水草情迷

Overdrive (或者 underdrive) HQI 係有機會爆膽燒牛！

Macbrush兄, 恕我問多句，你所說的 『Overdrive (或者 underdrive) HQI 係有機會爆膽燒牛！』係唔係你(包括草友)有咁既經驗呢？我的見解只係從一般常識去"估", 好似買電腦佩火牛，通常都會佩隻watt數大D既，依你的見解, 如果佩隻岩岩好既，日後要加插附件落底板便會overdrive，亦會燒牛，還是，HQI (或燈) 的牛唔同，總之要70W牛佩70W燈，150W牛便一定要佩150W燈，不能多，不能少，謝謝！

我就有少少唔同意你的講法．首先，"爆"係爆支燈，而唔係爆(燒)隻牛．你所講的電流係Input電流，而"爆"燈講的是Output電流．

我之前都計過:


咁你話用咗150W牛後個Current由1A去到1.8A，支燈會唔有"爆"的危險呀．我覺得我支燈頂得往都係個品質好而已．

cpkd 兄，有趣，大家研究一下:
你話隻牛
Output Current 是1.8A 及 1A (我不討論你的計算方法)
其實係佢『有能力』output 最多1.8A 及 1A, 多過1.8A 或 1 A, 佢自己就因為current 過大而燒， 支燈既內阻是固定的，只要隻牛個output voltage 不變，係唔能夠由你所講既"1A"谷到"1.8A"的，換句話說，要谷入"1.8A"就要加大output voltage，所以我認為爆燈情況應該係隻火牛output voltage 唔穩定(支燈老化內阻減低另作考慮)，所以名廠燈貴D其中一個原因係因為隻牛有能力穩定地輸出電壓，試試比較電腦的火牛，點解價錢爭甘遠，就是這個原因。
希望我講岩，因為想diy hqi 的網友可以買隻150 Watt 既牛，佩70 watt 既燈，遲D upgrade 支燈去150watt 都唔駛換牛啦。甘，係唔係買隻1500 watt 牛唔係一定安全？(我的)理論上，係，但是，當1500 watt (或150 watt) 牛帶 70 watt 燈，會有 loss，等於10000 cc 引擎裝落架私家車，這又是另一個考慮了。

"HQI 70W 膽，如用150W電子牛"......100% no problem.....

聽完Fans的講法後．不瞞你說，我真的有種似是而非的感覺．正當我一邊想是否將所有讀書所學，忘記得一干二淨；一方面在努力找書之際．突然我靈光一閃，看出問題的所在．

首先，Fans兄所講的的確冇錯；但其所講是建基於"隻牛個output voltage 不變"的講法之下才會成立，而150W與70W膽所用的Voltage卻有所不同．雖然我在Osram的網頁找不到150W與70W膽所需要的實際Voltage，不過卻有其所需的Amp數（150W:1.8A ; 70W:1A）．所以，根據以上的資料．我可以計算出150W與70W膽所需的Voltage為83.33V與70V（V=P/I)，內阻為46.29與70（R=V/I）．而我們一般所買的HQI專用變壓器（火牛）卻不能調教其輸出Voltage．故此，如硬將150W膽的變壓器（火牛）用在70W膽上．因輸入的Voltage由70V升至83.33V，70W膽的輸入的Amp數將由１A升到1.19A．而原本70W輸出的膽也會升至99.16W．

其實，只要膽的品質不錯的話．我相信0.19A及13.33V的提升是沒有什麼大的問題，而且仲可以多得到差不多30W的光度，的確吸引．不過長此下去的話，枝膽的壽命就如電腦玩超頻一樣，好快玩完．再者，如變壓器（火牛）的輸出有所不穩，"爆"的機會就會相應提高．所以安全計都係花百幾銀買隻適合的變壓器（火牛）罷了．

"70W膽的輸入的Amp數將由１A升到1.19A．而原本70W輸出的膽也會升至99.16W",
對, 只不過支燈正在"超頻", 支燈 factory rating is 1A means maximum current input for safe and optimum usage is 1 A.
Just for learning, the lamp itself is a "resistance", only that the manufacturer didn't cover up it is capable to output 70 W power in rated current 1 A, input voltages from 0 V to 70 V, in my own view, is no problem.
Thank you for your sharings!

各位大大，有些少HID燈的問題，小弟做下多口仔。

150W的HID火牛是不能用70W的燈膽！

因為HID火牛是特別為每個火數的燈膽提供:-

1...撻火(起動電弧)的高壓。
2...引起電弧後提供穩定的低壓電流。

希望解答到一些疑問。

Sorry, just want to give my opinion.

In electricity supply, normal the voltage V is fixed. e.g. in computer we normally have 5V and 12V DC supply, HK uses 220V AC etc. The power W indicates the maximum current supported at nominal voltage. So for 70W 燈膽, using 150W 火牛 is OK, but you should not use say 200W 燈膽 or the current will be to high and burn the 火牛.

燈膽 will blow if the input voltage is higher than the nominal voltage. E.g. if you plug a 110V TV in Hong Kong (220V) socket, then the TV will "blow up".

_________________
24' x 12" x 14" Tank. ADA African soil.
2 x 24W T5HO tubes. Turn on 3PM - 7PM & 8PM - 12AM. 1 CO2 bubble per second sync with T5HO

I have experiece HQI explosion, and it was no joke though the reason was not due to incorrect voltage. EVERY HQI manufacturer have warnings for do not overdrive or underdrive HQI bulbs in danger of explosion , in fact, these warnings apply to all pressure lamps. Do you see such warnings on FL tubes, or PL tubes? Personally, I would take these kind of warnings seriously. Everyday so many people mistreat things such as gas cookers, or gas water boilers, I don't see accidents on news everyday, in fact these kind of accident is RARE, but when it happens, every case is serious! And I think we are on the same boat here.

Please don't just say "that's what I am doing, and I am not dead yet" to convince others what might be a hazardous thing to do is safe, simply because you are lucky doesn't mean it is safe! It is so irresponsible!

kvhui:-
You are right！But....撘錯線。
We are talking about HID / HQI Lamp.

Kvhui:你講的，確是晶結所在．我之前講過：

所以150W變壓器（火牛）的輸出為83.33V；70W變壓器（火牛）的輸出為70V．兩種輸出都不同，危險與否，就真是見仁見智了．正如前文所說：

各位是否願意一試，就自己衡量一下吧．