AC / DC ADAPTER upgrade?

[bohaboha]

Hi I have a power adapter model: 3610 with 36v 1A in output, it is possible to upgrade to 2A if you can tip + can I use for something that needs 2A? hope the pics is clear thank you

[tester272001]

Re: AC / DC ADAPTER upgrade?

Start with checking the rating of those MOSFETs that have heatsinks. Then check the transformer rating. Check the DIODEs for their ratings as well. Those are the man components of concern. I am sure Redwire will have some good feedback too! But this should get you started!

[momaka]

Re: AC / DC ADAPTER upgrade?

More that likely, that would -not- be possible.

Some of these adapters (at least laptop ones) do have current limiting protection (OCP) on the output. They can do a slightly higher "burst" current for a very brief moment without the OCP circuit kicking in... but certainly not continuous.

And even with adapters that don't have OCP, you will still very likely run into the adapter's over-power protection (OPP). After all, 1 Amp @ 36V = 36 Watts. 2 Amps @ 36V = 72 Watts. The designer would have to have been very sloppy to not make OPP catch that kind of difference. And even if they were, you're now drawing 2x the power the adapter was supposedly designed for... so things are bound to overheat and fail, unless the adapter was grossly over-built for its rating... which generally doesn't happen due to costs. In other words, if the adapter could do 2 Amps @ 36V, the manufacturer would have labeled it as such and sold it for a higher price as a higher power output adapter.

[bohaboha]

Re: AC / DC ADAPTER upgrade?

Hi Thanks tester272001 and momaka. so if i have an adapter that has higher curent or 2amps with lower voltage it would be easier to increase the voltage instead? Is it right?

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[eccerr0r]

Re: AC / DC ADAPTER upgrade?

Typically you can tweak a PSU maybe 10% or so off of its original setpoint but realistically they were pretty much set in stone when initially designed. If you need a 36V@2A PSU you may be able to get a 35V or so PSU and adjust up a bit, or perhaps a 40V and go down a bit.

Very unlikely that you can get a 24V@2A and increase it to 36V@2A and still stay stable or leak magic smoke.

[momaka]

Re: AC / DC ADAPTER upgrade?

Hi Thanks tester272001 and momaka. so if i have an adapter that has higher curent or 2amps with lower voltage it would be easier to increase the voltage instead? Is it right?

Maybe, maybe not.
As eccerr0r pointed out above, you can tweak the voltage a little bit, but don't expect to go too far beyond what it was designed for.

Depending on the topology of the adapter, I think 10-15% would be a realistic voltage tweaking limit for continuous-mode topology adapters (ones with an output inductor), and possibly 20-30% with flyback/ discontinuous topology (no output inductor), provided the manufacturer left enough headroom in the latter.

Of course, always consider this: you cannot increase the voltage or the current too much, because the total power output equals voltage times current. Again, the primary side is usually power-limited. Therefore, like eccerr0r pointed out in his example, don't expect to turn something like a 24V 2 Amp adapter into a 36V 2 Amp adapter. Essentially, that's trying to turn a 48-Watt (2 Amps @ 24V) power adapter into a 72 Watt power adapter (2 Amps @ 36V). In some rare cases, if the transformer and the primary switching device(s) can handle it, and if you make proper modifications on the primary side to raise the power limit... maybe you might be able to do that. But again, there are a lot of factors involved here, so it's not a simple question. Generally speaking, though, modifying a flyback / discontinuous topology power supply/ adapter is easier to get higher voltages out, especially if the adapter doesn't have APFC circuit and is rated to accept full range input (95 to 240V AC.) With such adapters, if you run it solely on 220/230/240V AC, you may be able to get that higher voltage output or a good deal above what the adapter is rated for.

[PeteS in CA]

Re: AC / DC ADAPTER upgrade?

There would be potential issues from the output terminals of the AC inlet to the wires to the output plug:

Input rectifier current rating

Switch MOSFET or IC

Current sense resister in the switch source circuit

"Transformer" primary and output winding wire gauge

Output rectifier current rating

Output harness wire gauge

Even current-carrying traces on the primary and secondary sides could have issues

[bohaboha]

Re: AC / DC ADAPTER upgrade?

Hi and Thank you all.It seems that it is better to get a suitable adapter certainly cheaper way