LPS 就是limited power supply,中文就是有功率限制的電源.

參考IEC60950 clause 2.5, 有詳細的定義和要求

測試分為正常條件下測試和單一故障條件下測試兩種,都要滿足.

我手頭沒有IEC60950的標準,麻煩在上面幫我解釋下,感激不盡

暈,有好幾百字呢,沒時間寫呀...

論壇有IEC60950的下載,你找找到,,,

算了,我還是上傳一個吧,,,希望沒人來找我麻煩...

IEC60950-1-2001:1157933870.pdf

請參考2.5條...

謝謝了,文件無法打開呀

不清楚是什么原因,

我也打不開哦...

呵呵,再傳一次吧

不傳了,費時間,上傳要好久...

你找找看,應(yīng)該找得到的...

簡言之 :

對需判定 LPS 的輸出部份 :

一. 量測開路電壓 Uoc. 再加電阻負載, 量測其最大可輸出電流. Isc

二, 進行單一故障/元件失效條件下的 Uoc, Isc.

三, 依 Table 2B, 2C 判定是否符合要求.




2.5 LPS : 在 IEC 60950-1 中 :

對認定 LPS 需應(yīng)符合以下之一:

1. 內(nèi)在使用時需符合 TABLE 2B (V <= 20 時, 輸出電流小於 8 A, 視在功率(S) 小於 5 X Uoc (開路電壓). -- 這是最常的.

2. 使用限制元件以符合 TABLE 2B 要求時, 如果是 PTC 需符合相關(guān)元器件要求.

3. 若使用過電流保護器 (FUSE, NFB... ) 需符合 TABLE 2C (輸出電流 <= 1000 / Uoc , 視在功率 S <= 250 W. V <= 20 時, 保護裝置應(yīng)為 <= 5A.

4. 若使用調(diào)節(jié)限制器(regulating network limit) 需符合 TABLE 2B.
5. 若使用調(diào)節(jié)限制器(regulating network limit)且使用過電流保護器 (FUSE, Breaker) 需符合 TABLE 2C


原文如下 : (表格有點亂了).
2.5 Limited power sources
A limited power source shall comply with one of the following:
– the output is inherently limited in compliance with table 2B; or
– an impedance limits the output in compliance with table 2B. If a positive temperature
coefficient device is used, it shall pass the tests specified in IEC 60730-1, clauses 15, 17,
J15 and J17; or
– an overcurrent protective device is used and the output is limited in compliance with
table 2C; or
– a regulating network limits the output in compliance with table 2B, both under normal
operating conditions and after any single fault (see 1.4.14) in the regulating network (open
circuit or short circuit); or
– a regulating network limits the output in compliance with table 2B under normal operating
conditions, and an overcurrent protective device limits the output in compliance with
table 2C after any single fault (see 1.4.14) in the regulating network (open circuit or short
circuit).
Where an overcurrent protective device is used, it shall be a fuse or a non-adjustable, nonautoreset,
electromechanical device.
A limited power source operated from an AC MAINS SUPPLY, or a battery-operated limited power
source that is recharged from an AC MAINS SUPPLY while supplying the load, shall incorporate
an isolating transformer.
Compliance is checked by inspection and measurement and, where appropriate, by
examination of the manufacturer’s data for batteries. Batteries shall be fully charged when
conducting the measurements for Uoc and Isc according to tables 2B and 2C.

The load referenced in items 2) and 3) of tables 2B and 2C is adjusted to develop maximum
current and power transfer respectively. Single faults in a regulating network are applied
under these maximum current and power conditions.


Table 2B – Limits for inherently limited power sources
Output voltage1)
(Uoc)
Output current2)
(Isc)
Apparent power3)
(S)
V a.c. V d.c. A VA
≤20 ≤20 ≤8,0 ≤5 × Uoc
20 < Uoc ≤ 30 20 < Uoc ≤ 30 ≤8,0 ≤100
– 30 < Uoc ≤ 60 ≤150/Uoc ≤100
1) Uoc: Output voltage measured in accordance with 1.4.5 with all load circuits disconnected. Voltages are
for substantially sinusoidal a.c. and ripple free d.c. For non-sinusoidal a.c. and d.c. with ripple greater
than 10 % of the peak, the peak voltage shall not exceed 42,4 V.
2) Isc: Maximum output current with any non-capacitive load, including a short circuit, measured 60 s after
application of the load.
3) S (VA): Maximum output VA with any non-capacitive load measured 60 s after application of the load.


Table 2C – Limits for power sources not inherently limited
(overcurrent protective device required)
Output voltage1)
(Uoc)
Output
current2)
(Isc)
Apparent
power3)
(S)
Current rating of
overcurrent
protective device4)
V a.c. V d.c. A VA A
≤20 ≤20 ≤5,0
20 < Uoc ≤ 30 20 < Uoc ≤ 30 ≤1 000/Uoc ≤250 ≤100/Uoc
– 30 < Uoc ≤ 60 ≤100/Uoc
1) Uoc: Output voltage measured in accordance with 1.4.5 with all load circuits disconnected. Voltages are
for substantially sinusoidal a.c. and ripple free d.c. For non-sinusoidal a.c. and for d.c. with ripple
greater than 10 % of the peak, the peak voltage shall not exceed 42,4 V.
2) Isc: Maximum output current with any non-capacitive load, including a short circuit, measured 60 s after
application of the load. Current limiting impedances in the equipment remain in the circuit during
measurement, but overcurrent protective devices are bypassed.
3) S (VA): Maximum output VA with any non-capacitive load measured 60 s after application of the load.
Current limiting impedances in equipment remain in the circuit during measurement, but overcurrent
protective devices are bypassed.
NOTE The reason for making measurements with overcurrent protective devices bypassed is to
determine the amount of energy that is available to cause possible overheating during the operating
time of the overcurrent protective devices.
4) The current ratings of overcurrent protective devices are based on fuses and circuit breakers that break the circuit within 120 s with a current equal to 210 % of the current rating specified in the table.

以上.

了解,謝謝,請問你是搞安規(guī)這一塊的嗎?

很多年沒搞了..

這里面的電壓和電流都是指瞬時值嗎﹖

不是瞬間值.

依表中的 :

Uoc : 開路電壓, 不加任何負載下的電壓值.

Isc : 短路電流, 加載 60s 後的最大輸出電流.

1) Uoc: Output voltage measured in accordance with 1.4.5 with all load circuits disconnected. Voltages are
for substantially sinusoidal a.c. and ripple free d.c. For non-sinusoidal a.c. and for d.c. with ripple
greater than 10 % of the peak, the peak voltage shall not exceed 42,4 V.
2) Isc: Maximum output current with any non-capacitive load, including a short circuit, measured 60 s after
application of the load. Current limiting impedances in the equipment remain in the circuit during
measurement, but overcurrent protective devices are bypassed.

我記得在輸出電壓小于20V時還有一個條件﹐是輸出的VA數(shù)小于5*Uoc﹐那么這里的VA數(shù)該怎么測量﹖

另外﹐短路時輸出的電流會是跳變的﹐這個時候我取最大的瞬時值嗎﹖

搞安規(guī)一定是要學電子的嗎,學機械的可以搞的好嗎?小弟是學機械的,現(xiàn)在在搞燈具的安規(guī)認證,覺的壓力好大哦?不知大蝦們能給小弟提一點寶貴的意見嗎?我的郵箱是yangpeteryang@126.com

沒錯.... 那個表格, 貼進來時亂掉了.

Uoc = 開路電壓.

VAmax 小於 5 * Uoc = 五倍 開路電壓值.

你的問題有兩種可能 : 以前的教材呢.. 又找不到了.. .

一, 你在量測 Isc 時, 短路輸出後電源供應(yīng)器就嘗試進入 Shutdown 但無法有效中些, 反覆進行重啟所致. 所以輸出電流會變動. (這種量測是不正確的).

二, 是對 Isc "最大短路電流" 解讀偏差, Isc "最大短路電流" 不一定是直接將 "輸出端點" 短路時的電流.

1. 將設(shè)備輸出端點在直接短路下, 仍可有恆定電流輸出, 那 Isc 即為短路電流.

2. 用 "可變電阻" 接在輸出端點上. 再慢慢加載(減少電阻值, 電流上升)... 到最大輸出電流的可工作點. 此時電流值為 Isc.

3. 所以會有加載 60s 後. 故至少該電流值至少需可正常工作 60s .  (此項或許會有不同解讀, 但是至少有個標準依循).

為何會有不同狀況, 此與電源供應(yīng)器的工作模式及輸出功率, 輸出測試點與全部功率輸出比值, 保護模式設(shè)定... 等都有關(guān).

學機械, 沒關(guān)係啦.

當年學做安規(guī), 還不是只用 "歐姆定律 V = IR", 伏安 = P = VA  用直流電觀念過日子.

像這個 LPS 的問題, 其實只用 "電阻 R" 串接, 再量測電壓 (V), 電流 (I), 算算功率值, 就 OK 了.

看看過往申請記錄, 查查舊檔案卷宗. 上手應(yīng)該很快.

燈具方面, 我經(jīng)驗很少. 恐怕幫不上忙.

呵呵,今天試了一下,可以下載了.

樓上說得極是.安規(guī)只要初中物理,加上識幾個英文單詞就可以了.

各位大俠,安規(guī)這么好做,我也想搞哦,謝謝MIKESU兄這么熱情的講解

各位大哥：

  那做單一失效的情況下，應(yīng)該符合什么要求？