新進會員
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人o地根本就冇講過要增加電量 ,
係你自己講 增加電量會燒燈
之後就話人唔識o野
呢d 轉移視線o既方法 , 三歲細路就話會俾你mislead .
唔增加電量 , 但係用唔同o既電
一樣可以有不同o既回電時間.
well , 你都made a good point ,
等大家用燈小心 d ,
不過你都係想showoff o者,
點解你個個group 都咁鍾意showoff 呢 ?
咁又係o既, 不嬲串開, 唔死撐又真係幾樣衰. 我都好明白. |
新進會員
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I intend to increase the capacity but not voltage. Still use 4 1.2v cells. before the event, i did not know Nicd cells can have such a low internal reisitance that lead to such a high current. |
新進會員
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As my knowledge,
Depends on V=IR. With a fix voltage condition, if a flash get full charge condition with shorter time, mean current go through the flash components must be larger.
As I know most rechargeable AA batteries on market is 1.2V. That"s mean if you use a rechargeable batteries on your flash will give a shorter charging time result. No exception that current (peak currect) go through the flash components is larger. As mickey_mouse said, it cause by the internal resistance of batteries.
If your flash is made on the old date. And the flash manufacturer never expect there have such a low internal resiatance of betteries on the market. That"s mean it is possible that they use lower rating (than nowadays flash) electric components to made their flash. So... 燒燈 is possible, when you try to achieve short charging time on your flash.
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新進會員
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> photosharp_kai
似乎係你先入為主覺得超人寸 (雖然有時佢又幾係o既)
不過睇番佢果句 "有冇想過, 閃燈回電快, 係好易燒支閃燈?" 真係無乜問題, 唔好咁敏感 |
新進會員
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To:photosharp_kai
多口講句,因為呢個係電池放電時間快慢,
已經係同電流量有直接關係.
所以超人講o既,都係都係有佢道埋.
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新進會員
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Hong Kong people are well trained to answer question "directly" and according to "syllubus". Many people are not comfortable to brain storming or lateral thinking. |
新進會員
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新進會員
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新進會員
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厲害厲害, 估不到小小問題, 都可以去到那麼學術... 已超出小弟可理解...(又或是超出小弟可花時間去理解) 的界限了... |
新進會員
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No need to know those technical things. Just need to know the following quote in the link " http://www.hamuniverse.com/batteries.html""We learned that NiCads and sealed lead acid cells were best for high current applications, while other varieties, such as rechargeable alkaline and nickel metal hydride work well for low current applications." That is, Nicd batteries generally give you shorter recharge time for flashes. Just becareful if the high current harm your flash. I am just afraid that Nicd batteries are fading out. |
新進會員
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我係做電池o既 engineer.
唉. 有時對住d 識少少扮代表o既人真係好無耐. |
新進會員
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I will feel sorry whenever someone has to tell what one is doing in real life to justify oneself. What a pity. |
新進會員
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O下, 做engineer都唔警告用家有潛在危險性? 仲指責指出此問題的網友為浪費資訊.....真係好pro喎!
photosharp_kai, 其實你認為快速回電有冇潛在危險o家? 你咁pro, 不如過ｄ料比大家呀....
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新進會員
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photosharp_kai
如果真係電池o既 engineer
請你告訴我們 NiMh 既 cell diagram
我就不是什麼engineer, 只係個天真既中學生 |
新進會員
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新進會員
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小弟之前有枝540EZ還記得說明書上好似有寫住不可以不停地
用Full Power打發出十多次(唔記得是十 X 次了)
話會易燒支閃燈喎?
還請大家引正! |
新進會員
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Don"t push too much.
I am afraid that, one would give out more qulifications to justify oneself again.
If those battery professionals here write out some bible on battery from the beginning of this threadf or us, it would be more positive toward this discussion rather than comparing qualifications.
I intend to use professionals on the above statement because I believe there should be many engineers or above here. How can you be sure that you have better qualifications than other on Internet?
It is very shameful when you hold the professional knowledge, you do not share it but use it to blame other experiences are wrong. It is the real wasting of the internet resources.
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新進會員
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550EC說明書有這一段：
"為防止閃光燈燈頭過熱和損壞，不要連續進行頻閃10幅以上，進行10幅頻閃攝影後，請讓550EX閃光燈至少冷卻10分鐘。" |
新進會員
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一般外置閃燈設計都有不太差的線路, 但礙於閃燈體積問題, 升壓中的主要零件(MOSFET/SCR)所連接的散熱片而積有限, 而空間天是密封式, 在多次急速充電之下, 其熱量的聚積就 變得極高. 而中古的閃燈設計簡單, 那些AUTO CUT OFF是將 電容器內的電力, 以分配形式輸出至閃管或電阻, 當測光體 發覺閃光足夠是, 電容的其實電量就會流到電阻, 情況是光 亮度是得宜, 但理論上依然是全消秏那次所充的全部電力. 如這類原始設計加上高容量及低內阻電池時, 連續閃光的危 險性十分高! 因此, 很多機頂燈都有獨立的POWER PACK, 部份POWER PACK 不是供應特大容量的低壓用以取代機內的4枝AA, 而是供應高 壓, 即是那個升壓後的電容器電壓(300~350VDC), 目的是將 機內充電線路的負荷減低, 改由可以更大電流設計的升壓分 擔. reference: http://www.star.ucl.ac.uk/~rwesson/esif/om-sif/flashphotogroup/315v_power_pack.htmhttp://www.underdog-battery.com/dogfather.htm |
新進會員
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Oh. Luckily, i seldom 連續閃光 with my poor DIY. Otherwise, situation may be more terrible. |
