Technician A says that most fuel injection systems use the PCM to control the pulsing of the fuel injectors. Technician B says that most fuel injection systems use the PCM to control the operation of the fuel pump relay. Which technician is correct?

The correct answer is: Both Techs PCM.

Explanation:

The fuel control system electronically uses a completely different mechanism for pressure control. In this system, the PCM controls the rail pressure by modulating the activation of the pump, that is to say that it activates and deactivates the pump to maintain a pressure level according to the load in which the engine is, for this you need to know exactly the fuel pressure and its temperature, so it will incorporate 2 sensors for this purpose.

Basically, it is a system that activates and deactivates the fuel pump with the help of a DRIVER module, which directly controls the PCM, this module is called FPDM, this module controls the voltage and current flowing through the pump.

To know the pressure of the rail, a pressure sensor is used which is in charge of permanently sending a level of tension that changes with the pressure, this sensor is called FRP, while measuring the pressure of the rail is evaluated the fuel temperature in the rail, for this a sensor of the NTC type (Negative temperature coefficient), called EFT, is incorporated.

All this information is used to correctly calculate the pressure and thus have an efficient operation, reaching even lower levels of contamination.

Mechanically, the system incorporates a Damper, to avoid pressure peaks every time the injectors are opened and closed.

sound is invisible, but sometimes we can feel it. when a kettle-drum is thumped with a stick that time the tight drum skin moving up and down very quickly for some time and then it pumped sound waves into the air. loudspeakers also work in a similar manner.

components of a speaker:

electromagnet

in order to translate an electrical signal into an audible sound, an electromagnet is used in looudspeakers

  suspension

suspension is used to   center the voice coil in the gap of the magnet and it exerts a restoring force to keep it there. suspension is used to limits the maximum mechanical excursion of the diaphragm and voice coil.

voice coil

voice coil is a coil of wire which is attached to the apex of a loudspeaker cone. it provides the motive force to the cone by the reaction of a magnetic field to the current passing through it.

cone

in a   loudspeaker, a   thin, semi-rigid membrane attached to the voice coil, which moves in a magnetic gap due to which it vibrates   and produced sound. it is known as diaphragm and it can also be called a cone, though not all speaker diaphragms are cone-shaped.

surround

surround is also known as front suspension. surround is used to join the cone to the chassis. together with the suspension it controls the cone excursion, and it is also used to   determine how energy which is   travelling through the cone is absorbed, and how the speaker limits when it reaches the ends of its travel.

dustcap

dustcap is used to protect the voice coil from dust and dirt. it is a part of the cone.

how speaker work

the outer part of the cone is fastened to the outer part of the loudspeaker's circular metal rim. the inner part is fixed to   voice coil that sits just in front of a permanent magnet . when loudspeaker is hooked up to a stereo, electrical signals feed through the speaker cables into the coil. it will convert the coil into an electromagnet magnet . when electricity flows back and forth in the cables, the electromagnet either repels or attract the permanent magnet. this moves the coil back and forth, and it pull and push the loudspeaker cone. like a drum skin vibrating back and forth, the moving cone pumps sounds out into the air.in this way loudspeakers works.

answer; private store;