The main task of the pulse sensors is to ensure that the ignition of the fuel is synchronized with the piston in cylinders. History of a pulse sensor
History of a pulse sensor
Incontact ignition systems, of which pulse sensors are an integral part, were widely used in cars at the beginning of the eighties of the last century. Until then, they were actively used in motor cycle and boat motors. The non-contact ignition engine with the allocator has been installed for a relatively short period of time, approximately from the beginning to the end of the 1980s. Since the beginning of the injection engine, they have been replaced by microprocessor systems of ignition control.
The role of a pulse sensor in the ignition system
Impulse sensor is one of the key components of the contactless ignition system. The sensor is installed in the immediate vicinity of the drive valve and tracks the speed of its rotation. The faster the shaft moves, the more often the sensor transmits low voltage electrical impulses to the switch that generates the trigger signals for the initial coil of the ignition coil.
Several pulse sensors apply to the current engine monitoring system. They differ in appearance, but not by design.
Irrespective of the speed of the shaft, the mixture in the cylinders shall be ignigated when needed, that is, when the piston approaches the upper dead point.
Device and operating principle of a pulse sensor
The absolute majority of the pulse sensors used in the ignition systems are of three types-induction, optical, and magnetoelectric (based on Hall effect). The latter are so common that the term "Hall sensor" is often used as a general definition of pulse generators, which is not quite correct.
For the first time, Russian motorists collied with the Hall sensor in the VAZ 2105 ignition control system.
The operating principle of the Hall sensor is based on the change of conductivity of special semiconductor material under the influence of the permanent magnetic field. As a rule, the source of the field (permanent magnet) and the semiconductor element are fixed and separated by a curtains with aperture. The curator is secured to the shaft of the allocator and is rotated with it. The magnetic field is interrupted when the surfacing curtain is opposite the semiconductor. The electrical impulses are generated by alternating periods of availability and absence of the field.
The operation of the induction generator of pulses, as clear from the name, is based on the phenomenon of electromagnetic induction. The sensor consists of a permanent electromagnet with coils and a jagged disc. When the disc is rotated, the magnetic field is closed either through the tooth or through the front of the disc. Thus, the magnetic flow through the winding is increasing and decreasing.
The Hall effect was used in the principle of the action of rocket engines for long-range space aircraft
Optical pulses sensors are operated by rupture of the infrared light seal that is directed to the photo ranger.
Considerations for the operation of pulse sensors
Like any electronic component that does not have moving parts, the pulse sensor itself is practically vetted. If there are problems with the ignition system, its diagnostics should last. To ensure the reliable operation of the pulse generator, it is sufficient to monitor the purity and integrity of the connector that falls on it. If the suspicion of the malfunctioning of the pulse sensor arises, it is enough to add a voltmeter and pull the shaft. The absence of voltage swings at the outlet will clearly indicate the failure of the details.
