sps80 testing report

在無負載時輸出有 120多V
在負載電流 0.2 A時，輸出電壓118.3V
在負載電流 3.7 A時，輸出電壓仍保持在118V 左右，不過隨隨著溫度昇高，電壓也在大約30分鐘後昇至 121V。這時鋁板溫度 62度，Inrush limiter 温度約70度，輸入電解 680uF電容也頗熱，估計有 40幾度，那3300uF 電容只發出微温，火牛也是很熱的，估計有五十幾度。
#測試時散熱只靠本身的鋁質底板，完全沒有外加散熱器。

下圖那些是 170Khz Pluse，明顯是來自那85Khz 電源橋式整流後的，加上單邊Choke後分別不大，波幅大概是2V 左右，但正負各加一只Choke，Pluse確是明顯減少，再在兩個Choke後並上一只0.47u電容，Pluse就更少，而且170khz已遠離人耳可聽見的頻率範圍，因此不應有什麼影響了。在負載 3.7A時火牛開始發出噪音，但只是很少的噪音，據報這火牛芯是特別設計成鬆鬆的，所以有點聲音也是正常的。



在煲機約 30分鐘後關機，不過就不能再開機，差不多半個小時後才可以再開。這是因為組模過熱，觸發了保謢電路，若用在後級上不至於長期用上這麼大的負載，只要把模組按裝在機箱上散熱，問題應可解決，若用在A類機身上想必要加上風扇才行。


差不多是2V的振幅



正負輸出端加上Choke後振幅減至1V左右


在Choke後再加上0.47u電容，Pluse幾乎不見了，在3.7A負載下，那紋波電壓只剩300mv，十分漂亮吧！

ackcheng hing, are you using it to power the UcD400 modules? If so, how do you find it compared with linear power supply? Do you mind sharing your experience?

I found the bass with SPS80 tighter, faster and more punchy. But the linear power supply gives a smoother less fatique kind of sound

achcheng hing, thx for the reply. I plan to use a very simple psu - toroid with dual secondaries, dual bridges, 2 x 10,000uf filter caps per rail (no bypass caps either for the rectifiers or the filter caps, no snubbers, no bleeder resistors). Bruno seems to favour a simple psu.

I have not yet settled on the actual choice of the rectifiers and filter caps. For the rectifiers, I may use MBR10100 x 8 or IXYS bridges x 2. Caps may be Epcos Sikorel or Jensen 4-pole (or BHC if I can find them). What do you think of this setup? Did you end up with Coldamp SPS80 or a linear power supply? If it's the latter, what are your component choices? Many thanks.

I think both rectifiers you mentioned are good. For filtering caps i tried RIFA but not good. Now I am using hypex stock power supply with BHC slit foil. I also tried Sikorel and is really good. I already have 2 mono UCD400AD with linear power supply. I am now building a HT system so I want to use SPS80.

In fact, I have 2 x 1500W transformers already for (UCD400) but it is too big for me. If you want I can also sell it to you!

BTW, I think it is safer to use bleeder resistors.