|05-16-2008, 06:07 PM||#1|
Join Date Nov 2004
Rocketfish 700 W Power Supply Review
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Title: Rocketfish 700 W Power Supply Review
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.
Hardware Secrets Team
|05-22-2008, 06:53 PM||#2|
Join Date May 2008
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
(AZ7500B is equivalent to KA7500B, or say similar to the TL494 controller
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
|05-26-2008, 09:23 PM||#3|
Join Date Oct 2004