Ignition Interference Research Articles

Search on Ignition Interference Prevention of Vehicle Safety System

Basic on the problem that the electromagnetic environment in vehicles which formed at the moment of ignition will cause interference to the stability and reliability of vehicle safety system, the paper takes vehicle fire protection system as the research object, and analyzes the interference mechanism and harmfulness through the simulation experiments. Finally uses the related software design and some prevention measures for electromagnetic interference such as shielding, grounding to protect the system, then through experiment to verify that it’s scientific and reasonable.

Electromagnetic compatibility in the automotive environment

Modern automotive vehicles depend increasingly on sophisticated electronic control systems to enhance driver comfort and vehicle safety. Radiated immunity testing of cars to field strength levels of the order of 50 V m/sup -1/ has been an important part of the vehicle development process for the last decade because of the harsh environment encountered and the safety-related nature of the control systems. The article reviews the way in which electromagnetic compatibility has been approached by the automotive industry for the last 40 years starting with legislation to control ignition interference to the development of a draft product-specific directive covering all aspects of automotive EMC which will ensure that the automotive industry does not fall within the scope of 89/336/EEC. >

An evaluation of a sideband diversity technique for data transmission on the forward path in a mobile radio area coverage scheme

The technique of sideband diversity has been applied to a quasi-synchronous amplitude modulated area coverage scheme for mobile radio, primarily to improve the error performance ofmedium-speed data transmissions to vehicles. Results are presented for commercial voice frequency modems using f.s.k. modulation at 1200 baud. Improvements in error performance of between one and two orders of magnitude have been measured. The residual errors after sideband diversity had been applied were heavily dependent upon ignition interference.

Distribution and Frequency Dependence of Unintentionally Generated Man-Made VHF/UHF Noise in Metropolitan Areas. Part II-Theory

The frequency and range dependence of unintentionally generated man-made VHF/UHF noise in metropolitan areas may be interpreted by assuming that it is composed of random impulses which have been attenuated by propagation over irregular terrain. Man-made noise power per cycle of bandwidth measured for the frequency interval 150 to 500 Mc/s is shown to possess decrements of -10.4 dB/decade change in frequency and -17.9 dB/decade change in range. Theoretical computations of the frequency and range decrements based on a random impulse, irregular terrain model yield frequency and range decrements of -11.1 to -11.3 dB/frequency decade and -17.3 to -18.3 dB/range decade which are in good agreement with the measured results. Comparison of the measured VHF/UHF decrements for unintentionally generated man-made noise in urban and suburban areas with those derived from data which were predominantly of automotive ignition origin supports the conclusion that automotive ignition interference is the major source of man-made noise at these frequencies.

Automotive Ignition Interference

The basic mechanism of electromagnetic interference generated by automotive ignition systems and the nature of this interference are discussed. Various methods of ignition interference suppression are reviewed. The mechanism of interference suppression by ferrite core ignition cable is explained from the magnetic core loss mechanism point of view.

Ignition interference to UHF communication systems

Some quantitative measurements on vehicular ignition noise are reported in terms of the spectral density of radiated power in the vicinity of 900 Mc, to assist in predicting the amount of interference which must be considered in siting microwave communication systems. The median radiated power of the ignition pulses was determined to be −12 dbm and −22 dbm/Mc bandwidth for trucks and passenger cars respectively. Conventional suppression techniques, normally effective at lower frequencies, were found to have no effect. Polarization of the receiving antenna also had no statistical effect. The effects of such interference on the FM receivers and multiplex equipment of a troposcatter communication link were also evaluated. The pulses were audible whenever their received level exceeded the desired signal level.

Measurement and suppression of VHF radio interference caused by motorcycles and motor cars

The problem of ignition interference and its reduction has been emphasized in Europe, due to the simultaneous growth in both the number of motor vehicles, and in the number of FM and TV receivers. The paper reports the results of a large number of interference measurements made on automobiles and motorcycles. The data include the effects of various suppression schemes. As a result of these measurements, and taking into account existing European standards, a draft of an international standard was prepared for submittal to CISPR. This proposed standard covers both methods of measurement and limits.

Radio interference from ignition systems

The paper records the results of some tests made in the United States to compare results obtained with American, German and British radio-interference measuring sets when measuring the interference radiated by the ignition systems of motor vehicles. The tests show the close agreement between the results obtained when using the various national measuring sets and confirm the reliability and consistency of measuring equipment conforming to the specification of the International Committee on Radio Interference (C.I.S.P.R.). They also attempt to establish a relationship between the results of peak and quasi-peak measurements.The paper also tabulates and discusses the test conditions specified in the various countries and quotes the limits of ignition interference recommended or statutory in the countries concerned. A direct comparison of these limits, which is made possible by these measurements, suggests that the existing and proposed requirements of other countries are more onerous than those of the United Kingdom.

Ignition interference with television reception

The spark-ignition circuit of the internal-combustion engine is the most widespread source of interference to short-wave radio and television services. This paper reviews the progress made in the measurement of the interference producing radiation and the development of remedial measures summarized in the relevant British Standards and Codes of Practice. The regulations for the control of ignition interference recently introduced by the Postmaster General are described and their implications discussed. The design, construction, and efficacy of suppression equipment, in particular suppression resistors for insertion in the high-tension part of the ignition circuit, are described in some detail.The possible effect of resistors on engine performance is discussed and the results of tests under controlled conditions indicating negligible effect are given.The results of extensive measurements of the magnitude of ignition interference on passenger cars and commercial vehicles are analysed and assessed in relatio...

Ignition Interference with Television Reception

The spark-ignition circuit of the internal-combustion engine is the most widespread source of interference to short-wave radio and television services. This paper reviews the progress made in the measurement of the interference producing radiation and the development of remedial measures summarized in the relevant British Standards and Codes of Practice. The regulations for the control of ignition interference recently introduced by the Postmaster General are described and their implications discussed. The design, construction, and efficacy of suppression equipment, in particular suppression resistors for insertion in the high-tension part of the ignition circuit, are described in some detail. The possible effect of resistors on engine performance is discussed and the results of tests under controlled conditions indicating negligible effect are given. The results of extensive measurements of the magnitude of ignition interference on passenger cars and commercial vehicles are analysed and assessed in relation to the permissible limit imposed by the regulations. Estimates are given of the percentage of vehicles complying with the regulations by the adoption of the various methods of resistor suppression. The MS. of this paper was received at the Institution on 10th July 1952, and in its revised form, as accepted by the Council for publication, on 1st January 1953. For the Minutes of the meeting in London, on 10th February 1953, at which this paper was presented, see p. 90.

Transient Response of an FM Receiver

This paper develops various formulas for the response of an FM receiver to signal or noise input voltages of arbitrary form. The principal object in view is to obtain a more complete understanding of how an FM receiver responds to transient voltages, such as those arising from ignition interference, but the more general aspects of the theory have other applications as well. In particular, general formulas are given for the response of a linear circuit to an applied voltage, or current, of variable frequency. The Fourier transforms, or frequency spectra, of the response, and the envelope thereof, are determined.

A Broadcast Receiver for Use in Automobiles

The purpose of this paper is to present several important features affecting the design of a broadcast receiver for use in automobiles. The design of the receiver is carried along step by step with special reference to (1) type of collector, (2) ignition shielding, (3) electrical characteristics of receiver, (4) physical structure of receiver, (5) power supply. From measurements made on an experimental receiver installed in an automobile the ignition interference is found to be greatest at the higher frequencies in the tuning range. Observations made during a road test of the receiver indicate a normal service range of from 50 to 100 miles on such stations as WJZ, WOR, and WEAF. The severe fluctuation of the signal encountered in travel through hilly country indicates the desirability of some form of automatic volume control.