by converting the audio output from the portable music playing device to FM stereo signal receivable by the FM tuner in a stereo system. We call the device providing such a link “FM Stereo Modulator”.
To achieve this and other objects of the present invention, the FM stereo modulator comprises an enclosure, a power connector, a music source connector, and a FM stereo modulating circuit.
The casings of the enclosure form a cavity to house the FM stereo modulating circuit and contacts (both positive and negative). A cable with the music source connector is extended outside of this enclosure. When the contacts are connected to a power source and the music source connector is inserted into the audio output terminal of a portable music playing device, the FM stereo modulator receives both the needed operating electricity and audio signal. Then the FM stereo modulator through the FM stereo modulating circuit converts the audio signal received into FM stereo signal and transmits it through the antenna at one of the 4 user selected frequencies.
To illustrate the abovementioned functions and features of the present invention, the preferred embodiments of the FM stereo modulator according to the present invention are described in detail below:
A FM stereo modulator modulates the audio output signal of a portable music playing device, for example, a MP3 player, into FM stereo signal that is receivable by an automobile FM tuner. Referring to
The enclosure 1 is a hollow plastic shell shaped like a pistol, having a front side 11 and a rear side 12.
The power connector 2 is integral with the enclosure and forwardly extended from the front side 11 of the enclosure 1, comprising a connecting tip 21 and a spring contact 22 for connection to the electric socket for cigarette lighter in an automobile or similar power output socket that may be found in a ship, airplane, office, or house to obtain the necessary working voltage.
The music source connector 3, linked to the enclosure 1 by a cable, is connectable to the audio output terminal of a portable music player. The music source connector 3 can be a 3.5 mm earphone plug or a 2.5 mm earphone plug. The cable of the music source connector 3 has the function of an antenna.
The FM modulating circuit 4, as shown in
In conclusion, the present invention ‘FM stereo modulator’ described above can achieve its intended objectives. Additionally, it has not been disclosed in any publications or available in public.
Although a particular embodiment of the invention has been described in detail for illustration purposes, various modifications and enhancements may be made without departing from the spirit and scope of this invention.
