Short click, long click, Continuous, Combination of clicks这四个名词相信做过EMC的童鞋们都不陌生,但对于其的区别和相关定义标准上没有一个明确的界定,争议也比较多,所以在这里想和大家讨论一下个人的看法,也想听听大家的意见:
首先看一下Click的定义:
3.2 click
a disturbance, the amplitude of which exceeds the quasi-peak limit of continuous disturbance,the duration of which is not longer than 200 ms and which is separated from a subsequent disturbance by at least 200 ms. The durations are determined from the signal which exceeds the i.f. reference level of the measuring receiver
按照标准Click的判定流程:所有Click<20ms,90%<10ms且N<5就可以直接判PASS,否的话就要进行下面的流程,run第二次,在这里是否可以推算出short click<20ms?? 而根据Click的定义是否可以有
20ms<long click≤200ms??
continuous>200ms??
再来看看Combination of clicks
4.2.3.2 Combination of clicks in a time frame less than 600 ms
In programme controlled appliances a combination of clicks in a time frame less than 600 ms is allowed once per selected programme cycle. For other appliances such a combination of clicks is allowed once during the minimum observation time. This is also valid for thermostatically controlled three-phase switches,causing three disturbances sequentially in each of the three phases and the neutral. Thecombination of clicks is considered as one click.
figure 4 Examples of discontinuous disturbance for which the limits of continuous disturbance apply (see 4.2.2.1).
For some exceptions from this rule see 4.2.3.2 and 4.2.3.4.
click是一种干扰,定义中明确规定这种干扰的时间特性,但是600ms的这个情况首先并不满足click的定义,其次,这种干扰比较常见(可能是电冰箱中比较多,或者程序控制选择开关动作时产生的干扰),这种情况就定义为Combination of clicks in a time frame less than 600 ms,
但是标准明确提出a combination of clicks in a time frame less than 600 ms is allowed once per selected programme cycle. 请注意once这个单词,就是说在一个程序循环中,只允许发生一次,所以从能量的角度来理解,这种干扰可以默许,因为他的能量比较小,并没有足够的能量对外界产生干扰。