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[#21] 隔直流    
#20 硅整流子兩端的壓降非常低,發熱量輕微,並在其上的電解電容,其工作條件和環境,其實非常輕鬆,schmike師兄盡可放心啊。
羅密歐
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202.xxx.xxx.99
2017-04-05 13:41
[#22] 隔直流    
bryston 和另外兩電路都唔同, figure 8 的是串聯在輸入及輸出, bryston 就並聯電容而且兩組電容是正負對調了的,一組正腳輸入負腳輸出, 另一組是負腳輸入, 正腳輸出, 即條link figure 3 的電路, 其實那一個電路才對?

最後修改時間: 2017-04-05 14:25:34
linger
個人訊息 會員
118.xxx.xxx.27
2017-04-05 14:19
[#23] 隔直流    
#22. Fig8的解說文字,已經說明為何作者認為串聯比並聯優勝,這主要是關於長時間應用的可靠性。

Figure 8 shows the final (and recommended) design. While electrolytic caps can withstand a small reverse voltage (around 1V is typical), in the interests of longevity it is probably better to use the caps in series. Being in series, the capacitance of each must be doubled, and as shown the total effective capacitance is 2,350uF. Larger electrolytics can be used if desired, and a medium voltage rating will be required to ensure they can withstand the ripple current (this must be verified! ). Make sure the caps are well clear of anything that gets hot in operation.

While it is probable that using the caps in parallel as shown earlier will work reliably for many years, this is not something I can guarantee, because I've not performed any form of accelerated ageing process to the circuit. Not having used the circuit in any of my own equipment, I have no data either way.

建議linger兄先Google,了解一下bipolar capacitor的構造,理論和短板。還有,這個是AC電路,環路內並沒有你所說的[輸入]和[輸出]觀念,它不是一個擴音機啊。

如果依然有懷疑,建議你按Bryston的電路來造,那可是經過實際量產考證過的。不過,如果你還是參透不明箇中道理,還是不要造好了,需知市電是會致命的!

最後修改時間: 2017-04-05 16:35:33
羅密歐
個人訊息 會員
219.xxx.xxx.216
2017-04-05 16:32
[#24] 隔直流    
Thanks 羅兄, 多謝你的資料.

輸入輸出, 我是用來描述那裡接來電的火線(輸入) , 那裡接火牛(輸出). 不是擴音機的輸入及輸出, 係我表達得不太清楚. ^-^
linger
個人訊息 會員
118.xxx.xxx.27
2017-04-05 18:36
[#25] 隔直流    
#1 圖我用左好耐,如果佢有問題,地球上已經由我做成超過1000單意外了。
simon62
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106.xxx.xxx.88
2017-04-05 20:22
[#26] 隔直流    
鬼佬發明另一種電路

simon62
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106.xxx.xxx.88
2017-04-05 20:25
[#27] 隔直流    
搵下又多一幅

simon62
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106.xxx.xxx.88
2017-04-05 20:27
[#28] 隔直流    
#21
實際測過了
知道是沒問題
只是不喜歡電解
哈哈
schmike
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58.xxx.xxx.163
2017-04-05 20:34
[#29] 隔直流    
原來係低仿Rubycon,係九龍電子買.咁大家要小心!

羅密歐兄解釋得好清楚.贊!

有啲師兄真係好笑!又過引!

幾年前買咗隻三千火隔離牛係圓牛,一插電起震!攞番代理試同老友到試都冇問題!
因住村,電壓都有啲唔穩定仲加埋有直流,
係網上搵到成因同解決方法,線路圖.
冇人幫手做又唔係好識電子嘢為有膽粗粗,
跟圖做咗個隔直流.隻隔離牛靜哂.用咗幾年到宜家都冇事



foxhung
個人訊息 會員
116.xxx.xxx.158
2017-04-05 20:36
[#30] 隔直流    
schmike兄
我唔係好識電子嘢.
你幫我答咗好多問題唔該哂.
foxhung
個人訊息 會員
116.xxx.xxx.158
2017-04-05 20:42
[#31] 隔直流    
#27 的圖就是以下條link figure 8 的電路.

http://sound.whsites.net/articles/xfmr-dc.htm
linger
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222.xxx.xxx.122
2017-04-05 21:28
[#32] 隔直流    
figure 8 電路圖的電容, 可否改用10UF?

如果得, 唔用電解, 改用MKP, 會不會更好效果?
linger
個人訊息 會員
222.xxx.xxx.122
2017-04-05 21:32
[#33] 隔直流    
#32 不可以,電容量大小了。

Voltage Drop - Now that we have the current, we can work out the required capacitance. Keeping the RMS voltage across the capacitor below 1V would seem like a reasonable figure, and I'd suggest that the maximum current of interest is around ¼ of the full load current - about 500mA. This means that capacitive reactance must be 2 Ohms or less. Remember that we can use Ohm's law to make these calculations - at least up to this point. Calculating the capacitance needed means that we use the capacitive reactance formula, suitably rearranged ...

C = 1 / ( 2 * π * f * Xc ) where f is frequency and Xc is capacitive reactance
C = 1 / ( 2 * π * 50 * 2 ) = 1,590uF
That's a fairly large capacitance, and can only be economically realised using an electrolytic capacitor. This raises a new quandary - electrolytic caps can operate for many years without a polarising voltage, but only at very low voltages. This means that the maximum voltage across the cap(s) must be limited, or they will fail. To be sensible, it will be necessary to use a pair of electrolytic capacitors, wired in "anti-parallel". A normal series connection with the two negative (or positive) terminals joined will also work, but reduces the available capacitance and maximises ripple current through both caps. Nonetheless, this may be preferable (see conclusion). The traditional way to limit the voltage is to use a number of high current diodes in parallel with the caps.
羅密歐
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219.xxx.xxx.216
2017-04-05 21:49
[#34] 隔直流    
改用MKP是可以的,不過千多二千µ的薄膜電容,體積要有多大!
羅密歐
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219.xxx.xxx.216
2017-04-05 21:52
[#35] 隔直流    
諗起用MKP嚇死人
schmike
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58.xxx.xxx.163
2017-04-05 22:26
[#36] 隔直流    
只用係音響!

foxhung
個人訊息 會員
116.xxx.xxx.158
2017-04-05 23:23
[#37] 隔直流    
供參考。


http://www.emsd.gov.hk/m/tc/electricity_safety/periodic_test_for_fixed_electrical_installations/frequently_asked_questions/
羅密歐
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219.xxx.xxx.216
2017-04-05 23:42
[#38] 隔直流    
我諗呢件野放係部機到會好d
schmike
個人訊息 會員
58.xxx.xxx.163
2017-04-06 00:08
[#39] 隔直流    
唔好跟咁做!
係15A蘚輸出在加會好啲.





foxhung
個人訊息 會員
116.xxx.xxx.158
2017-04-06 01:10
[#40] 隔直流    
我就做咗個13A插座箱用.



最後修改時間: 2017-04-06 01:56:44
foxhung
個人訊息 會員
116.xxx.xxx.158
2017-04-06 01:55
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