2015-07-02 Power Failure – Clocks

I fell asleep late last night while reading a book*, and I was awakened this morning at dawn when the light went out, my cell phone stopped charging and the screen lit up for a second.  Uh-oh…  A power failure.

Last year during a warm spell, the power went off for many hours.  This time it was from 5:15 to 5:23, or 8 minutes.  Not too long and at a good part of the day, while most people were sleeping.

I have to reset the time on all the electronic gizmos in my home – microwave, old DVD player, stove, etc, etc, etc.  Life is wonderful, with all the high tech things that can’t keep time without electric power.

CLOCKS
A thought crossed my mind.  When I was a kid, and the power failed, when it came back on the clocks, which were powered by the AC line, would start up again and we didn’t have to reset them, if the outage was only a few tens of seconds or less.  However the clock would lag behind the actual time by the length of the power failure.  This meant that you could be late if you didn’t notice the error.  The other edge of the sword was that the clock could tell you the length of the power outage by subtracting its time from the actual time.

Then the genius invented a clock that ran off a small battery and could keep time during a power outage.  And then they made the clock with a quartz crystal, so it kept very accurate time.  Our clocks were then somewhat independent of power failures.

Someone decided to make digital clocks, like the ones in VCRs and DVD players, go to error mode when the power came on. That way, the user would know the time was not accurate. These clocks could have a memory chip, with the power backed up by a small coin cell battery or capacitor, which is the circuit that is used in most computers. But that would be too expensive, so it is not used in most digital clocks, DVD players and other equipment, not counting computers.

There is one easy way of setting the digital clock very accurately. Many of these clocks call it ‘atomic clock’ or something similar. The clock has a radio receiver circuit that picks up the time broadcast by the government on 60 kilohertz. In the USA this radio station is called WWVB and is broadcast from Fort Collins, Colorado. It is a very weak signal and is at a frequency where there is a lot of interference, so digital clocks try to receive this signal when there is less man-made interference in the early morning hours. This can synchronize the clock to within a small fraction of a second.

Digital televisions, DVRs and DVD players can receive the time signal that is sent over the air along with the digital TV signal, so there is no longer a need to set their time.

I guess I should stop this waste of time, get out of bed and make myself useful!

*The book is Merchants Of Doubt by Oreskas and Conway, and is about a small group of scientists who have opposed the scientific mainstream on important subjects, starting with smoking causing cancer, second hand smoke, the ozone layer and ending with global warming. These were eminent scientists who were paid by the tobacco and fossil fuel industries. After reading it, there is no doubt in my mind that their efforts at delaying government regulations have caused millions of deaths worldwide. And sadly, their delaying tactics regarding climate change may cost all of humanity its future.

Leave a Reply

Your email address will not be published. Required fields are marked *

© RustyBolt.Info/wordpress
CyberChimps