Uninterruptible Power Supply

Posted by PITHOCRATES - February 12th, 2014

Technology 101

The Battery in a Laptop is basically an Uninterruptible Power Supply (UPS)

When working on a personal computer (PC) you’ve probably learned to save your work.  Often.  So if something happens you won’t lose your data.  For there is nothing more frustrating than writing a report off the top of your head without notes only to suffer a power interruption.  And if you didn’t save your work often everything you typed after the last time you did save your work will be lost.  Forever.

Of course if you were working on a laptop you wouldn’t have to worry about losing your work.  Even if you didn’t save it.  Why?  Because of the battery.  Laptops are portable.  We use them often times where there are no power outlets.  Running them, instead, on the internal battery.  Some models even let you change a battery with a low charge to a freshly charged battery without shutting down your laptop.  Which extends the time you can work without being plugged in.

The battery in a laptop is basically an uninterruptible power supply (UPS).  You can work on a laptop while plugged into an AC outlet.  But if someone trips over the cord and pulls it out of the outlet the laptop will switch over to the battery.  And the only way you would know there was a power interruption is if it was yanked off your lap when the person tripped on the cord.  Because thanks to that battery the computer itself never knew there was a power interruption.

The Main Components of an Offline/Standby UPS are a Charger, a Battery and an Inverter

A PC doesn’t come with a built in battery like the laptop.  But we can add one externally.  Which a lot of people have done.  Not only to prevent the loss of data.  But to protect the electronics inside their PC and other sensitive electronic equipment.  Like a monitor.  A cable modem.  A router.  Even a big screen television.  As sensitive electronic equipment can only operate safely in a narrow band of voltages.  And really don’t like things like surges and spikes coming in on the electrical utility line from a lightning strike.  Or under-voltages on hot summer days when everyone in the neighborhood is running their air conditioners.

A UPS can provide a battery backup.  And it can protect your sensitive electronic equipment from surges, spikes and under-voltages.  Which can cause great harm.  Something those surge protected plug-strips can’t protect you from.  They may take a spike or two.  But they are passive devices.  And can do nothing to protect you from an under-voltage (i.e., a brownout).  Only a UPS can.  Of which there are three major types.  Offline/standby.  Line-interactive.  And Online/double-conversion.

An offline/standby UPS is the least expensive and simplest.  The main components inside the UPS are a charger, a battery and an inverter.  It plugs into an AC outlet.  And the devices you want to protect with it plug into the UPS.  If the input voltage (the voltage at the AC outlet) is within a safe range the AC outlet powers your devices.  Also, the UPS controls circuit will monitor the battery voltage.  If it is too low the controls will turn on the charger and it will charge the battery.  When the voltage on the battery is at the level it should be the controls disconnect the charger.  If the UPS controls detect an over-voltage, an under-voltage or a power loss an internal switch disconnects the AC outlet from your devices.  And connects them to the inverter.  A device that converts the DC voltage from the battery into an AC voltage for your equipment.  It will power your devices from a few minutes to up to a half hour (or more) depending on the power requirements of your devices and the battery size.  If the voltage at the AC outlet returns to normal the internal switch will disconnect the devices from the inverter.  And reconnect them to the AC outlet.  If there is a complete power loss you will have time to save your work and safely power down.

The Online/Double-Conversion provides the Best Power Protection for your most Sensitive Electronics

An offline/standby UPS is an efficient unit as it only consumes power when it charges or switches to the battery.  However, switching to the battery every time there is an over-voltage or under-voltage can shorten the battery life.  A problem the line-interactive UPS doesn’t have.  Because it doesn’t switch to the battery every time there is a power fluctuation in the input power.  The line-interactive UPS is basically an offline/standby UPS with an additional component.  An autotransformer.  Which is basically a transformer with a single winding and multiple secondary taps.  If the input power is within the safe range the voltage in equals the voltage out of the autotransformer.  If the input voltage is too high the controls will switch the output to a different secondary tap that will lower the voltage back to the safe range.  If there is an under-voltage the controls will switch the output to a tap that will raise the voltage back to a safe range.  So that these over and under voltages will be corrected by the autotransformer and not the battery.  Which will remain disconnect from the load devices during these autotransformer corrections.  Thus increasing battery life.

The offline/standby UPS is a little more costly but it will have a longer battery life.  And it will also be efficient as it will take minimum power for the controls to switch the taps on the autotransformer.  But if you want the best power protection for your most sensitive electronic equipment you will get that with the more costly and less efficient online/double-conversion UPS.  This UPS is different.  It takes the power from the AC outlet and converts it into DC voltage.  It then takes this DC voltage and produces a pure AC voltage from it.  Free from any voltage irregularities.  Completely isolating your sensitive electronic equipment from the dangers on the electric grid.  For the electrical loads are not normally connected directly to the AC outlet.  They are always connected to the AC output of the inverter.  Which makes this unit the least efficient of the three as it is always consuming power to power the connected loads.

The battery is always connected in the online/double-conversion UPS.  So in a blackout there is no switching required to transfer the loads to the battery. Making for a seamless transition to battery backup.  Of course, sometimes the electrical components inside the UPS malfunction or fail.  In that case the UPS can switch the loads directly to the AC outlet.  Should imperfect power be better than no power.  They will also have an isolation bypass switch.  So you can switch these units directly to the AC source to service the UPS components.  Which may be necessary due to one drawback of the online/double-conversion UPS.  Because the components are always consuming power they generate more heat than the other two types.  Requiring additional cooling to keep these units operating safely.  But they can overheat and breakdown.  Which makes an isolation bypass switch handy to service these while still powering the connected loads.

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Even though Solar Panels and Natural Gas Home Generators allow us to Disconnect from the Grid we Shouldn’t

Posted by PITHOCRATES - April 21st, 2013

Week in Review

I remember losing power for a couple of hot and humid days.  The kind where you stick to everything because you’re just covered in sweat.  Making it almost impossible to sleep.  But I was able to borrow my father’s generator.  So I would not have to suffer through that insufferable heat and humidity.  While I was able to run my refrigerator, turn the lights on and even watch television I could not start my central air conditioner.  Even when I shut everything else off.  It was large enough to run the AC.  But it was just not big enough to start it.  I tried.  But as I did that inrush of current (about 40 amps) just stalled the generator.  Which could put out only 30 amps at 240 volts.  So even though I had a 30 amp generator to start an air conditioner that was on a 20 amp circuit breaker it wasn’t big enough.  Because of that momentary inrush of current.  So I suffered through that insufferable heat and humidity until the electric utility restored power.  And I never loved my electric utility more than when they did.

Now suppose I wanted to go to solar power.  How large of a solar array would I need that would start my air conditioner?  If one square inch of solar panel provided 70 milliwatts and you do a little math that comes to approximately a 950 square-foot solar array.  Or an array approximately 20 FT X 50 FT.  Which is a lot of solar panel.  Costly to install.  And if you want to use any electricity at night you’re going to need some kind of battery system.  But you won’t be able to run your air conditioner.  For one start would probably drain down that battery system.  So it’s not feasible to disconnect from the electric grid.  For you’re going to need something else when the sun doesn’t shine.  And because there can be windless nights a windmill won’t be the answer.  Because you’re going to need at least one source of electric power you can rely on to be there for you.  Like your electric utility.  Or, perhaps, your gas utility (see Relentless And Disruptive Innovation Will Shortly Affect US Electric Utilities by Peter Kelly-Detwiler posted 4/18/2013 on Forbes).

NRG’s CEO David Crane is one of the few utility CEO’s in the US who appears to fully appreciate – and publicly articulate – the potential for this coming dynamic.  At recent Wall Street Journal ECO:nomics conference, he indicated that solar power and natural gas are coming on strong, and that some customers may soon decide they do not need the electric utility. “If you have gas into your house and say you want to be as green as possible, maybe you’re anti-fracking or something and you have solar panels on your roof, you don’t need to be connected to the grid at all.”  He predicted that within a short timeframe, we may see technologies that allow for conversion of gas into electricity at the residential level.

If you want carefree and reliable electric power you connect to the electric grid.  Have a natural gas backup generator sized to power the entire house (large enough to even start your central air conditioner).  And a whole-house uninterruptible power supply (UPS).  To provide all your power needs momentarily while you switch from your electric utility to your gas utility.  Well, all but your central air conditioner (and other heavy electrical loads).  Which would have to wait for the natural gas generator to start running.  Because if you connected these to your UPS it might drain the battery down before that generator was up and running.  No problem.  For we can all go a minute or two without air conditioning.

So this combination would work.  With solar panels and a natural gas generator you could disconnect from the electric grid.  But is this something we should really do?  Not everyone will be able to afford solar panels and natural gas generators.  They will have to rely on the electric utility.  Some may only be able to afford the solar panels.  Staying connected to the grid for their nighttime power needs.  But if our electric utilities cut their generation and take it offline permanently it could cause some serious problems.  For what happens when a day of thunderstorms blocks the sun from our solar panels and everyone is still running their air conditioners?  The solar panels can no longer provide the peak power demand that they took from the electric utility (causing the utilities to reduce their generation capacity).  But if they reduced their generation capacity how are they going to be able to take back this peak power demand?  They won’t be able to.  And if they can’t that means rolling brownouts and blackouts.  Not a problem for those with the resources to install a backup generator.  But a big problem for everyone else.

We should study any plans to mothball any baseload electric generation.  For renewable sources of energy may be green but they are not reliable.  And electric power is not just about comfort in our homes.  It’s also about national security.  Imagine the Boston Marathon bombing happening during a time of rolling blackouts.  Imagine all of the things we take for granted not being there.  Like power in our homes to charge our smartphones.  And to power the televisions we saw the two bombers identified on.  We would have been both literally and figuratively in the dark.  Making it a lot easier for the bombers to have made their escape.  There’s a reason why we’re trying to harden our electric grid from cyber attacks.  Because we are simply too dependent on electric power for both the comforts and necessities of life.  Which is why we should be building more coal-fired power plants.  Not fewer.  Because coal is reliable and we have domestic sources of coal.  Ditto for natural gas and nuclear.  The mainstay of baseload power.  Because there is nothing more reliable.  Which comes in handy for national security.

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Obamacare and the United States Postal Service to have a lot in Common

Posted by PITHOCRATES - May 29th, 2011

Obama Slams the United States Postal Service (USPS)

Back during the Obamacare debates, way back in 2009, the public option was still on the table.  President Obama tried to soothe people’s worry about the public option putting private insurance out of business.  He said it was ridiculous to worry about such a thing.  Because federal monopolies can’t do anything well.  And that private business will always provide a more superior service than a government provided service.  Strange way to advance his case for more government involvement in health care.  But he said it.  And gave an example of a poorly run government monopoly providing no threat whatsoever to its private counterparts.  The United States Postal Service (see The President and the Postal Service by Ed O’Keefe posted 8/11/2009 on The Washington Post).

“I mean, if you think about it, UPS and FedEx are doing just fine, right? No, they are. It’s the post office that’s always having problems.”

President Obama is right.  FedEx and UPS are doing just fine.  And, just as he said, it is the USPS that is having the problems.  As always.  To quote Obama.

FedEx is Profitable

FedEx’s shipping volume in their fiscal third quarter set a record.  And their revenue and margins are looking pretty good, too (see FedEx offers strong outlook for this quarter and beyond by Lynn Adler, Reuters, posted 3/17/2011 on msnbc).

FedEx Express volumes were at an all-time fiscal third-quarter high, and “Ground is knocking the cover off of the ball with both volume and yield gains,” [John Koczara, portfolio manager at AMBS Investment Counsel] said.

“We expect continued positive yield trends to improve revenues and margins in the fourth quarter and in fiscal 2012,” said Alan Graf, [FedEx] chief financial officer.

One thing for sure, it doesn’t look like the public option, the USPS, is giving FedEx any problems.  Confirming what Obama said.  FedEx is doing just fine.  Score one for the private company.

UPS is Profitable

Now, FedEx is good, but there is someone even better.  And it isn’t the USPS (see UPS Profit Tops Estimates, Sees Record in 2011 by Reuters posted 2/1/2011 on CNBC).

United Parcel Service, the world’s largest package delivery company, reported a quarterly profit that beat estimates and forecast record-high profits in 2011, sending its shares up 4 percent.

Doesn’t look like the public option, the USPS, is causing any heartburn for UPS.  Unless they consume too much champagne and caviar courtesy of their record profits.  Score another one for the private company.

The USPS is Sucking Air

With FedEx and UPS booming you’d think that the USPS would be booming, too.  So are they?  Are they posting record profits in the latest quarter?  Not quite (see Sun is setting on rural post offices by Kevin Murphy posted 5/28/2011 on Reuters).

The postal service is losing $23 million a day and is $15 billion in debt, its allowed limit, said Rich Watkins, spokesman for its Mid-America District. The service has cut about 100,000 positions through attrition in the past three years and consolidated sorting and other operations, he said.

The postal service is in such bad financial condition that it may not be able to make a $5.5 billion prepayment for future retiree health benefits due September 30, Postmaster General Patrick Donahoe told a Senate subcommittee last week.

Unlike the private companies, FedEx and UPS, who are doing very well, the USPS is sucking air.  That’s private company: 3; government monopoly: 0.  Which is pretty amazing considering that they have a legal monopoly enforced by the federal government.  Only they can deliver letters.  Unfortunately, they do that so inefficiently that postal customers have found alternatives.

The U.S. agency has lost business to electronic mail and to private sector competitors like FedEx and the United Parcel Service.

That’s the problem with a monopoly.  Always trying to do something the way they did it a generation ago.  Meanwhile, people have turned to email and text messaging.  And paying their bills on line.  Because it’s cheaper.  And easier.  No postage required.  No envelopes.  No trips to the post office.  No muss.  No fuss.  And you can send pictures and video in today’s digital world.  You can’t do that with first class mail.  At least, not with a lot of additional cost.

Of course, they can compete with FedEx and UPS.  Because you can’t send packages electronically.  But the one thing the USPS can do well they still can’t do as well as FedEx and UPS.  We need to fix the USPS.  It needs to be reformed.  To meet the needs of today’s generation.  And tomorrow’s.  But that’s one thing that a government monopoly just can’t do well.  Change.  Or be efficient.  Or provide a service that people demand.

The Public Option will be a lot like the USPS

President Obama was right in 2009.  The government can’t do anything well.  And when they compete against private industry they fail miserably.  In fact, these government run enterprises are so bad that only government intervention can maintain their monopoly.  For awhile.  Because when something is that bad, even government intervention can’t prevent the inevitable.

Which begs the question why did Obama use the USPS-FedEx/UPS analogy to promote the expansion of government into the private health insurance industry?  What’s his argument?  Don’t worry about the public option.  It’ll be as horrible as the USPS that it won’t harm the private insurance market.  But we will pattern the public option after the USPS.  Because only the public option will provide affordable, quality health care.

Yes, the public option will be that remarkable.  It’ll be both horrible and the best thing since sliced bread.  Depending on who the government is talking to at the time.

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