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

[everell]

Here is a step by step instruction for the Antec Smart Power SL-400.....eliminating the two transistor 5vsb circuit and installing a VIPer 22A pwm chip. The SL series is a current forward design rather than the less efficient half bridge. This modification can be done without removing either of the heat sinks. Pictures show the end result. Also a schematic of the original two transistor circuit and a schematic of the modified circuit using the VIPer 22A.

[everell]

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

First step, build the add on mod board using commonly available perf board. Radio Shack sells this in 4 inch by 6 inch sheets. The schematic is shown using different colored wires to make assembly much easier. Pictures show top side of the board and bottom side of the board. There are only 5 parts used, a VIPer 22A chip, a 9.1K quarter watt resistor, a 1N4935 (or equavilent) high speed switching diode, a 4.7 uF/50 volt electrolytic capacitor, and a 10 nF film capacitor (usually marked 103).

[everell]

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

Next step is to remove jumper J2. One side of this jumper goes to the collector of the 5vsb switching transistor. The other side of the jumper will be used for attaching the red wire which goes to the drain of the VIPer 22A pwm chip. Removing the J2 jumper removes the switching transistor from the new circuit so that you don't have to unsolder it and remove it from the heat sink.

[everell]

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

Next remove Resistor R19. This is the startup resistor which provides the startup voltage to the two transistor circuit. Removing this resistor assures that no accidental startup problems occur.

[everell]

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

Next remove Coil L2. One side of this coil location will be used to provide the Vdd power to the VIPer 22A chip. The yellow wire will be be attached here a few steps from now.

[everell]

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

Now remove transistor Q5. The emitter of Q5 is grounded, so this ground location will be used to attach the green ground wire to the VIPer 22A mod board.

[everell]

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

Next remove Resistors R22 and R23. This will remove the optocoupler from the old two transistor circuit and give you the holes for attaching the blue and brown wires to the VIPer 22A mod board.

[everell]

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

Now it is time to work on the bottom of the power supply pc board. Attach the red wire to the hole formerly occupied by jumper J2 and as shown in the picture.

[everell]

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

Next attach the yellow wire using one of the holes formerly occupied by coil L2 as shown in the picture.

[everell]

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

Next attach the green (ground) wire to the hole used by transistor Q5 emitter as shown in picture.

[everell]

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

Finally, attach the brown and blue wires in holes formerly occupied by Resistors R22 And R23 as shown in picture. Also, you will need to make one circuit trace cut as shown in the picture. This will prevent voltages from going back into the two transistor circuit.

[everell]

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

Check your work carefully to be sure you have no solder bridges. A small brush and alcohol can be used to clean the area you have been working on. Pictures show the 5 wires going from the VIPer 22A mod board to the main pc board and how I mounted the mod board to one of the heat sinks. You are now ready for smoke test!

[mockingbird]

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

I'm glad you reported back with the ultimate success with the Viper 22A on the Antec after you indicated erratic results in a previous thread. I want to carry out this mod, is the SL400 similar enough to the SP450 so that your instructions will work for this model too?

[LDSisHere]

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.

[mockingbird]

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

You're gonna etch it with the laser printer/acid/copper method?

[LDSisHere]

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

You're gonna etch it with the laser printer/acid/copper method?

Yes, that is the method I normally use.

[mockingbird]

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.

[everell]

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

Here is a picture of the Antec SL-400 (front) and SP-350 (back). This shows the difference in the pc boards of the Smart Power SL series and the SP series. Both are sporting the VIPer 22A 5vsb modification. Now if we can get c_hegge to add a short instruction on how to modify the fans to operate correctly................

[mockingbird]

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

Here is a picture of the Antec SL-400 (front) and SP-350 (back). This shows the difference in the pc boards of the Smart Power SL series and the SP series. Both are sporting the VIPer 22A 5vsb modification. Now if we can get c_hegge to add a short instruction on how to modify the fans to operate correctly................

Ok, so I should look at the SP350 mod thread...

BTW, he already has described his mod:

It's different for every fan controller, but I usually find out by temporarily soldering a Trimmer Pot in. Tweak it until you find a good idle speed, and once you're happy with it, remove it and measure the resistance, and find a resistor which is approximately what you had the pot set to, although be careful not to move the knob when you're removing the pot. I have one on a plug which I use for testing, so I can just unplug it when I'm done testing, and then unsolder the plug from the PCB. Since my plug is on wires, which I can have away from the PSU, it also saves having my hands too close to live components.

EDIT: FWIW, It's about 2.4K for Antec Smartpowers, but In another PSU (similar to https://www.badcaps.net/forum/showpo...&postcount=103), it was about 6K.

[LDSisHere]

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

First step, build the add on mod board using commonly available perf board. Radio Shack sells this in 4 inch by 6 inch sheets. The schematic is shown using different colored wires to make assembly much easier. Pictures show top side of the board and bottom side of the board. There are only 5 parts used, a VIPer 22A chip, a 9.1K quarter watt resistor, a 1N4935 (or equavilent) high speed switching diode, a 4.7 uF/50 volt electrolytic capacitor, and a 10 nF film capacitor (usually marked 103).

What would be the result of using a 10k resistor instead of the 9.1K? I already have 10k but I would have to order 9.1K. No major deal, just not convenient.

Thanks,
Lloyd