Every site should have a Master Clock. This is not a new concept. I learned this fact when I was in the Air Force. Every area had a Master Clock. And each Master Clock had many slaves. In those days, the slaves contained many
digits of Nixie tubes: beautiful orange glowing displays. Those long ago experiances have given me ideas.
Here is my version of a master clock...
This one is built from a PIC (a PIC16C73B from Microchip) microprocessor using bright one inch onboard LED displays.
I have built five clocks that run three sites: Cohasset, Chico, and Tuscan,
all in Northern California. However, an attorney has
has instructed me not to show the racks that contain the clocks. Yet, another attorney has indicated
that this is permitted if there are no descriptions of incidental rack equipment operation.
The primary purpose of the clock is not for people, it is for machines. It is to synchronise, and to relate
the time to other of my devices. And it must be accurate to fractions of a second.
I invented the rotating 1/8 seconds.
In the military - and although displayed - 1/100's of seconds would simply be a blur.
And even 1/10 of seconds were not practical as a display.
Never the less, they WERE displayed!
But my 1/8 seconds in a circle look cool and ARE practical as a display.
I could have used a horizontal display; something like Star Trek's main "viewing screen".
Down at the bottom of that screen, a bar graph would oscillate back and forth.
Also there was a tv series with a black car that has a oscillating bar of lights at the grill.
And before that, there was the movie "The Day the Earth Stood Still" with a robot that had shifty bar eyes
that ominously shifted back and forth. That type of display has been around for a long time.
But I choose
a rotating wheel. I am the first (and only) person, of whom I am aware, that has such a display for
fractions of a second. If you want to bedazzle, then I guarantee that this will do it.
I have two clocks with Green Displays, and one with a green filter.
All other clocks are orange. It is impossible to decide which is prettier; the orange displays or the
green displays. In either case the display uses large one inch digits.
I have designed one RV model for mobile use. Here the display is dimmed and the fractions of seconds are in expensive
cobalt blue LEDs.
The clock is a standard 19 inch rack mount size, done in red oak.
In my system, the master clock is the primary timing source, and keeps all of the community MCU's in time.
The individual PIC microprocessor MCU devices (part of a system) do not keep good time due to the functional time sharing.
I should point out that all of my MCU devices DO have a sence of time - but it is not accurate.
The master clock enables all the inherently inaccurate devices to have access to accurate time.
Many of the PIC MCUs rely on accurate time to accomplish their external functions.
All of the external remote devices can specifically request the time from the MasterClock.
The MasterClock replies to only the requesting device.
the MasterClock is like a beacon, and "squawks" the time to all devices every 15 minutes: once at
one minute past the top of the hour, one at 16 minutes past, one at 31 minutes, and one at 46 minutes.
It is unlikely that any device will be more than a minute off. Time correction must not be made at likely
events. For example the Generator module has responsibility of power generation and is programmed to switch to and from PGE AC Utility power
only at certain times. The "switch" will not only cause the lights to go out, but there will be total
disruption of broadcasting. The switching time must stay out of commercials and IDs. Time synchronization
likewise must stay out of these critical areas. It is better to have a time slightly off, than to cause
a double event or miss an event entirely.
There are times when the MasterClock squawk will be disregarded. For example when a Transmitter-module
is controling the progression of HV equipment. Equipment must be controlled in timed sequence.
This is not the time for a time correction, no matter how small, and the PIC marks out this section
of its internal time as sacred and not subject to change.
I have emphasized anonymity in all my devices, and they practise it religiously.
This is very important. Each Net MCU device utilizes Time Stamping of all messages and communication.
Time Stamping is expected, and is standard procedure. I was the first to use real time stamping
in broadcasting. Until this time, time was only associated with an event at the receiving station or
recording station. I was the first to employ time stamping at the originating remote device.
That first station was Golden Empire Broadcasting in Chico Ca. The year was 1992, and the authorizing
officers were the Executive Vice President, Russ Pope and Station Manager, Dino Corbin.
A master clock is part of a community of devices, which I invented and built in 1992.
The "System", as a whole is important, and not any individual device like the
MasterClock. However the Master Clock is a vital orchistrator for the system to operate.
Standard 19 inch RACK MOUNT.
3 inch high.
Two internal boards, and one external board:
Vertical Display board for the face, and horizontal MCU board, and WWV receiver.
All units were in aluminum.
One vertical display board containing everything except a small remote WWV receiver board.
Some units in wood.
The clock serves a community, establishing accurate time access,
and enables the use of REMOTE TIME STAMPING.
Synchronization to 60Hz AC power...
In the absence of WWV, the clock works by tracking the phase of AC power line 60 Hz,
constantly making very small adjustments to the oscillator.
It has been found by experiment that in a two
month period of observation that the PGE AC service has not lost or gained one second.
This is amazing! And represents a very accurate timing source. But special precautions must be implemented
in the PIC MCU code.
Master oscillator : Free run 5 secs/12hr.
AC: 60Hz short term: approx 1 sec/day
AC: 60Hz long term : approx 0 sec/month
WWVB: aprox 20mS short term flutter drift due to atmospherics and reflections
My MasterClock tracks the drift but does not measure it.
Onboard Digital resolution: 1/8 sec
REMOTE Family resolution: 1/10 sec
Internal resolution: 1/100 sec
Community devices using microprocessors do not choose to have accurate time keeping as their primary occupation. Other devices have
primary tasks that will jeopardize time keeping.
Therefore, the master clock updates other devices (usually PIC16C73B devices) that are inherently inaccurate.
6 large (1 INCH) bright display digits in orange or green.
Hours, Minutes, Seconds. 24 hour format only.
1/8 seconds are displayed in a rotating circular pattern.
This represents the master oscillator segments of 1/8 seconds.
The clock also holds time to 100ths of a second, but transmits time to only a few 10ths of a second
A pulsing led to indicate a timing advancement or retardation to the master oscillator.
Correction is made directly to the 32.768 KHz OSCILLATOR.
A few cycles are digitally added or subtracted to
"phase in" the 32KHz oscillator.
An LED for AC seconds pulse.
for WWV equipped clocks:
An LED for Raw WWV modulation.
An LED for WWV "Zero" data.
An LED for WWV "Ones" data.
An LED for WWV "Mark" data.
An LED for WWV signal loss or data error.
(The indicator LED is the decimal point of the hours.)
an LED for operational Errors: Power loss, or WatchDog Reset
WWVB Day Of Year
WWVB Hour (UCT)
WWVB zero Hundredths of secs
WWVB Leap Year
Day Of Year
Day Of Month
Day Of Week
Hundredths Of Sec
Time: Z (Zulu), NewZealand (zero, NZ)
No MasterClocks contain the sunrise and sunset times. That function belongs to the TOWER MCU.
No MasterClocks contain signoff or signon times. That function belongs to the Transmitter MCUs.
No MasterClocks contain timestamping. That function belongs to all individual MCUs.
No MasterClocks contain telephone calling times. That function belongs to the Phone MCU.
All of the MasterClocks can be seen on a computer screen. And this is despite the fact that the primary
function is to distribute time to remote devices.
Pictured on the computer screen is the first clock that I ever built. It is for nastalgic purposes, and to
allow the user to more quickly identify this module screen. The picture is only a representation,
and is not the actual clock.
The bar graph is interesting...
The bar graph is a record (kept inside the PIC) of WWVB reception. At the top of each hour
a bit is set if the reception has had no errors. It corresponds to the same onboard error indicator. The bits
are shifted each hour and a new bit of information is added.
The new bit corresponds to content errors or timing errors relevent to WWVB reception.
Three bytes are used to represent 24 hours; the last 24 hours from the present hour.
The display shows three hours in which there were errors.
Obviously, the reception here in California is good. However, it is not as good in an RV application.
The two clocks that I have in RVs, one in a van and one in a travel trailer,
have the time in an error state much more.
I do not know if this is from ignition noise or motion multipath.
Unfortunatly, there is one piece of information that is not automatic: TimeZone.
The location must be inputted by a person. Time zone information is manually feed to the MasterClock.
The MasterClock internally holds four times:
WWVB UCT time at Greenwich, Real DayTime at New Zealand, WWVB local time, and Real Display time.
All remote devices get the Display time.
I imagine two other ways to get the location without human input:
One is with an ultraviolet sensor,
attached with several yards of phone cable. With a level,
the sensor is pointed straight vertical. The input would go to one of the PortA pins for an
analog measurement. The pic would evaluate
the time at maximum, and compare the time to WWVB UCT time. With these two pieces of information,
the geographical longitude could be calculated, and thus the time zone.
Makes no difference on latitude or season. With several days of observation, it is bullet prof.
Super easy to implement and calibrate, and would work for moble (car and RV) use too.
The other is with GPS.
Satellites are vulnerable to solar storms, and weapons. I wish not to rely
on satellites. Forget it!
I installed one of my clocks in my RV...
Great copy of Colorado at night.
And this travel trailer has aluminum walls and still receives Colorado just fine.
And the receiver is mounted low on the floor!
... Any where in Northern California and Coastal and Inland Oregon.
I know the exact time no matter where I am at.
Made some changes over the years...
One of the changes is "Sun Rise" and "Sun Set" times.
Years ago, these times were computed by my Tower-Module.
The Tower Module had a light load, and was responsible for only tower lighting and De-Icers.
The Tower Module had room in programing code for a massive "Jump Table", containing all the
Sun Up and Sun Set times for an intire year for the location of the tower.
This was necessary to confirm that all tower lights were on or off at the FAA legal times.
But there are places, like my private home or my RV, where there is no Tower Module.
But I still want to know these times.
But there is not enough room in the Master Clock Module for a massive table.
Logically, the Master Clock was a good candidate to know this information.
I thought about the problem for several weeks, and found a solution:
I invented an "algorithm" to "calculate" the times. It takes far less code.
It all depends on the accuracy that you want. The Table gives times to the minute.
An algorithm gives varying degrees of accuracies
which are proportional to the amount of memory used for the code.
I have about 5 minutes of accuracy with an algorithm. But that is OK in my RV.
Because twelve miles East or West can change the time one minute. So, why fight it?
Here I have added a background image.
This helps to quickly identify which screen is on top, or "Has Focus".
Changes such as these are extremely easy with a high level language: just click the mouse on the object that you want to change.
You can change color, text, size, and countless other things.
Here are four MasterClocks all together.
It is just after midnight, and the signal strength is good from Fort Collins.
There are differences in the clocks:
The top two clocks are slow by about one "LED".
There are 8 display LEDs in one second,
therefore the top, Blue and the Green, clocks are 12.5 mS slow.
Also, the bottom clock and the Green clock do not have their hour's decimal point lit.
The meaning is that they have found a disparity in the information from the last minute.
Previous minutes are artificially advanced minutes to be able to compare with real-time minutes, and in this case there was an error.
It can also mean that a Mark was not received on one of the 10 second intervals.
It can also mean, and this is probably the case, that a "Double-Mark" was not received at the top of the minute.
The criteria for a Double Mark is quite stringent.
Each Mark of a Double Mark has quite different criteria; They have to be almost perfect.
The top clock, in Oak, can mount into a 19 inch rack.
The two shorter clocks can "set" in a 19 inch rack on a shelf.
I do not know what to do with the third clock down, as it is a box with no ears.
The antennas can no longer be bought at DigiKey. No antennas can be bought at DigiKey.
In fact, C-Max no longer supplies 60 kHz antennas. But another company out of Canada will supply you with this antennas.
They can supply any quantity that you want. The company: Symtrik.
Symtrik can supply Receiver Modules SYM-RFT-60.
Symtrik is a company that is responsive, accommodating, and easy to work with.
Originally, Daylight Savings Time was designed to help school children.
No one wants a child to be traveling in the dark. But government has Micro Managed
the schools to the point of being ridiculous and burdensome.
(I think Benjamin Franklin was the first to advocate "sun management" and
changing activities, not the damn
In the old days it was quite different:
Originally, the principal of each local school
had the management duties of deciding, at a local level, of when to have children begin classes.
The power should be returned to the principal, as it is in some states like Hawaii.
The principal - if he or she had the notion - simple sends a note home stating:
"Beginning in March classes will start at 8:00 instead of 9:00. Thank you. Your principal"
"Only a white man would believe that you could cut a foot off the top of a blanket
and sew it to the bottom of a blanket and have a longer blanket."
- An American Indian
The same can also be said about local businesses: The boss, or employees, can decide on what time
to go to work; NOT the Government! Do we want to go to work at eight, or do we want to go to
work at nine? ...Or maybe at eight thirty. And as a plus, and unlike our sister company,
perhaps our company could save some money!
We are uniquely in a position to best know, not the
Over the years, Daylight Savings has caused havoc with my control systems; with arbitrary rules.
Politics has been
interfering and forcing me to accommodate science with a totally asinine political notion.
For example: Did you know that
sunrise and sunset times from year to year hardly change at all - EXCEPT for daylight savings time?
My devices are literally crying out: "What is going on with the time?" Sadly, I can not explain
it to them.
Over the years, my official FCC forms have been printed in Daylight Savings time to abide to convention.
I have angrily stayed in line. But I think I will cancel all printing of Time in this format. From now on! Some one must stand up to this insanity!
All the clocks located in the White House should be set to daylight savings time, and all the rest of the
clocks in the world should be left alone. Forever! Deal with it!