Power Supply Question

[SS]

Hi

I have two power supplies giving 110V AC as outputs - I want to connect the
two together in some way so that give 110V output. Can someone pls tell me
how this can be donbe safely. I am trying to create a backup system so if
one fails I can remove one supply and still not disrupt power from system
and then replace the bad one with new. it is like putting two ac sources in
parallel - is that possible



Thx

SS

 

[DAClUM]

"SS" <saleem.qamar@verizon.net> wrote in message
news:l2MYc.2657$Gr2.1015@trnddc07...

Hi

I have two power supplies giving 110V AC as outputs - I want to connect
the
two together in some way so that give 110V output. Can someone pls tell me
how this can be donbe safely. I am trying to create a backup system so if
one fails I can remove one supply and still not disrupt power from system
and then replace the bad one with new. it is like putting two ac sources
in
parallel - is that possible

What kind of power supplies? I assume you are talking about simply a
transformer and not any kind of inverter or switch mode supply.

As long as they are both powered on the same phase you can just connect
there power together and it will work but extremely dangerously and if one
died it would be a miracle if the second didn't go too. If its both
transformers you can usually get away with back to back diodes on each
active wire and join the actives together. But this is really bodgy.

If you give more info about the power supplies we might be able to help but
generally the answer would have to be no.

 

[Chris]

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SS wrote:

Hi

I have two power supplies giving 110V AC as outputs - I want to
connect the two together in some way so that give 110V output. Can
someone pls tell me how this can be donbe safely. I am trying to
create a backup system so if one fails I can remove one supply and
still not disrupt power from system and then replace the bad one
with new. it is like putting two ac sources in parallel - is that
possible



Thx

SS

Hi,
You can't really put two AC supplies in parallel because if they get
out of phase they'll start eating each other's power as fast as they
possibly can and will blow up (but I'm guessing you already knew
that). If you need to put both power supplies together, you could try
to figure out how to phase-lock them. If you just need redundancy,
maybe you should only actually power your circuit with one supply at
a time and keep the other "hot" but not in use; when power fails, you
instantly switch over to the backup supply. If you're just running
lights this'll work fine and you'll hardly notice a flicker, and most
digital electronics runs off DC with its own internal power supply
which can keep it running if the mains supply vanishes for a few
fractions of a second with internal capacitors.

Chris
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