Maker Pro
Maker Pro

Chaining up multiple redundant power supplies

E

Ed Kane

Are there any devices available on the market that will allow me to hook-up
multiple redundant power supplies to provide higher wattage outputs and
better power redundancy.



Something like chaining up four of the following 3x225W (N+1 450W) redundant
power supply together to provide >1800W of total power.



http://www.rackmount.com/Rackacc/RP8450.htm



Has anyone done this before?
 
J

John Tserkezis

Ed said:
Are there any devices available on the market that will allow me to hook-up
multiple redundant power supplies to provide higher wattage outputs and
better power redundancy.

There would be nothing available "off the shelf" to adapt normal power
supplies, as the load sharing is integral to the power supply design itself.
Or, if it isn't already, it needs to be.
Something like chaining up four of the following 3x225W (N+1 450W) redundant
power supply together to provide >1800W of total power.

While you might be able do that, keep in mind its true value comes from the
redundancy. So you're limited to total shared power minus one unit. Obviously
more beneficial with more than two units in that case.

Further chaining existing redundant supplies might be easier, but you have to
work out how they've done it, and adapt that. Not only that, in your above
case, it would be better to start off with higher power units, as using
multiple (well, more than three) power supplies over your entire load ends up
being expensive.

The situation gets more complicated if the power supply has post regulated
outputs. You have to share those loads separate from each other. There is
also the requirement of all post regulated outputs being able to be controlled
in a similar manner, and this is not always the case depending on design.
Has anyone done this before?

I've had been seriously looking at doing it "on the cheap", but once you
factor in the extra tray connectors, time and money spent, it ends up much
easier and cheaper to just buy it outright.

Though, the cool frankenstein factor would be great value amongst our geek
friends...
 
A

Allan Herriman

There would be nothing available "off the shelf" to adapt normal power
supplies, as the load sharing is integral to the power supply design itself.
Or, if it isn't already, it needs to be.

The outputs can be adjusted if the power supplies have been designed
with load sense wires. Many power supplies and power supply modules
have this feature.

There are lots of load share controller chips available, from ST, TI,
Linear Tech. etc.
These will use the power supply sense lines to adjust the output
voltage of each supply so that the load current is shared.

Regards,
Allan.
 
J

John Tserkezis

Allan said:
The outputs can be adjusted if the power supplies have been designed
with load sense wires. Many power supplies and power supply modules
have this feature.
There are lots of load share controller chips available, from ST, TI,
Linear Tech. etc.
These will use the power supply sense lines to adjust the output
voltage of each supply so that the load current is shared.

You're right. I've looked it up soon after sending that message. All you
need is a current sense resistor on each output, a shared line, and control of
the regulator feedback.

Though, I don't see any DIY "neat" solutions, unless you're adapting some
other type of cabinet or enclosure..

I've just checked up on prices here in australia, and they don't look
favourable. They stand at about three times the price of two "normal" power
supplies on their own.

Looks like I'm going to have to 'jim robinson' something up myself after all.
 
Top