Antec Smart Power SL-400 5vsb mod using VIPer 22A

[Khron]

Re: Antec Smart Power SL-400 5vsb mod using VIPer 22A

This is my interpretation of Everell's design. I have not etched it yet but I hope to do so before the end of the week.

You're gonna wanna leave A LOT more space between the drain / "heatsink" area, and the rest of the circuit.

Keep in mind, the drain will be around 325V.

On this page, in the paragraph before the table, you'll find a link to Table I.

Long story short, you want at least 2-3mm between the drain plane, and the nearest "other" copper trace.

HERE's my rendition of the ViPer mod, that i did a couple years back, for my SP-500P

And i also only had 10k resistors handy, and no 9.1k, and my 5Vsb ended up at 5.4v. I could / can live with that, PSU worked fine for well over a year (No, it didn't blow up, it was just overkill for the computer it was powering )

[LDSisHere]

Re: Antec Smart Power SL-400 5vsb mod using VIPer 22A

You're gonna wanna leave A LOT more space between the drain / "heatsink" area, and the rest of the circuit.

Keep in mind, the drain will be around 325V.

Long story short, you want at least 2-3mm between the drain plane, and the nearest "other" copper trace.

Wow, that is some very good information. I really had no idea of the voltages were that high in this circuit. I have not even bothered to look at the VIPer 22a datasheet and my knowledge of power supplies is very minimal. I am working on learning more about them as I go along, but I have a long ways to go. The highest voltages I usually deal with is ~12V and that is directly connected to a voltage regulator to drop it to 5V or 3.3V.

I will rework my design and post the results. Thanks for taking the time to point out my mistake and how to fix the problem. I am sure you prevented me from having a fireworks show that I would not enjoy.

And i also only had 10k resistors handy, and no 9.1k, and my 5Vsb ended up at 5.4v. I could / can live with that, PSU worked fine for well over a year (No, it didn't blow up, it was just overkill for the computer it was powering )

Thanks for this information also. I figured it would raise or lower the voltage but I had no idea of how much or which direction. It is livable but not ideal.

[everell]

Re: Antec Smart Power SL-400 5vsb mod using VIPer 22A

Would you be open to selling me an SMD version? I just bought bulk stock of pick and place excess for pennies on the dollar, I don't know yet what size they are, but I'm betting I can put them to good use in this project.

I think it would be cool if you made a pc board using all SMT components. I would suggest 1206 size lead spacing for the 9.1K resistor, 4935 diode, 10 nF capacitor, and probably the 4.7 uF capacitor which could be a tantalum. Then it would be necessary to drill only the holes for attaching the wires.

[Per Hansson]

Re: Antec Smart Power SL-400 5vsb mod using VIPer 22A

Just thinking out loud; Maybe it would be better to screw the PCB to the primary side heatsink? (Room permitting)
Just to underline the fact that you are working with high voltages?
(And incase something gets loose it's better if it shorts to the primary side vs secondary side)

[LDSisHere]

Re: Antec Smart Power SL-400 5vsb mod using VIPer 22A

I have redrawn the PCB with a minimum 3 to 4mm gap between the drain\heatsink and the other circuits. If I have made any other design mistakes I would appreciate constructive input on what they are and how to correct them.

The entire PCB is 1.25" square if that is important.

I will work on doing a SMD layout after I have this one in good order and Mockingbird knows the size of the components he has purchased.

[c_hegge]

Re: Antec Smart Power SL-400 5vsb mod using VIPer 22A

Now if we can get c_hegge to add a short instruction on how to modify the fans to operate correctly................

Mockingbird beat me to it, but maybe I should add that using a 2.4K resistor in parallel with the fan control thermistor works on both the SP___ and SL___ series. Both obviously have similar fan control circuits, but on the SL, it's built into the main PCB.

[tom66]

Re: Antec Smart Power SL-400 5vsb mod using VIPer 22A

If you are etching that board, I'd highly advise you don't try and route that track through there, it'll merge with everything else... Make the cap spacing bigger (and splay the cap leads), or find another way of routing it -- making the board a little longer would accommodate going behind the connector and cutting the ground plane on the right side.

[LDSisHere]

Re: Antec Smart Power SL-400 5vsb mod using VIPer 22A

If you are etching that board, I'd highly advise you don't try and route that track through there, it'll merge with everything else... Make the cap spacing bigger (and splay the cap leads), or find another way of routing it -- making the board a little longer would accommodate going behind the connector and cutting the ground plane on the right side.

Tom,

I think you may be concerned about my ability to etch the design I posted. I can understand why you would have concerns however this is by far the simplest, least detailed design that I have ever attempted to etch. I figured the easiest way to alleviate any doubts about the etching coming out clean was to make a few of these boards, ten to be exact, and post the results.

I was tying to keep the design as compact as possible to make it easier to fit in the confined space of a power supply. If there is an EE reason to not run the trace through the capacitor legs then I would not hesitate to change it like I did when Khron666 pointed out the high voltage of the drain side. I freely admit to my lack of understanding of how this circuit and power supplies in general operate, this is something I am actively trying to change.

Again, I do appreciate your concerns, if I did not have the experience or equipment to do this then it would be a problem. I have gone through a long learning process to be able to etch detailed boards with consistency.

[c_hegge]

Re: Antec Smart Power SL-400 5vsb mod using VIPer 22A

Nice. That looks good

[everell]

Re: Antec Smart Power SL-400 5vsb mod using VIPer 22A

WOW............cool.................can hardly wait to see one with components..........and working in an actual power supply

When using the copper foil as a heat sink, I would not have all that gap space around the chip pins. If the gap space were eliminated, heat could transfer faster from chip pin throughout the heat sink (on both drain side and ground side)

[tom66]

Re: Antec Smart Power SL-400 5vsb mod using VIPer 22A

Your etching is better than what I have ever seen done. Mega kudos to you, good sir. I was worried, because the results I've seen usually ain't pretty...

[kc8adu]

Re: Antec Smart Power SL-400 5vsb mod using VIPer 22A

nice project.methinks it deserves a sticky.

[LDSisHere]

Re: Antec Smart Power SL-400 5vsb mod using VIPer 22A

Nice. That looks good

Thank you.

WOW............cool.................can hardly wait to see one with components..........and working in an actual power supply

When using the copper foil as a heat sink, I would not have all that gap space around the chip pins. If the gap space were eliminated, heat could transfer faster from chip pin throughout the heat sink (on both drain side and ground side)

When I actually solder the components to the board I intended on filling the gaps with solder and maybe even using solder to build up that entire copper heatsink pad. I will have to mess with the PCB software to figure out how to prevent it from leaving the gaps when I do not want it to do so, I just never had the need before this project.

Your etching is better than what I have ever seen done. Mega kudos to you, good sir. I was worried, because the results I've seen usually ain't pretty...

I appreciate your compliment. The toner transfer method for etching has a bad reputation for a good reason, but if it is done correctly the results can be very good IMO. It takes the correct printer/ink, the correct paper, and a good laminator. I used to use an cloths iron until I wised up and bought my laminator. I would not consider using an iron now except to transfer a silk screen to a board too small to go through the laminator.

I already have the VIPer chips (3) and capacitors, but I will not have the diodes and resistors until Wednesday. Once I get the boards populated I will post those pictures. Just be warned my soldering skill may not be on par with my etching, but it should get the job done.

[everell]

Re: Antec Smart Power SL-400 5vsb mod using VIPer 22A

I think you really created a lot of excitement by adding the pc board project to the original modification description. One of the guys at work was talking with me about it....he was asking lots of questions.....and I didn't have many answers. It would sure be great if you would do a step by step description and walk us thru how you did it. That was a fantastic job you did.

[LDSisHere]

Re: Antec Smart Power SL-400 5vsb mod using VIPer 22A

I received my parts today, so I was able to populate the board I etched. The power supply that I am putting it into needed to be recapped so I spent the rest of the evening working on removing the caps. I still have a few to remove but I ran out of time. The supply I am rebuilding is a SP-450 so I will probably continue in this project in Everell's SP thread that he started prior to this one since it will be more appropriate and less confusing.

[momaka]

Re: Antec Smart Power SL-400 5vsb mod using VIPer 22A

Wow! Very nice project LDSisHere!

[LDSisHere]

Re: Antec Smart Power SL-400 5vsb mod using VIPer 22A

Wow! Very nice project LDSisHere!

Thanks! The project is shown working in Everell's SP-350 thread if you would like to see it.

[momaka]

Re: Antec Smart Power SL-400 5vsb mod using VIPer 22A

I think I saw it earlier this week as I was skimming through the forums. Already added this thread to my favorites.

[everell]

Re: Antec Smart Power SL-400 5vsb mod using VIPer 22A

In retrospect, I went back to a Antec SL400 which had the DM311 5vsb mod to see if it would hold a 2 amp load. Yes it does. The VIPer 22A also holds a 2 amp load. So either chip is a good choice for the SL series. On the other hand, the SP series SMART POWER does NOT hold a 2 amp load with the DM311 but does work well with the VIPer 22A.

I also found a TruePower I had put the DM311 mod in, and it holds a 2 amp load. I also discovered that the TruePower series has the same identical two transistor 5vsb circuit as the SmartPower SL series. So I decided to try something new with a recently acquired TruePower 330 watt power supply. I installed a 5vsb mod board using the NCP1200D6 chip which drives the original FET in the circuit. The original idea comes from a ThermalTake power supply which has a 5vsb circuit rated for 5 amps. My power supply load tester only goes to a 2 amp load, so I do not know what the full potential of this mod will be.

For now, I will include picture of the TruePower 330 with NCP1200 mod, drawings, and a performance sheet showing voltages as measured under test. I don't think a step by step explanation is needed.....if you can do the VIPer 22A mod there is very little difference to doing this one.

[LDSisHere]

Re: Antec Smart Power SL-400 5vsb mod using VIPer 22A

With Everell's help I too have been playing with the NCP1200 and I think it may be the best all around solution to the two transistor 5vsb problem. Since the NCP1200 only drives the original FET it does not generate a lot of heat like the Viper22A does as the real power goes through the FET. The added benefit of this is that the FET is already mounted to a heat sink to disapate the heat it will generate instead of a small PCB being a hot spot in the power supply.