同步多火花模块(SMSM)的电子点火装置(Eid)
同步多火花模块(smsm)的电子点火装置(eid)
multi-spark ignition is very useful especially in the case of startings at low temperature and at low rpm range. basic idea, is to apply to spark plugs instead of only one spark, a “spark-burst” having big energy. in this case, combustion of air/fuel mixture is much better and the emissions are more reduced. in addition, through burning improvement, the consumption of fuel can be reduced.
why synchronized multi-spark, or what means this?
special literature abounds in multi-spark eid schematics. these have in common the fact, as the breaker-points don’t control directly eid, but an oscillator, which will generate a succession of impulses, and these impulses shall command eid. this aproach has two major deficiencies:
1. first spark doesn’t match exactly with the moment of breaking points; so, it has an aleatory delay toward this. this is equivalent to an aleatory modification of ignition advance, which will leads to non-uniform run of engine.
2. at high rpm range, the time between two impulses of multi-spark device can become comparable with the time between breaker-points impulses; this shall lead to an unstable operation of engine, with trepidations and knockings. to avoid this trouble, is necessary to switch-off the multi-spark device when rpm of engine exceeds a certain value.
with these in mind, i imagined the device described forwards.
few calculations elements
the crankshaft velocity of an internal combustion engine is given by following formula:
where :
n = revolution speed of engine crankshaft (rpm)
m = strokes number (2 or 4)
n = number of sparks per second (sparks frequency, in hz)
b = number of ignition coils
c = cylinder number
for usual four stroke engines, with 4 cylinders and a single ignition coil, the formula becomes :
from where :
in fig.1 is shown an eid equipped with synchronized multi-spark module.
shaping block has the role to provide fixed length impulses (2 ms) at each breaker-points opening. in this way are eliminated the false impulses which appear due contacts vibrations.
as shown in drawing, shaped impulse triggers directly the eid and act as start impulse for multi-spark module. if rpm of engine is under speed limit, the module will generate a series of supplementary impulses that, through an or gate, will generate supplementary sparks by eid. when speed limit is reached (for example, 2000 rpm), supplementary impulses stops at module output, thus no supplementary sparks will be generated.
functional description
the module uses for control the shaped impulses from breaker points. the time between two consecutively impulses depends on rpm engine and has the values shown in upper table.
from whole t interval, only in the first half of this will be generated supplementary sparks, after the main spark produced by the breaker points. this is very important, because generating sparks outside of half of the interval, the spinning distributor could apply these sparks to next cylinder, and this could be very harmful for mechanical parts of engine.
in fig. 3 is shown the block-diagram of the multi-spark module.
at breaker-points opening, the shaping circuit (not shown in drawing) produces a square impulse having 2 ms. this, named bp, is applied to eid by an or gate and generate the main spark.
in multi-spark module, during 2 ms interval, a sequence timer (a counter with decoded outputs) accomplishes the initialization of circuits (full operations will be detailed later). when impulse bp disappears, the gate p2 is opened and the counter n1 receives impulses with 1 ms period, from clock generator. this 8 bits counter measures, in fact, the duration between two breaker-points impulses. it can count maximum 255 impulses, each having 1 ms (see the table, this correspond to 120 rpm, far below the free running speed !). at next bp impulse, p2 close and the counting stop. the number stored inside n1 is in fact the time length between two bp impulses.
the sequence timer “copy” the number stored in n1 to n2, after this resets counter n1. when bp becomes low level, n1 restarts the counting. in the same time, the up/down counter n2, starts counting the impulses having 0.5 ms period, which comes via gate p1. it counts down, but with double speed. in this way the counter n2 reach to “0” after t/2 time. the counter n4 and gate p5 makes the impulses for supplementary sparks (2 ms length).
this counter works only if inh signal is at low level. the fip-flop ff1 “marks” the interval t/2 in which will be generated supplementary sparks. it is reseted when n2 reach “0”. the gates p3 and p4 unlock the flio-flop and start supplementary sparks. also, these gates switch-off the multi-spark function when engine speed limit is reached (in this case, ~ 2000 rpm). how works this ? in the upper table we can see at about 2000 rpm, the time length between two bp impulses is 15 ms.
this means as after a counting cycle, the first 4 bits of counter n1 will be 111 and next 4, 0000. in this case, p3 gate output will be at low level, and the same value for p4 output. the flip-flop ff1 will be not set, and as result, no supplementary sparks. if the speed engine decrease (time length t increase), the last 4 bits of n1 will have at least one 1 and the flip-flop will be set. this allow to appear supplementary sparks until flip-flop will be reseted by borrow impulse of n2.
the module can be maked like a plug-in adapter for an eid.
指纹识别介绍
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multi-spark ignition is very useful especially in the case of startings at low temperature and at low rpm range. basic idea, is to apply to spark plugs instead of only one spark, a “spark-burst” having big energy. in this case, combustion of air/fuel mixture is much better and the emissions are more reduced. in addition, through burning improvement, the consumption of fuel can be reduced.
why synchronized multi-spark, or what means this?
special literature abounds in multi-spark eid schematics. these have in common the fact, as the breaker-points don’t control directly eid, but an oscillator, which will generate a succession of impulses, and these impulses shall command eid. this aproach has two major deficiencies:
1. first spark doesn’t match exactly with the moment of breaking points; so, it has an aleatory delay toward this. this is equivalent to an aleatory modification of ignition advance, which will leads to non-uniform run of engine.
2. at high rpm range, the time between two impulses of multi-spark device can become comparable with the time between breaker-points impulses; this shall lead to an unstable operation of engine, with trepidations and knockings. to avoid this trouble, is necessary to switch-off the multi-spark device when rpm of engine exceeds a certain value.
with these in mind, i imagined the device described forwards.
few calculations elements
the crankshaft velocity of an internal combustion engine is given by following formula:
where :
n = revolution speed of engine crankshaft (rpm)
m = strokes number (2 or 4)
n = number of sparks per second (sparks frequency, in hz)
b = number of ignition coils
c = cylinder number
for usual four stroke engines, with 4 cylinders and a single ignition coil, the formula becomes :
from where :
in fig.1 is shown an eid equipped with synchronized multi-spark module.
shaping block has the role to provide fixed length impulses (2 ms) at each breaker-points opening. in this way are eliminated the false impulses which appear due contacts vibrations.
as shown in drawing, shaped impulse triggers directly the eid and act as start impulse for multi-spark module. if rpm of engine is under speed limit, the module will generate a series of supplementary impulses that, through an or gate, will generate supplementary sparks by eid. when speed limit is reached (for example, 2000 rpm), supplementary impulses stops at module output, thus no supplementary sparks will be generated.
functional description
the module uses for control the shaped impulses from breaker points. the time between two consecutively impulses depends on rpm engine and has the values shown in upper table.
from whole t interval, only in the first half of this will be generated supplementary sparks, after the main spark produced by the breaker points. this is very important, because generating sparks outside of half of the interval, the spinning distributor could apply these sparks to next cylinder, and this could be very harmful for mechanical parts of engine.
in fig. 3 is shown the block-diagram of the multi-spark module.
at breaker-points opening, the shaping circuit (not shown in drawing) produces a square impulse having 2 ms. this, named bp, is applied to eid by an or gate and generate the main spark.
in multi-spark module, during 2 ms interval, a sequence timer (a counter with decoded outputs) accomplishes the initialization of circuits (full operations will be detailed later). when impulse bp disappears, the gate p2 is opened and the counter n1 receives impulses with 1 ms period, from clock generator. this 8 bits counter measures, in fact, the duration between two breaker-points impulses. it can count maximum 255 impulses, each having 1 ms (see the table, this correspond to 120 rpm, far below the free running speed !). at next bp impulse, p2 close and the counting stop. the number stored inside n1 is in fact the time length between two bp impulses.
the sequence timer “copy” the number stored in n1 to n2, after this resets counter n1. when bp becomes low level, n1 restarts the counting. in the same time, the up/down counter n2, starts counting the impulses having 0.5 ms period, which comes via gate p1. it counts down, but with double speed. in this way the counter n2 reach to “0” after t/2 time. the counter n4 and gate p5 makes the impulses for supplementary sparks (2 ms length).
this counter works only if inh signal is at low level. the fip-flop ff1 “marks” the interval t/2 in which will be generated supplementary sparks. it is reseted when n2 reach “0”. the gates p3 and p4 unlock the flio-flop and start supplementary sparks. also, these gates switch-off the multi-spark function when engine speed limit is reached (in this case, ~ 2000 rpm). how works this ? in the upper table we can see at about 2000 rpm, the time length between two bp impulses is 15 ms.
this means as after a counting cycle, the first 4 bits of counter n1 will be 111 and next 4, 0000. in this case, p3 gate output will be at low level, and the same value for p4 output. the flip-flop ff1 will be not set, and as result, no supplementary sparks. if the speed engine decrease (time length t increase), the last 4 bits of n1 will have at least one 1 and the flip-flop will be set. this allow to appear supplementary sparks until flip-flop will be reseted by borrow impulse of n2.
the module can be maked like a plug-in adapter for an eid.
指纹识别介绍
注射针韧性测试仪是提高注射器质量与安全性的关键工具
MintBox 3系列迷你主机上架，搭载双千兆以太网端口
LabVIEW实时控制器担任着中央系统控制器的角色？
ROS软件平台对服务机器人的运算与控制
同步多火花模块(SMSM)的电子点火装置(Eid)
火炬气超声波流量计用于硫磺回收装置酸性气的流量测量
Linux bash中的printf命令详解
阻抗板的要素分别是什么
到底是什么导致：摩托罗拉无限期推迟智能手表项目
常见风速传感器的原理及应用领域
达尔优EM910 Pro釉下青双模游戏鼠标即将到来
基于无人机成像高光谱估算马铃薯植株氮含量-莱森光学
pcb设计中，PCB中图层的显示和布局同样重要
微软推出了一个“Mcabook到Surface Book”网站，让你随意跳转
皮肤杀手紫外线UVA波段领域中的传感器
“量子自旋磁力仪”亮相2023世界制造业大会
MAX8660/MAX8661电源管理IC (PMIC)
苹果计划推进电动汽车生产计划 股价最新上涨2.9%
全球多家央行正在探索和使用区块链项目