Kevin作者: kk_ho 時間: 2010-12-6 03:19
Feb-2011. Over 1K.作者: roy 時間: 2011-2-1 09:23 本帖最後由 roy 於 2011-2-1 09:26 編輯
Hi,
I am new comer for this Forum.
I saw this topic and had same idea and make my own PSU for my DAC & Headphone AMP.
Just made Dual PSU using LM1085/LM317 with compact metal case.
This is my first prototype. I already made two PCB (one for AC EMI filter, other for regulator parts)
KK.Ho作者: roy 時間: 2011-2-1 13:43
I don't own ND-S1, according to this user manual, their adapter is 5V 1A.
My adapter uses 30W transformer 12VAC. I had VR to adjust output voltage to fit my player.
I use this for my Cambridge Audio dacmagic2 DAC (note :it uses AC12V) & HeadAMP from www. hifidiy.net
, also any portable device such are CD discman, MP3 player etc.作者: roy 時間: 2011-2-1 13:51
LM1085 can give max 3A output where LM317 can only give 1.5A.
If uses 5V output base on 12VAC to DC then I/P to LM1085. It become very hot becasue of high voltage drop. If under 1A continues supply I think it should be acceptable as I am using the metal case as a heatsink.作者: Kchu1377 時間: 2011-2-4 13:23 回復 8#roy
One of benifit to use discrete is high S/N ratio. Normally regulator IC just gives @70dB (max). If good circuit discrete design it can reach higher than this value. However, PCB size will relative bigger because of increase components, typically design using Transistors & OP-AMP as well as reference IC for combinaton
I prefer compact size[mind is @120(L) x 40(H) x 90(w)] and high flexiable, multiple adjust output so that I choose Regulator IC.作者: imtbck 時間: 2011-2-6 18:52
How about 12v >5A DIY Power supply, i wanted to use for my media player Himedia hd800b.作者: roy 時間: 2011-2-16 20:33 本帖最後由 roy 於 2011-2-16 20:36 編輯
Woo, is it really need such high power (12V 5A ~60W)?? It is possible using LM1085 but need a shunt transistor to share some current as LM1085 Max can only give 3A.
Also, Transformer need at least 80W for maintain output if HD800b always eat such high power.
I am under checking on my latest PCB which has shunt transistors for sharing current, now is under evaluation and wait for custom make transformers.作者: imtbck 時間: 2011-2-17 20:07
Hi Roy, thanks for your replied, by the way, may be, i need to measure the ampere of my player and decide the next step... may be on sunday.