31 results about "Line Impedance Stabilization Network" patented technology

An electromagnetic interference self-checking system comprises a signal source, a line impedance stabilizer network (LISN), a coupling and decoupling network (CDN), an impedance stabilization network (ISN) and a receiver, wherein the signal source is used for providing a stabilization signal and is provided with a power supply port; the LISN comprises a power supply port and a radio frequency port and is used for extracting a signal of the power supply port of the LISN and outputting the signal from the radio frequency port of the LISN; the CDN comprises a signal port and a radio frequency port; the CDN is used for coupling a signal of the radio frequency port of the CDN to the signal port of the CDN, outputting the signal and enabling the impedance of a signal transmitting path to be matched; the ISN comprises a signal port and a radio frequency port and is used for extracting a signal of the signal port of the ISN and outputting the signal by the radio frequency port of the ISN; and the receiver is used for measuring the signal strength of each frequency point and reading a value. In addition, the invention provides a use method for an electromagnetic interference testing system.

The invention discloses a measuring device of switch power supply EMI noise source internal impedance that comprises line impedance stabilization network, common mode / differential mode impedance test module, signal generator and spectrum analyzer; power cord is directly input to the line impedance stabilization network, passes the common mode / differential mode impedance test module, and then input to the switch power supply and load to construct a whole power circuit; the signal generator provides a input signal for the common mode / differential mode impedance test module, response signal in the module is detected by the spectrum analyzer. The measuring method of switch power supply EMI noise source internal impedance IA also disclosed. The measuring device and method can measure the all-purpose internal impedance for all kinds of noise source, but also measure the unknown impedance, the accuracy is high and the operation is simple. The measuring method can judge the nature of internal impedance and provide a precondition for designing of EMI filter that is the designing of filter fulfills the impedance matching property of filter.

The invention discloses a coupling and decoupling characteristic determining method of a V-type line impedance stabilization network and belongs to the electromagnetic compatibility conducted emission testing technical field. According to the method, the coupling and decoupling characteristics of the V-type line impedance stabilization network can be calculated and analyzed; and as for a line impedance stabilization network (LISN) of which the component parameters are known, whether the coupling and decoupling characteristics of the LISN satisfy work requirements can be predicted in the aspect of trend. The method can predict and judge the coupling and decoupling characteristics of the LISN according to which a third party metering check unit does not carry out metering, and plays a role of guiding the design and development of novel LISN which can better satisfy requirements.

The invention provides a control system for improving the line impedance stabilizing network low-frequency sampling precision, and the control method thereof. The system comprises a T network unit, a decoupling unit, a communication control unit, an attenuator unit, measuring equipment and measured equipment. The decoupling unit is connected with the T network unit, the communication control unit, the measuring equipment and the measured equipment respectively; and the attenuator unit and the measuring equipment are connected in the forward direction. An inner relay is controlled by the communication control unit to select different sampling and decoupling capacitors in the decoupling unit; and combined with the design of output attenuator unit, the invention provides a convenient and effective scheme for improving the line impedance stabilizing network low-frequency sampling precision in a carrier communication performance test.

The invention discloses a low-voltage orthogonal frequency division multiplexing (OFDM) carrier physical layer communication performance detecting system which is used for detecting emission performance indexes and receiving performance indexes of a low-voltage OFDM carrier physical layer. The detecting system comprises a signal isolation device, a standard carrier sending device, a carrier to be detected sending device, a carrier to be detected receiving device, a standard 50 omega impedance power network, a coupling circuit, two mixers, two adjustable attenuators, a white gaussian noise generator, a line impedance stabilizing network, a programmable logic controller (PLC) demodulation device, an alternating current power meter, a 220V alternating current power source, a signal generator, a network analyzer, a spectrum analyzer, a channel simulator, a signal analyzer and a computer. According to the technical characteristics of low-voltage power line carrier communication of an OFDM modulation mode, the detecting system is capable of conducting detailed test to the main performance indexes of the communication mode, the testing process is speedy, system conformability is high, system manufacturing cost is low, and space and labor cost are saved.

The invention relates to an upward and downward communication test device of a power consumption information collecting terminal. The upward and downward communication test device is mainly formed in a way that a wireless communication test device and a carrier communication test device are respectively connected with a computer system. The wireless communication test device is used for being connected with an upward communication interface of a power consumption information collecting terminal to be tested, and the carrier communication test device is used for being connected with a downward communication interface of the power consumption information collecting terminal to be tested. The wireless communication test device consists of an 8960 communication comprehensive test device, a 9010a signal analysis instrument and a radio frequency switch, and the carrier communication test device consists of two LISN (line impedance stabilization network) power supplies, a receiver, a gating switch, a wireless router, a serial port communication server, a 485 communication switch and a controlled attenuator. The device has the advantages that the detection on the communication capability and the index of a GPRS (general packet radio service) channel and a carrier channel of the power consumption information terminal to be tested is automatically controlled through the computer system, the real-time, accurate and reliable basis is provided for the operation of the power consumption information terminal, and the normal and safe operation of the power consumption information terminal is ensured.

The invention, which belongs to the technical field of the electromagnetic-compatibility conducted emission testing, discloses a method for determining an output impedance and a voltage division coefficient of a V type line impedance stabilization network (LISN). According to the method, for an LISN with known element parameters in a description, the output impedance and voltage division coefficient of the LISN can be obtained based on calculation and analysis; and a tested piece interference voltage value that is measured practically by a receiver during a testing process can be corrected. According to the invention, the method plays an important role in correcting a conducted emission testing result and has guiding significance in improving the conducted emission testing precision.

The invention discloses a V-type line impedance stabilization network isolation determination method, and belongs to the technical field of electromagnetic compatibility conduction emission test. According to the method, isolation of a V-type line impedance stabilization network can be analyzed through calculation. As for the LISN of which the component parameters are known, whether the isolation performance of the LISN meets the working requirements can be predicted and judged by the method. The method has a reference function for measurement and verification of the isolation index of the V-type line impedance stabilization network and has directive significance for design and development and production of the novel LISN of which the performance further meets the requirements.

The invention discloses a power line conduction interference signal detection circuit suitable for field electromagnetic compatibility detection. The power line conduction interference signal detection circuit comprises a power plug, a second-order passive high-pass filter, an attenuator and an analog-digital conversion circuit. The second-order passive high-pass filter and the attenuator can be used for filtering a power fundamental wave signal which is stable 50ohm input impedance in a radio frequency range. When being used for the field electromagnetic compatibility detection, the detection circuit only needs to be connected to a same power socket connected with EUT (equipment under test), the original connection form of an EUT system does not need to be destroyed, and thus an LISN (line impedance stabilization network), an attenuator, a measurement receiver and the like applied in a laboratory environment are omitted.