lds08080808 发表于 2024-8-13 13:46
非常感谢你精彩的解答，再请教下27章节开路电压测试，次级正常是有两组输出，次级两组分别标识为1,2,3,4 ...
27.1章写的很清楚，要考虑次级端子 with or whitout 任意组合的内连接，然后测开路电压。37V是有效值吗？ 你仔细读27.1章节下面的小字哦，标准是说当次级端子互联时候，可以超过42.4Vpk, 没有说超30Vrms. 所以你想用17.4.2来判，应该不行的，建议你问问UL这种情况怎么办，估计要你要5085-2，Class 3类变压器。。。
head0819 发表于 2024-8-14 09:54
27.1章写的很清楚，要考虑次级端子 with or whitout 任意组合的内连接，然后测开路电压。37V是有效值吗？ ...
V1,V2满足有效值30V，峰值42.4V，但互联后，V3，V4就有效值和峰值都超了。（不互联 就V3 V4也不超），看到27后面有一行，就以为是可以豁免这种V3，V4互联超限值情况。
Note: The open circuit voltage between secondary terminals of a two-secondary winding transformer may exceed 42.4 V
peak when secondary terminals are interconnected, if the following conditions are met:
a) The open circuit voltage between any two terminals is not more than 42.4 V peak when no connections
are made between secondary terminals and
b) The transformer is marked in accordance with Clause 17.4.2
17.4.2 A transformer with multiple secondary windings as described in Clause 4.3 having an output
exceeding 30 V rms or 42.4 V peak, or a transformer with an output current exceeding the limit specified
in Clause 28.1.1 or Clause 28.3.1, shall be marked where readily visible after installation, with the word
″WARNING″ and the following or the equivalent: ″Risk of electric shock or fire, do not interconnect
secondary windings.″ The word ″WARNING″ shall be in letters not less than 3.2 mm (0.125 in) high. The
remaining letters shall be not less than 1.6 mm (0.063 in) high.
head0819 发表于 2024-8-13 09:28
问题1：你找一个大一些的整流二极管（越大越好）， 接到次级， 这个二极管就能实现了半波整流， 然后把输 ...
再请教下大老28.1.2a)条件，装PTC过流装置，是否在5S内要记到数，还是5S后记数，是否在5S动作后，没有读数也可以了。
