DSH 288/289（IEC 60065）半导体器件区分/音频放大器故障条件
DSH 288
Subject: Semiconductor Devices
Question:
Does the wording "Semiconductor Devices" include:
a) integrated circuits
and
b) hybrid circuits consisting of discrete components mounted to a printed circuit board and encapsulated in a module ?
Decision:
Yes.
Both examples mentioned are considered to be "Semiconductor Devices " in the sense of the mentioned Clause.
问题：
“半导体器件”是否包括了：
a）集成电路和b）分立器件安装在印制板上且封装在模块中的混合电路？
决定：
两种电路都认为属于“半导体器件”范畴。
************************************
DSH 289
Subject: Fault conditions on audio amplifiers
Question:
When applying fault conditions to an audio amplifier (scl. 4.3.9) to determine heating under fault conditions there are two possibilities to do this.
1. Adjusting the apparatus to deliver one-eighth of the non- clipped output power to the minimum rated load impedance [ 8 Ohms) and then changing the load to 4 Ohms without changing the adjustment.
2. Changing the load impedance to 4 Ohms, measuring the non-clipped output power into 4 Ohms, and then adjusting the output to one-eighth of the non-clipped output power.
Which possibility is to be used?
Decision:
Possibility 1 has to be used.
问题：
对音频放大器施加单一故障时，可能有2种方法能确认故障状态下的发热。
1、将1/8非削波输出功率施加在最小额定阻抗（8Ω）上，然后再将阻抗换成4Ω，不做其他调整。
2、将阻抗换成4Ω，测量最大非削波输出功率，再调整为1/8非削波输出功率。
应该用哪种方法？
决定：
方法1。
提示：
DSH 289决议时间有点早，可能很多朋友不清楚为什么是8Ω变成4Ω。由于喇叭阻抗规格基本是16Ω、8Ω、4Ω定值，如果额定阻抗是8Ω，故障试验时要连接不利负载，即连接更小阻抗负载，因此可以选择4Ω，当然也可以选择短路。
决议的重点是，先在额定阻抗上调整1/8非削波输出功率，确认放大器的工作状态，然后再连接不利负载，才能保证试验复现性。
关于1/8非削波相关内容见以下链接：
点击下方名片，关注“朱大侠的质检江湖”微信公众号，一起来研究安规吧
~