johnnykut 發表於 2016-5-13 13:31 static/image/common/back.gif
諗諗下整低電源線既時候，部lps 4個輸出都係12c,,但發覺原來我有時候係需要用到5v
冇理由因為“可能用到” ...
是但用一塊電源板加開關制在機面，打上出12v，打下出5v，for測試用短時間。
穩壓電源板只需改粒電阻數值就可以輸出5v。
本帖最後由 billymud 於 2016-5-14 07:10 編輯
johnnykut 發表於 2016-5-13 13:31 static/image/common/back.gif
諗諗下整低電源線既時候，部lps 4個輸出都係12c,,但發覺原來我有時候係需要用到5v
冇理由因為“可能用到” ...
adding a separate module with low ripple +5v requlator (ie. 12v input, 5v output) isa better option.
billymud 發表於 2016-5-14 03:05 static/image/common/back.gif
adding a separate module with low ripple +5v requlator (ie. 12v input, 5v output) isa better opt ...
多謝billy兄回覆
你既提議我都有諗過，用窿窿板搭個線路，入落隻盒仔，，一來唔駛拆開部lps改入面
二來諗落成塊pcb線路走法，加粒刀制飛線唔知會唔會有影響
所以尋日都有睇下呢方面資料，，見到內地討論區有人提過要做降壓既話，降兩級會比降一級好(12v＞9v>5v)
Billy兄有有建議呢？？？
本帖最後由 billymud 於 2016-5-14 07:48 編輯
johnnykut 發表於 2016-5-14 07:22 static/image/common/back.gif
多謝billy兄回覆
你既提議我都有諗過，用窿窿板搭個線路，入落隻盒仔，，一來唔駛拆開部lps改入面
二來諗 ...
1. 唔駛拆開部lps改入面塊pcb, just buy another +5V requlated module and replace LDO requlator at your wish.
2. 飛線 for what purpose ?if 飛線 just to provide +12 to the +5v req module, that's fine.
3. 降兩級 (12v > 9v > 5v) 會 make the Linear Requlators operating in less heat dissipation.As u're likely to mount the 5V Linear Requlator onto the large metal chasis, it's fine to just run 12v > 5v.
However, if u plan to output 5v 3A, the Req will be pretty hot !!
billymud 發表於 2016-5-14 03:05 static/image/common/back.gif
adding a separate module with low ripple +5v requlator (ie. 12v input, 5v output) isa better opt ...
上網搵到既降壓線路9成都係7805
1085連影都未見到{:6_136:}
johnnykut 發表於 2016-5-14 07:48 static/image/common/back.gif
上網搵到既降壓線路9成都係7805
1085連影都未見到
7805 is cheap stuff and noisy ! {:1_352:}
you can buy the module came with 7805 and swap it with LT1085 or other quality Linear requlator.
LT108X大電流OUTPUT
7805冇O甘高
johnme 發表於 2016-5-14 11:11 static/image/common/back.gif
LT108X大電流OUTPUT
7805冇O甘高
7805龜殼管出到5A的。
用兩級降壓只係分散熱力，由兩power管分擔，無什麼好處。
用盒仔方式降壓不能得到良好散熱，不能長時間使用。
