View The Full Version : Duty Cycle the injectors:this unknown
Caio guys I decided to collect a p? for info about the topic of the title thread because to tell you the truth? I tried "a p? around" but what I have found out about it and almost always reported the pollution of petrol injectors and even in that case, I did not understand never a granch?...to which I would like to take advantage of the expertise of several of you who know how to long to know what c'? to know about it explained in the most understandable way possible....
so what do you say we talk about it??
From the little that I know on this topic the Duty Cycle ? the opening time of the injectors; if, for example, have a DC of 60%, the injector will stay? on the "OFF" for the remaining 40% of what some books call it the "injection timing", or IDC, then, the duty cycle of the single injector on a "IPW Injector Pulse Width" of 100ms will be 60ms. The DC varies according to the quantity? diesel demand; it speaks of the Duty Cycle static when this value ? to 100%! As far as I know this value can? be detected with a simple multimeter, but don't ask me how *_*.
elettro72
07-12-2012, 01:20
with a multimeter I don't think that you can detect,you need an oscilloscope if you want to see the waveform
basically I want to say that the common rail injectors have the DC always at 100%?
In the Common Rail injectors are always open and dumping fuel even when not c'? the request or the time of opening varies according to demand at a given time of injection? I believe that it is pi? correct to say that you reach a DC static, or 100% when the duty cycle of the single injector covers all the all the time of injection.
prejudice in the common rail they are missing anything with the petrol injectors and no one sees no duty cycle because they are controlled in current and work x pressure difference
then remember there are those electromagnetic and those piezoelectric are managed in such a way comlpetamente several
ok but how the f? the injector to inject 1-2mm3 of diesel and then switch to the full extent?? only by "width of the signal" ecu?if the signal varies from so little to so much to inject the right amount? case of diesel, or the maximum flow that this can give in concert with the press the "magnetic coil of the injector is actuated,according to me, for the strength of the duty cycle from minimum to max....but I would not say crap....I look forward to the intervention of giarras and robys on to learn what to say to me...
it is necessary to distinguish the maintenance with the current if you know these two quantities maybe you'd be + convinced and you would have ideas + clear
and, in fact, the current, I do not understand a jot...could you explain to me the key please??
it is not easy to explain so in two words, I do not know if you to a workshop but if there lai I advise you to attend the courses, which are everywhere to start just with the basic ones and where are explained the basics of electrical engineering
I believe that the maintenance,as you say,to open a injector is always 12v, if anything, what changes ? the amperage...now seen that to open the injector 1us it will take e.g. 3 amps to open it to 10us there will be an amperage of 30 amps...between 0 and 3A ? a percentage of the duty cycle between 0 and 30A ? another percentage of the duty cycle.....but very wrong I'm wrong...what in summary I would like to know by opening this tread ?:we put the case that we have on a given engine common rail injector maximum flow rate available open 1050us ori and I'm going to increase the open time using the map to 1300us by increasing the injection time of about 19%, and then I think, also the duty cycle of as much as,if I ori I have the injector that es works 85% of DC after the mod I ritrovero with a DC of 104%!!I believe that if my reasoning ? the exact is not a good idea to work an injector with that DC...
elettro72
07-12-2012, 18:29
hello munro for the duty cycle you are completely out of the way,the duty cycle ? a train of pulses that changes the duration of on and off (they are missing anything amps) but what changes is not ? even the tension ? always the same, but ? the width of the pulse changes i.e. the time in which the square wave is ****llo logic high(maximum voltage) and ****llo logic low(the minimum voltage),if our voltage put is 12 volt we will 12 volt=**** th e maximum and 0 volts=**** llo minimum .......I give you an example if I have a square wave for 5ms remains has ****llo logic high (12volt)and the other 5ms remains ****llo low logic (0 volts) I have a duty cycle of 50%,if I want a duty cycle of 60% avr? 6ms remains has ****llo logic high (12volt) and 4ms remains ****llo low logic (0 volts) and so on.if you measure with a multimeter the duty cyle to 50% do not have 12 volts but the destination i.e. 6 volts if you measure it with an oscilloscope, you'll see the true form and the time in which the pulses are changing ,not s? if I explained it well, however, try your search with ****** you can understand certainly the concept of the duty cycle
not c'? you need to look for with ****** why me lai explained much more understandably you have!! thanks!!! now for? since we have established that the injector common rai lha a duty cycle as we connect this with the reasoning that I was primasulla mod to increase the time, and I think also of the duty cycle??
anyway, guys ? always 12V voltage to the injectors,
many units come to send up to 80V on the car
(on the cover of the tappet Volvo Fh12 if I remember correctly, c? written 90V) !
but volvo montano injector pump which I believe have a different function from the common rail injectors....certain that pr? 90v, and, and a lot of voltage..***** and the hell f? to raise the voltage up at those voltages??
you ? true that mounts to the injector pump but the electric part dell injector limits the time that splash, it's obvious to all 100% duty cycle the injector sends gi? everything from the cams, at least I understood so?! so if you ? just suffice it to increase the time x to get to full extent,.. someone I correga if I told you some nonsense !!
the same argument then you might as well implement listing of resources common rail injectors...what? if these work 100% of DC send down the whole press of the pump provides...and then he was right V. V. to say that not c'? DC....I hope I have not said crap.....
giarras,robys and dr. chem please give me some advice about....
emilground
28-12-2012, 14:20
Common rail injectors working at high voltages ( over 72 volts). With 12 volts you would need a pi? high to make them work. Pi? ? the tension high and the child will be? the required current and thus also the cables can be pi? thin. But the tension also varies the frequency. Some multimeters professional can measure both the duty cycle and the frequency in Hz. Of course with an oscilloscope ? all pi? clear, but let's talk about equipment costs are very different.
hi to all, I can make you the example of the injectors mounted on a scania engines that have passed recently by the pde system (injectors, pump) to the system xpi (commonrail)
in the case of the pde, the control unit sends a constant current and constant energizing the coil when the injector must not inject, and when the controller removes power from the coil loses its magnetism by opening a valve that does fill the chamber of the pump, and then varying the time of the excitement of the coil and the ecu adjusts how much fuel is injected.
the xpi system works in the reverse as regards the electrical part, when the coil ? energized attracts a s? a plate, which through a sphere, opens a passage of diesel fuel (return) that does relieve the pressure in the upper part of the pin, and for a matter of difference of pressure between the top and lower the needle rises and injects the diesel, thanks to this system not linked to the camshaft as the pde we can have both the pre and post injections even as short as it all depends on the time that the control unit sends and removes power to the coils
ok...all very nice but the doubt as to the duty cycle of the injectors remains almost unchanged....
what I was trying to say ? that, from what's? common rail injectors or are open or closed, does not have an intermediate stage or a partial opening, then ? only the control unit which decides the amount? of diesel fuel, according to the times of on/off of the current
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