A Look Inside

Before reading this page we strongly suggest to take a look at this article, which will help you understand the internal components of a PSU much better.


The OEM of all VPx50P PSUs is Delta, a highly experienced OEM which has close co-operation with Antec and has built many top class PSUs under Antec's name (the mighty HCP-1200 is one of them). The main PCB is significantly underpopulated and the heatsinks (primary and secondary) are small, since the unit doesn't have increased thermal dissipation due to its restricted capacity. In order to provide you a better view of the internals we desoldered the secondary heatsink.


The transient filter starts right at the AC receptacle with a pair of Y caps. The power cables are wrapped around a ferrite ring before they reach the main PCB. The second part of the transient filter consists of two CM chokes and two pairs of X and Y caps. Unfortunately there is no MOV present. As it seems Delta stopped using MOVs in their entry level designs and we simply cannot understand why.


The bridge rectifier (T6KB80) is not bolted to a heatsink, since at worst case it will handle around two Amperes only (2A x 230V= 460W) while it supports up to six (in a limited temperature range). The 100Hz fully-rectified signal is filtered by an X capacitor before it enters the APFC circuit. In the APFC one ΤK12A50D mosfet and the essential boost diode are used. The hold up cap (450V, 220μF, 85°C) is provided by a not well known manufacturer, called Elite.


The main choppers are two ΤK12A50D mosfets.


The combo PFC/PWM controller is a FAN4800A which is soldered on the component side of the main PCB. The PWM standby controller is a TNY278PN, the same used in the bigger VP550P.


The protections IC is a DWA106 which is also supported by a AS393D dual voltage comparator.


In the secondary side group regulation design is utilized along with passive components. Definitely not the best combination but with this price tag you can't ask for more. The +12V rail is regulated by two SBR20A100CT, 5V by two MBR2045CTG, 3.3V by an STPS3045CT and another MBR2045CTG handles 5VSB. In the secondary heatsink we also found an NTC (Negative Temperature Coefficient) thermistor which is used for the fan's speed control. An NTC is a component which changes its resistance when there is a change in its temperature.


A very weird mix of capacitors is used in the secondary side: Rubycon, Nippon Chemi-Con, Teapo, Taicon and Ltec. Probably Delta picked some from the bag and installed them in the unit, because we can't think of any other reason to use so different, in quality, caps. Thankfully all are rated at 105°C.


In the component side of the main PCB we located the two shunt resistors, which provide information about the power drawn from +12V. They are part of the OCP (Over Current Protection).


Soldering quality is impeccable, something typical for Delta made units.


The cooling fan is provided by Yate Loon and its model number is D12SH-12 (12V, 0.3A). In this unit, contrary to VP550P which uses the same fan, it doesn't output significant noise even at full load with high ambient temperature. Probably Delta restricted its max RPM because the VP350P has much lower thermal dissipation compared to VP550P.