Artesyn NLP65 series schematic

[orgwood]

I've got several NLP65-7629s that have 2 power rails - 5VDC and 12VDC. I've looked everywhere but cannot find a schematic. I contacted their support and was told it's proprietary...I said what's so special about a SMPS that it's secret? So here's what I want to do...I have a need to modify the 12VDC rail to output around 20-24VDC. The voltages look okay on the caps and looking at generic SMPS designs, the only components setting the second rail voltage seems to be a series/parallel Resistor combo that determines the tolerance too. Those SMT resistors seem to be on a module that is vertical and is soldered to the main PC board. So I'm thinking that if I can find out which resistors set the 12VDC rail, I can just cut the sense trace from that output and insert another resistor to up the voltage into my wide tolerance goal. Any one who can help find that schematic or who has any ideas about the changes I plan good or bad? Thanks, Dave

[budm]

Re: Artesyn NLP65 series schematic

Can we see good clear pictures of the board?
I doubt very much that you can modify 12V into 24V, also as Voltage goes up the output current capability will go down.
The filter cap rating will also need to be changed to 50V.
There should be a ref diode like TL431 on the secondary side with resistors to regulate the output Voltage.
The 5V output will also go up when you modify the circuit.

[orgwood]

Re: Artesyn NLP65 series schematic

Hi budm, thanks again for your interest. I'm going to try to post some pics and a link to the sales brochure -

https://cdn.badcaps-static.com/pdfs/...272a9aaa7b.pdf

This one chassis can be both 5 - 24 & 5 - 12 with many other variants. I've looked at several different ones and it seems they use a main PC board and modify the personality module for the variants. The 12 V section caps are rated at 35V so they might be OK since I really don't need to go completely to the top end of my range. My Rockwell AIM-65 printer has an on-board regulator for both motor voltage and print dot density so getting to around 20 V should be good enough.l But I do need to stay at the 5 VDC. The rating on the 20 V rail is well under the continuous duty rating of this supply. Do you need to see more? If so, I can try to get it for you.

The pics are of my NLP65-7629 and the other is one I pulled of the internet for a NLP65-7608 I believe.

Dave

[orgwood]

Re: Artesyn NLP65 series schematic

Hi Bud, I went to your photo displays and enjoyed viewing the various conditions described by the titles there...I've seen a few of those in various repair projects before. I'd advise anyone looking for examples of known types of electronic failures to take a look.

I work on just about anything that is broken and cheap to buy so my investment in my education remains low...at 68 years old, I want to stay current with my skills but also use the more current technology without being considered a rapid adapter.

So I want to thank you for your patience and considerable expenditure of time and effort to mark up the schematic showing me the theory of operation of that Philllips SMPS board I was working on. The theory meant more to me than other things I found on the internet and allowed me to "see" how the supply became active via the standby pin.

This new thread about the Artesyn NLP65 series is just a takeoff on the Phillips output design so I thought modifying the series resistor combo would allow me to raise the output voltage from 12 to 20-24 VDC that I'm looking to get out of it. I think your points about power dissipation are well taken and very important since there is a 65 watt limit on the total ambient power supply dissipation in free air - 75 watts when in a forced air environment. Thanks for any help you can offer.

[orgwood]

Re: Artesyn NLP65 series schematic

Can we see good clear pictures of the board?
I doubt very much that you can modify 12V into 24V, also as Voltage goes up the output current capability will go down.
The filter cap rating will also need to be changed to 50V.
There should be a ref diode like TL431 on the secondary side with resistors to regulate the output Voltage.
The 5V output will also go up when you modify the circuit.

If there are 2 reference diodes on the secondary side, one for each rail, why would the 5V output go up when I modify the 12V rail?

[budm]

Re: Artesyn NLP65 series schematic

Only one ref diode for the feedback function, some power supply only detect the 5V output to do the regulation, some detect both 5V and the 12V lines by feeding the ONE ref diode.
You only have one transformer with two windings you cannot drive the primary side more without making the two secondary windings to go up at the same time.
See example of the detection of the two outputs, HP W1907.
And single detection QT94.
Just do the research on how transformer operates.

[orgwood]

Re: Artesyn NLP65 series schematic

That makes perfect sense since I now understand that the primary side is being driven so both secondaries must rise proportionately. So would it be correct to assume that there are different transformers for the different models? That would mean that I cannot do what I want to do unless I can remove/add windings from the secondary and they would have to be the correct rail and situated so I can get to them. It doesn't sound practical. If I wanted to drop a higher voltage, I might add a 3 terminal regulator if it could handle the power dissipation but again, that doesn't sound like the right move either. Thanks again for your insights. Dave

[budm]

Re: Artesyn NLP65 series schematic

Please see the updated post with the added diagram for typical SMPS.
BTW, you are only 7 years older than me, so there is no time limit for learning, I enjoy it very much everyday.

[orgwood]

Re: Artesyn NLP65 series schematic

If the transformer had different taps on the windings both secondary and primary, maybe I could find the combination they used for their different models but I think that is not the case since the board layouts look identical for all models. Therefore, I conclude the transformers are different for each model. Thanks again and I looked at the schematics you posted.

[orgwood]

Re: Artesyn NLP65 series schematic

In case anyone else runs into this problem, I've decided to add a stepup module that takes either the 5V or 12V rail and increases that voltage to my desired 24V. These modules are inexpensive and let me keep my 12V rail for future use but give me the 24V rail needed to run the AIM printer.