Hardware Secrets Forums


Go Back   Hardware Secrets Forums > Miscellaneous > Content Comments



Reply
 
Thread Tools Search this Thread Display Modes
Old 05-16-2008, 06:07 PM   #1
Hardware Secrets Team
Administrator
 
Join Date Nov 2004
Posts: 5,578
Hardware Secrets Team is on a distinguished road

Default Rocketfish 700 W Power Supply Review

There has been a new article posted.

Title: Rocketfish 700 W Power Supply Review
URL: http://www.hardwaresecrets.com/article/556

Here is a snippet:
"Rocketfish and Dynex are two brands owned by Best Buy sold only on their chain of retail stores (and also on their website, of course). Today we are going to review Rocketfish 700 W, a power supply fe..."

Comments on this article are welcome.

Best regards,
Hardware Secrets Team
http://www.hardwaresecrets.com
Hardware Secrets Team is offline   Reply With Quote
new Sponsored Links

Old 05-22-2008, 06:53 PM   #2
Travis
Senior Member
 
Join Date May 2008
Posts: 84
Travis is on a distinguished road

Default

Quote:
Originally Posted by Hardware Secrets Team View Post
http://www.hardwaresecrets.com/article/556/4

The primary section is controlled two separated integrated circuits, one for the active PFC circuit (ICE2PCS01) and one for driving the switching transistor (i.e. PWM, TNY278P integrated circuit), instead of using just one combo controller as it happens with almost all modern power supplies.
The TNY278P PWM controller chip you saw on the primary side is not the main PWM controller, but the StandBy Power controller.

In traditional half-bridge designs, the main PWM controller chip is usually positioned next to the secondary side to receive voltage feedback directly from the secondary, then the driving transformer is used as the isolator. So the SG6105 you saw on the Dynex 400W and Green Star 450W is the main PWM controller chip (with monitoring/protection circuit integrated).
For that Rocketfish or say Titan 650W, the main controller is AZ7500B
http://www.beareyes.com.cn/2/lib/200...1/DSC_7459.jpg
(AZ7500B is equivalent to KA7500B, or say similar to the TL494 controller
http://www.bcdsemi.com/ProductCenter...ow.aspx?id=205 )

So next time when you autopsy a half-bridge unit, keep an eye on the secondary side and search "494(TL494)", "7500(KA7500B/KA7500C/AZ7500B)", "SG6105" chips. Deer/Solytech loves using an unfamiliar "AT2005B" chip. You can't expect it capable with this strange controller and usually the voltage regulation of this chip is really bad.

Usually Forward design put the PWM chip (ML4800/CM6800G, UC3845B) on the primary side so the PWM signal go through the optical coupler (isolator) and drive the primary MOSFETs. That is often the case in Forward designs.

But still the PWM controller chip can position next to the secondary and receive the feedback signals directly and uses a driving transformer as isolator. Since this approach gets signal faster than optical couplers, it has a faster transcient response.

Last edited by Travis; 05-22-2008 at 06:57 PM.
__________________
Engrish is not my mother tongue.
itocp.com psu editor
Travis is offline   Reply With Quote
Old 05-26-2008, 09:23 PM   #3
Gabriel Torres
Administrator
 
Gabriel Torres's Avatar
 
Join Date Oct 2004
USA
Posts: 4,415
Gabriel Torres is on a distinguished road

Default

Quote:
Originally Posted by Travis View Post
The TNY278P PWM controller chip you saw on the primary side is not the main PWM controller, but the StandBy Power controller.
Thanks, I will edit this review to fix this error.

Gabriel.
Gabriel Torres is offline   Reply With Quote
Old 05-27-2008, 09:57 AM   #4
Gabriel Torres
Administrator
 
Gabriel Torres's Avatar
 
Join Date Oct 2004
USA
Posts: 4,415
Gabriel Torres is on a distinguished road

Default

Fixed, thanks!
Gabriel Torres is offline   Reply With Quote
new Sponsored Links

Reply

Share This Thread

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Forum Jump


All times are GMT -8. The time now is 10:33 AM.


vBulletin Security provided by vBSecurity (Lite) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
vBulletin Optimisation provided by vB Optimise (Lite) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd. ()
2004-12, Hardware Secrets, LLC. All rights reserved.