How many milliseconds is too many milliseconds?
- Thread starter carbon60
- Start date
Laptops will be fine, a desktop is hit and miss and I don't think anyone could tell you for sure. If you do the math I think it might be close. A 60 hertz sine wave transitions from power to no power about every 7 milliseconds. Most have a switching power supply that contains at least some capacitors that even out power to the motherboard providing some measure of safety.
The final choice would be on you to take a risk that a spike in power won't be absorbed by your equipment and it gets toasted. I have some equipment that can handle this kind of switching, but others that were fried when switching from generator to shore power.
The final choice would be on you to take a risk that a spike in power won't be absorbed by your equipment and it gets toasted. I have some equipment that can handle this kind of switching, but others that were fried when switching from generator to shore power.
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Finlay
Triarius
It depends on the computers. Laptops will likely be fine, but buy a spare power brick ahead of time. Desktops....
I used to work for a company that stacks of computers in vans to collect data (Think Google street view, but bigger and better). We ran the computers and equipment off good UPS's, because almost all inverters are noisy as hell, and some produce very, very bad AC waveforms. Most switching power supplies in computers do poorly with crap input. A good - not inexpensive - UPS from TrippLite or APC can deal with that and outputs a nice steady waveform no matter how bad the input.
I used to work for a company that stacks of computers in vans to collect data (Think Google street view, but bigger and better). We ran the computers and equipment off good UPS's, because almost all inverters are noisy as hell, and some produce very, very bad AC waveforms. Most switching power supplies in computers do poorly with crap input. A good - not inexpensive - UPS from TrippLite or APC can deal with that and outputs a nice steady waveform no matter how bad the input.
DiploStrat
Expedition Leader
When is an UPS not an UPS
Do remember that most consumer grade UPS are not true UPS. A true UPS always outputs its own sine wave power from its batteries or a motor-generator. Most consumer units, like those made by APC, actually run on city power until there is a failure and only then switch to their batteries and an inverter. The switch time runs around 10-30 milliseconds.
It would thus seem that the inverter/charger in question has a transfer time in the same range.
But more to the point, my Magnum inverter/charger has at least a 30 second diagnostics/warm up period before it begins inverting, so it makes no attempt to provide uninterrupted power.
Do remember that most consumer grade UPS are not true UPS. A true UPS always outputs its own sine wave power from its batteries or a motor-generator. Most consumer units, like those made by APC, actually run on city power until there is a failure and only then switch to their batteries and an inverter. The switch time runs around 10-30 milliseconds.
It would thus seem that the inverter/charger in question has a transfer time in the same range.
But more to the point, my Magnum inverter/charger has at least a 30 second diagnostics/warm up period before it begins inverting, so it makes no attempt to provide uninterrupted power.
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That's a "line-interactive" UPS. I've seen claims of anywhere from 2 ms to 20 ms.
My question is really whether 2 ms is required or 10 ms will suffice, I guess!
Thanks for all the feedback,
A.
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