37 results about "FM transmitter" patented technology

A portable handheld digital content player has an integrated wireless interface, an integrated FM transmitter and an integrated auto on and auto off feature for ease of use in vehicles. The player and associated software on a base content server provide automated broadband wireless content downloads to the player while in a vehicle and transfer of audio to the vehicle stereo via FM band transmission without the use of an accessory. The player integrates an FM scan function to search for a suitable frequency for transmitting within the FM band. The player integrates some PDA-like functionality including personal contact information, appointment calendar, user schedule, email in addition to others.

An accessory for an electronic device detects manipulation of a user input of the device and alters an operating parameter of the accessory in response to the detected manipulation of the device's controls. The accessory is preferably an FM transmitter designed to be coupled to a portable media player such that an audio signal from the player is broadcast by the accessory. The user controls of the player can be used to select a transmission frequency of the accessory. The accessory can also preferably control the display of the device such that an image corresponding to the selected transmission frequency is generated by the accessory and displayed on a screen of the player.

A system for broadcasting audio music and broadcasting lyrics for display and highlighting substantially simultaneously with the occurrence of the lyrics in the accompanying audio music is provided. The system includes <DEL-S DATE="20010410" ID="DEL-S-00001">a<DEL-E ID="DEL-S-00001"> <INS-S DATE="20010410" ID="INS-S-00001">an <INS-E ID="INS-S-00001">audio music source that provides a data output and <DEL-S DATE="20010410" ID="DEL-S-00002">a<DEL-E ID="DEL-S-00002"> <INS-S DATE="20010410" ID="INS-S-00002">an <INS-E ID="INS-S-00002">analog audio signal output. A computer receives the data output by the music source and generates lyric text data and lyric timing commands. A subcarrier generator generates a subcarrier signal carrying the lyric text data and lyric timing commands. An FM transmitter broadcasts a composite signal that combines the analog output of the music source with the subcarrier signal. A lyric display unit receives the composite signal, separates and decodes the subcarrier signal and displays and highlights lyrics according <INS-S DATE="20010410" ID="INS-S-00003">to <INS-E ID="INS-S-00003">the lyric text data and lyric timing commands decoded from the subcarrier signal.

The invention discloses a high-efficiency frequency modulation transmitter, which relates to a transmitting device in the wireless monitoring and control communication technology and comprises a frequency modulation source, a power amplifier, an isolator, a power supply circuit, an antenna and a premodulation filter, wherein the premodulation filter is used for filter processing on PCM (Pulse Code Modulation) signals that are input; the premodulation filter is connected with the frequency modulation source; the power amplifier is a switching power amplifier; the switching power amplifier selects a GaAs device or a GaN device; the grid voltage of the GaAs device or the GaN device is negative electricity offset; the power supply circuit is a power supply and time-sequence control circuit; and the GaAs device or the GaN device is matched with power supply time-sequence. The high-efficiency frequency modulation transmitter reduces power consumption of the transmitter, reduces the heat dissipation requirement of the transmitter, and facilitates the integration and the miniaturization of the transmitter.

Provided is a display system for transmitting FM signals to an external audio system having an FM reception function. The display system includes: a tuner for receiving an RF signal and dividing the RF signal into a video signal and an audio signal; an audio processor for receiving the audio signal from the tuner; an FM detector for searching usable channels or unused channels among FM frequency bands of a reception area and transmitting information on the unused channels; a microprocessor for setting at least one of the unused channels as an available channel, the unused channels being provided from the FM detector; a memory for storing the available channel under control of the microprocessor; and an FM transmitter for receiving the audio signal from the audio processor and transmitting the audio signal over at least one channel selected among the channels stored in the memory under control of the microprocessor.

An FM transmitter which can be easily connected to an existing computer or the like and does not need any troublesome operation is provided. An FM transmitter 100 has an USB device function which can be connected to a PC 400 as an USB host device and comprises a power supply circuit130 which is connected to the power supply pin of an USB socket 410 to generate a predetermined operating voltage when an USB plug 110 is connected to the USB socket 410 of the PC 400, an USB controller 120 for requesting that its own apparatus being a device audio source inputs / outputs data by isochronous transfer in a configuration performed by the PC 400 and a transmission processing section 140 which is actuated by the operating voltage supplied by the power supply circuit 130 and applies FM-modulation to audio data outputted from the PC 400 via the USB socket 410 for transmission.

A wireless audio transmission / reception system is provided. The transmission / reception system includes an FM detector for detecting an occupied channel among radio FM channels, a microprocessor for selecting a using channel that is greatly different in frequency from the detected occupied channel and thus does not interfere therewith, an FM transmitter built in an audio replay system to transmit / receive an audio signal over the using channel, and an external audio system for receiving and outputting the audio signal from the FM transmitter.

The invention relates to the field of digital frequency modulation receivers, and particularly relates to a 433M digital frequency modulation receiver, which comprises a low-noise amplifier and a 433M filter part at the input end, a 392.3M local oscillator source signal circuit part, a frequency mixer and an intermediate frequency filter part, a demodulation secondary frequency reduction circuit part, a single chip micro processing part, and a power control and ground part for the entire circuit diagram. The 433M digital frequency modulation receiver provided by the invention has the advantages that the design is clever; the layout is reasonable; the power consumption is low; the sensitivity is high; the dynamic range is large; and by adopting a 2FSK modulation and demodulation mode, real-time communication with a 433M digital frequency modulation transmitter can be well carried out. The 433M digital frequency modulation receiver has a high scientific research value in the ultra-short wave communication field and has a certain project application value.

A computer port is used to power a wireless transmission of audio signals from a sound card of a personal computer to a home entertainment system for high fidelity sound production. The computer port comprises any computer port that provides power. The computer port is used to power a FM transmitter that is connected to an audio output of a sound card of a personal computer.

A frequency modulation (FM) radio transmitter, such as a cellular telephone, includes an automatic deviation control system to automatically compensate for varying sensitivity of the FM transmitter. The FM transmitter includes a phase lock loop including a controlled oscillator that produces a frequency modulated input signal on an output channel frequency in response to a control input that is applied thereto. A scaler is responsive to the input signal and to at least one scaling content, to scale the input signal based upon the at least one scaling constant and to provide the scaled input signal to the phase lock loop to produce the frequency modulated input signal on the channel frequency. An automatic deviation control system measures the control signal that is applied to the controlled oscillator when tuned to one of the plurality of output channel frequencies and updates at least one of the scaling constants based upon the measured control input, to thereby provide automatic deviation control.

The invention provides a wireless transmitting system and an achievement method of the wireless transmitting system. The wireless transmitting system comprises a tour guide instrument and a tourist tour guide instrument. The tour guide instrument is internally composed of a frequency modulation transmitter and an FM grouping device. The FM grouping device internally comprises a wireless communication module and used for transmitting a compulsively-set frequency signal to the tourist tour guide instrument through the wireless communication module. The tourist tour guide instrument is internally composed of a frequency modulation receiver and a wireless communication module. The wireless communication module in the tourist tour guide instrument is used for receiving the compulsively-set frequency signal transmitted from the FM grouping device to set the corresponding frequency of the frequency modulation receiver. According to the wireless transmitting system and the achievement method, the FM grouping device is additionally arranged in the frequency modulation transmitter used by a tour guide, when the frequency modulation receiver can not receive the signal of the frequency modulation transmitter, the frequency of the frequency modulation transmitter is broadcasted regularly through the wireless communication modules, the frequency of the frequency modulation receiver can be automatically or manually changed, and a tourist can receive the new signal of the frequency modulation transmitter of the tour guide and hear explanations of the tour guide.

An optoelectronic pickup that generates a fluctuating voltage that is analogous to the vibrations of a vibrating body. When utilized with the vibrating body of a musical instrument and amplified and fed to a speaker the musical tones are reproduced at an amplified level. When the signal is fed to an FM transmitter the musical tones can be reproduced in any FM radio receiver. The device makes possible portable electric instruments and "wireless'-electrical instruments, i.e. a guitar that does not require a connecting cord or amplifier. The device anticipates new and unique musical instruments.

The invention discloses a radio system electromagnetic interference test system which is installed in a semi-anechoic chamber and comprises an amplitude modulation transmitter, a frequency modulationtransmitter, a receiver, a first transmitting antenna, a second transmitting antenna and a receiving antenna. The first transmitting antenna is connected with the amplitude modulation transmitter, thesecond transmitting antenna is connected with the frequency modulation transmitter, and the receiving antenna is connected with the receiver. The amplitude modulation transmitter is in communicationconnection with the receiver through the first transmitting antenna and the receiving antenna. The frequency modulation transmitter is in communication connection with the receiver through the secondtransmitting antenna and the receiving antenna. The amplitude modulation transmitter is installed at a first preset distance of the frequency modulation transmitter, and the receiving antenna is arranged at a position where the vertical distance between the amplitude modulation transmitter and the frequency modulation transmitter is a second preset distance. The invention also discloses a radio system electromagnetic interference test method, which can effectively eliminate other electromagnetic interferences in the space and reduce the hardware requirements of the test equipment, thereby effectively reducing the test difficulty and improving the accuracy of the test result.

The invention discloses a high-low pass filter for a high-power frequency modulation transmitter. The high-low pass filter comprises a filter bank and a selection circuit connected with the filter bank and used for filter frequency selection. The filter bank comprises a low-pass filter bank and a high-pass filter bank which are connected in series, and each of the low-pass filter bank and the high-pass filter bank comprises a plurality of low-pass filters which are connected in parallel and a plurality of high-pass filters which are connected in parallel. The selection circuit can select at least one low-pass filter or at least one high-pass filter to work or select one low-pass filter and one high-pass filter to work at the same time; wherein the selection circuit is provided with a relay, the relay is connected with a TTL drive circuit, the TTL drive circuit is connected with an MCU control unit, and the MCU control unit controls the relay to work through the TTL drive circuit. According to the high-low pass filter, the problems of low tuning speed and large error of a filter in the prior art are solved.

There is disclosed a multi-unit communication system having, at each unit, both an FM receiver and a FM transmitter as well as a digital receiver and transmitter. The primary communication of an information signal from the system to a plurality of mobile hand held transceivers is through the FM transmitters. The digital receiver and transmitter provides a back channel to provide communication of the message throughout the set of units to assure that the information is available at each unit for conversion from digital to analog form so as to be broadcast by the FM transmitter.

Digital values representing an audio signal are formed in a FM transmitter. The deviation of the amplitude of the audio signal as represented by the digital values, from a reference amplitude level, is measured. The audio signal is filtered based on the deviation measured by processing the digital values, with the filtering designed to filter different frequency components of the audio signal with different respective magnitudes. Another set of digital values representing the filtered audio signal is generated, and used to frequency modulate a carrier signal to generate a FM signal. Over-modulation of the FM signal is thereby controlled.

The invention discloses a 2.4-2.48 GHz / 50W linear frequency modulation transmitter. The transmitter comprises a linear frequency modulation source unit, a solid-state power amplifier unit, a control unit, a power supply unit and an air cooling unit, wherein the signal input end of the control unit is connected with a communication information source; the output end of the control unit is connectedwith the input ends of the linear frequency modulation source unit, the solid-state power amplifier unit and the air cooling unit; the output end of the linear frequency modulation source unit is connected with the input end of the solid-state power amplifier unit; the input end of the power unit is connected with the power input end; and the output end of the power unit is connected with the control unit and the air cooling unit to supply power to the system. The transmitter has the advantages of reasonable design, high efficiency, reliable performance and the like.

An AM / FM / SW receiver coupled with an FM transmitter for personal multimedia players for both listening and recording uses innovative antenna and shielding design and placement to raise the signal-to-noise ratio of the intended broadcast content to a level which is acceptable to the listener.

The invention discloses a frequency modulation transmitter device based on Bluetooth communication. The mobile phone comprises a built-in Bluetooth communication transceiving module of the mobile phone, the invention discloses an HC-05 Bluetooth communication transceiver module. The invention discloses an STC89C52 single-chip microcomputer signal processing circuit. Power supply electronic switchcontrol circuit, third-stage power amplifier, the system comprises a final-stage power amplifier, a first-stage power amplifier, a second-stage power amplifier, an automatic gain AGC control circuit,a delay AGC control circuit, an MIC audio amplifier or external audio signal, a voltage-controlled oscillation and frequency modulation circuit, an OP07 active amplification circuit, an MC145152-2 frequency division and phase discrimination circuit and an MC12022AP prescaler, wherein the MIC audio amplifier or the external audio signal outputs a signal to the voltage-controlled oscillation and frequency modulation circuit; the voltage-controlled oscillation and frequency modulation circuit outputs signals to the MC12022AP prescaler and the first-stage power amplifier; and the MC12022AP prescaler outputs a signal to the MC145152-2 frequency division and phase discrimination circuit.

The invention discloses a terminal FM function testing device, method and system. The testing device comprises a shielding space, a testing host, a tested terminal, an earphone antenna and a pluralityof FM transmitters. The testing host, a tested terminal, an earphone antenna and a plurality of FM transmitters are all arranged in the shielding space, wherein the tested terminal and the FM transmitters are electrically connected with the testing host, and the earphone antenna is electrically connected with the tested terminal; each FM transmitter is used for transmitting FM signals; the testedterminal is used for receiving the FM signals; and the testing host is used for setting emission parameters of the plurality of FM emitters according to the testing case, controlling the tested terminal to search FM signals and / or switch channels of the currently received the FM signals, and detecting an FM function of the tested terminal according to the test case and FM information of the FM signals received by the tested terminal. According to the invention, automatic test of channel searching and channel switching functions in the FM function of the terminal can be realized, so that the test of the FM function of the terminal is enriched.

The invention provides an eight-channel frequency modulation transmitting all-in-one machine, which comprises a case, and is characterized in that eight input ports, a decoding unit, an eight-channeladjusting plate, a synthesizer, a power amplifier, a power supply, a switch, a video interface and an antenna interface are arranged in the case; the decoding unit comprises an audio decoder group andan audio-video decoder; the input ports are connected with the audio decoder group or the audio-video decoder, the audio decoder group or the audio-video decoder is respectively connected with the eight-channel adjusting plate, the eight-channel adjusting plate integrates the eight-channel FM modulator and the eight-path radio frequency device; the eight-channel adjusting plate is externally connected with the synthesizer; the synthesizer is connected with the power amplifier; the power amplifier is connected with the antenna interface; and the audio and video decoder decodes the audio part,and the video part is directly output to the video interface. The eight-channel frequency modulation transmitting all-in-one machine is reasonable in structural design, and compared with a traditionalfrequency modulation transmitter, the all-in-one machine integrates eight channels in one case, so that audio / audio / video information of the eight channels can be received, processed and sent at thesame time, energy consumption is reduced, energy is saved, and the environment is protected.

A transmitter for a car includes a cable, a housing and a mounting member. The housing includes therein a magnetic member, a circuit board, a Bluetooth module, an FM transmitting module, and a control module that are electrically connected to the circuit board. The cable is electrically connected to the circuit board. The mounting member is rotatable with respect to the housing. After the Bluetooth module is connected to the electronic device, the control module is used to receive an audio file transmitted from the electronic device through the Bluetooth module, and process the audio file into audio signals. The control module is further used to transmit the audio signals to the FM transmitting module, and the FM transmitting module is used to transmit the audio signals to a car radio of the car.

The invention discloses a data security signal transmission system of the Internet of Things, which includes a photoelectric conversion amplifier circuit, a voltage comparison circuit, a sine wave oscillation circuit and a frequency modulation transmission circuit. The signal is sampled and its optical power is converted into a fiber optic voltage. The voltage comparison circuit compares the fiber optic voltage with the upper limit of the standard voltage and the lower limit of the standard voltage. The power detection signal is obtained, the sine wave oscillation circuit determines the frequency of the sine wave modulation signal according to the positive and negative of the power detection signal, and the frequency modulation transmitting circuit performs FM modulation on the sine wave modulation signal to obtain the power conditioning signal, and transmits the power conditioning signal to the radio and television material Network power monitoring and control terminal, so that the radio and television Internet of Things power monitoring and control terminal can adjust the optical power of the radio and television Internet of Things optical transmitter.

The invention relates to a frequency modulation transmitter and electronic equipment, and relates to the technical field of communication. The frequency modulation transmitter comprises: a modulation circuit which comprises a signal acquisition unit and a signal generation unit, wherein the signal acquisition unit is used for acquiring an analog signal, and the signal generation unit is used for generating a bias voltage and superposing the bias voltage and the analog signal to output an analog modulation signal; an oscillation circuit which comprises a first capacitor and a tunnel diode, wherein the first capacitor and the tunnel diode are used for forming an oscillation loop, and the oscillation loop is used for accessing an analog modulation signal and converting the analog modulation signal into a radio frequency carrier signal; and an antenna which is coupled to the oscillation circuit and is used for transmitting the radio frequency carrier signal. The power consumption of the frequency modulation transmitter can be reduced to a micro-watt level.

The invention discloses a frequency modulation transmitting device. The device comprises a single-chip microcomputer module, an FPGA module, an analog-to-digital conversion module, a phase discrimination module, a loop filtering module and a voltage controlled oscillation module. The single-chip microcomputer module performs frequency setting on the phase discrimination module according to a preset working mode to adjust the input voltage of the phase discrimination module acting on the coarse tuning end of the voltage controlled oscillation module, so that the output signal of the voltage controlled oscillation module is the same as the setting value of the phase discrimination module. The FPGA module performs high-speed sampling on the received external data signals and controls the input voltage of the digital-to-analog conversion module according to the frequency offset control word of the code rate corresponding to the received external data signal. The digital-to-analog conversion module controls the input voltage of the digital conversion module acting on the fine tuning end of the voltage controlled oscillation module according to the current input voltage, so that the precision of the output signal of the voltage controlled oscillation module reaches a preset value. According to the frequency modulation transmitting device, coarse tuning and fine tuning of the output signal of the voltage controlled oscillation module is realized, and the effects that the output signal frequency of the transmitting device is stable, the spectrum purity is high, and the resonance clutter suppression degree is high are achieved.

The invention provides a device for wirelessly detecting abnormal sound of a vehicle, and the device comprises a piezoelectric ceramic sensor which converts the received vibration into an electric signal; a clamping component installed on any part, suspected to have abnormal sound, of the vehicle, wherein the piezoelectric ceramic sensor is arranged in the clamping component; a FM transmitter used for receiving the electric signal and amplifying the electric signal, wherein the FM transmitter outputs the amplified electric signal as an audio signal, and the FM transmitter is fixed on the clamping part; and a vehicle-mounted radio used for receiving the audio signal and judging the part where the abnormal sound is located according to the frequency corresponding to the abnormal sound of the vehicle-mounted radio. The problem that an existing wired detection device needs to pull a lot of long wires into a cab and is unsafe is solved. Meanwhile, the problem of misjudgment caused by the fact that various abnormal sounds exist at the same time and the abnormal sounds fed back by a maintainer and a vehicle owner are not from the same source due to the fact that the used earphone is operated by a single person is solved.

This invention provides an automatic controlled FM transmitting device including a FM transmitter and an outer host, in which, a slave control part is connected with the outer host, the FM transmitter includes a slave controller, a FM modulator and an emission antenna, the input of the slave controller is connected with a primary controller, the output of the slave controller is connected with the FM modulator, the output of the FM modulator is connected to the emission antenna. A method includes: the slave controller judges if there is sound source input from the exterior host, if there is sound source input, the supply of the FM modulator is turned on to supply to the FM modulator to emit modulation carrier signals, when there is not sound source input, the supply is cut off after timing a period of time to shut the emitter and stop the emission of FM carrier signals.