Presentation on theme: "Telechron Master Clocks and Time Distribution"— Presentation transcript:
1Telechron Master Clocks and Time Distribution Mitchell JanoffOctober 2003
2Largest Blackout in US History Affects over 50,000,000 People and 9,300 Square Miles August 14, 2003: Blackout in the northeast effects 50 million people over 9,300 square milesRipple affect due to the interconnection of power plants across US and Canada cause of problem.
9So what does this have to do with Henry Warren???? Henry Warren is responsible for the modern International Power Grid due to his early work in:Frequency stabilizationTime distributionClock synchronizationInterconnection between power stations
10Henry Warren and the Introduction of Synchronous Timekeeping How did Warren revolutionize timekeeping in the USWhat obstacles did Warren overcome to accomplish his goalsHow does the synchronous self-starting AC motor workHow did Warren help power stations to maintain 60HzHow did Warren convince the power generating companies to adopt his technology
11What is the Function of a Clock? There are two distinct function of all clocks:1. Measure time as accurately as possible, and2. Tell time with the greatest possible convenience
12What is the history of telling time? Very early clock makers recognized the desirability of telling the time over as wide an area as possible.Early clocks were typically equipped with bells to toll the hours.Now we need to know minutes and seconds in addition to the hours.
13Time has been Distributed Locally Throughout History Tower Clocks began distributing time in the 1300’s.By the 19th century, the industrial revolution had made tower clocks regular features on factories and railroad stationsStandardize timekeeping across the United States is just over 100 years old.MetLife Clock Tower New York City
14Western Union and the US Naval Observatory Begin a Time Service in 1865 First locally to Washington, DCBy 1869 to the B&O RailroadIn 1877, Western Union initiated its national time serviceIn 1886, Western Union’s time service delivered both time and timepieces.
15On November 18, 1883 Standard Railway Time went into effect in North America Standard Time Replaces Local Time and Railroad Time, each determined by the position of the sun in a community or region.Most large cities immediately adopted the railroads’ time systemUnited States is divided into four time zones based on the Prime Meridian in Greenwich, England.
16The Naval Observatory and Western Union Lead the Way in Time Distribution Western Union’s time ball in New York City fell to inaugurate Standard Railway Time based on a signal telegraphed from the U.S. Naval Observatory 240 miles away in Washington D.C.Western Union also flashed a time signal across the country over its network of telegraph lines.
17Time Signals were Distributed Hourly on the Hour Clocks were supplied by the Self Winding Clock Company of New YorkMaster clocks in the Western Union network were automatically corrected once a day at noon.Western Union’s low cost and nationwide distribution quickly drove the competing time services out of business.
18The Standard Time Act of 1918 made Standard Time a Federal Law Standard Time introduced a need for synchronized timekeepingThe United States Naval Observatory is chosen to maintain and distribute the time due its long history of time distribution.Clocks throughout the United States now differ by only the hours.
20Western Union Time Service is aimed at Municipalities and Businesses Time Service to Individuals is not as well developed.In 1883 John Oram, a Dallas Jeweler applies for a patent on the “Oram Time Machine”, the “Oram Time Regulator” and the “Oram Time Indicator”.Oram’s system signaled the time of day continuously via a system of coded pulses heard over the receiver of a telephone.
21Time Distribution over Telephone Lines Fails to Generate much Interest Equipment was expensive for exchanges ($5,000+)Customers refused to pay for a time serviceBell did not encourage its franchise holders to make time a fundamental part of the telephone business*Picture from: Selling The True Time Ian R. Bartkey, Stanford University Press Stanford CA 2000
22Master/Slave Clock Systems were introduced around the turn of the Century Advantage of having all clocks in a building synchronizedBattery powered and all connected to a master eliminated the need to set clocks individuallyRequired separate system of wires
23How was Time Distributed? Primary distribution via Telegraph from 1890USNO Begins Radio Time Distribution in 1904By 1923 Fourteen Stations are in Operation across the USPicture from: Time and Timekeepers, Willis I. Milham, The Macmillan Co 1941
24What’s Going on with Electric Clocks in the Early 1900’s? Electric Clocks weremore costlymore delicatemore likely to get out of order, andNo better time-keepers than common varietyWhile they didn’t need winding, batteries were somewhat uncertain in durability.
25Warren’s Attempts at Electric Clocks Warren files a patent for battery clocks in 1908Started as a hobby, led to a small businessBy 1916 Warren realized that the battery clocks would never be a commercial success
26So what Problem is Henry Warren Solving? While all clocks within the same time zone should read the same time, each clock operates essentially independently.Clocks need to be wound, and set frequentlyElectric clocks are unreliable and no more accurate than wind-up clocksMaster/Slave clocks solve some of the problems, but are expensive and complex
27Why Adopt the electrical Network for Timekeeping By 1916 there were two independent networks connecting people in the US.Telephone network connected the well-to-do and officesThe light and power lines covered a more extensive territoryBy 1916 More than 90% of all electric light, heat and power was distributed in the form of alternating current.People were thinking about using the electrical network for timekeeping; nobody did anything about it.
28Warren is the First to Develop a High Torque, Self-Starting, Synchronous Motor 1918 Warren Patents the self starting synchronous motor after years of experimentation with various technologiesType A is an enclosed movement rotating within an electrical field
29The Telechron Motor is the Best Self-Starting Synchronous Motor Motor is small and compactComes to full speed, under rated load, instantaneously with no measurable lagSelf-lubricated, rotating parts entirely enclosedUnaffected by changes in voltage, current, or temperatureCan be made to operate on any commercial frequency or voltage
30Front view of type A motor with bottom cover removed Front view of type A motor with bottom cover removed. The vertical worm gear's arbor extends upward to the top and carries the rotor, which rotates at 3600 RPM. This worm engages with the 75 tooth brass gear which carries the second worm gear. The second worm drives a 48 tooth gear which rotates 1 RPM. The 48 tooth gear is mounted on the arbor which carries the output pinion on the front of the motor.
31Bottom view of type A motor with bottom cover removed Bottom view of type A motor with bottom cover removed. The body of the gearbox is made of die-cast material.
32Telechron Synchronous Motor Previous MotorsSelf-Starting but low torque or not synchronousManual-Starting but high torque and synchronousTelechron MotorHigh Torque, synchronous and self-startingSingle Phase Motor can be installed directly on the power lines in most homes and businesses
39Early Experiments in 1916 with A-Motor Uncover Problems First experiments show clock to to gain or lose as much as minutes each day.Warren calls Boston Edison and reports frequency is off by approximately one-half cycle daily.Boston Edison checks their laboratory standards and works closely with Warren
401916: Warren introduces the Master Clock Type A Warren is given an opportunity to demonstrate his regulating instrument, intended to eliminate errors in frequencyOctober 23, 1916 Boston Edison puts the Warren Master Clock into OperationBy the Mid 1920’s Telechron clocks were in use by 20 million people
41The Warren “A” Type Master Clock is a Precision Regulator The Type “A” is an exceedingly accurate time-keeper, mounted in a floor standing case60-beat pendulum and a Graham “dead beat” type escapement and invar pendulumClock can be regulated to within one second per dayClock main-spring is continuously wound by synchronous motor
42Type A Master Clock combines Pendulum Regulator and Synchronous Clock
43Regulation of Pendulum Clock by Weights and Magnetic Pulse Weight Tray on Pendulum Allow Operator to Change Rate.Dials in Case allow Operator to add Pull/Push to Pendulum via Electro-Magnets in Clock Base.
44Although Initially There is a Lack of Interest in Warren’s Clocks By Warren Master Clocks have been installedBy 1947 Warren Master Clocks regulated over 95% of the electric lines in the United States.** From Electrifying Time by Jim Linz
45Warren Introduces the “B” Type aster in April and July 1920
46The Warren Type “B” is a Compact Wall Mounted Master Motor and Clock act on the same index hand through gearingThe motor tends to drive the hand in one direction, and the clock in the opposite directionIf the rate of the clock and motor are the same, the hand stays at restIf the motor is fast the hand moves in a clockwise direction
47Differences between the “A” and “B” “The Type “A” is recommended for use where the greatest accuracy and reliability are sought”“The Type “B” may be used in exactly the same manner and for the same purpose as the Type “A” it finds its principal use in smaller plants that are tied in with a large system”
48Warren “C” Master Frequency Regulator Designed in 1920Differential Reading on Middle DialUpper dial (with knob) allows adjusting of seconds of clocks on linesLower dial displays the time
52Weight 13 Hanging on endless belt Weight is lowered by pendulum clock
53Weight 13 Hanging on endless belt Weight is lowered by pendulum clockWeight is lifted by the synchronous motor left
54When the line frequency and the pendulum rates agree, weight remains stationary.
55When the line frequency and the pendulum rates agree, weight remains stationary. If rates disagree, the difference is registered on the the scale
56When the line frequency and the pendulum rates agree, weight remains stationary. If rates disagree, the difference is registered on the the scaleWhen weight is lifted by the synchronous motor, it closes the switch which reduces the speed of the generator.
57When the line frequency and the pendulum rates agree, weight remains stationary. If rates disagree, the difference is registered on the the scaleWhen weight is lifted by the synchronous motor, it closes the switch which reduces the speed of the generator.As the weight falls the switch is open, and generator speeds up.
58Henry Warren and the Introduction of Synchronous Timekeeping How did Warren revolutionize timekeeping in the USWhat obstacles did Warren overcome to accomplish his goalsHow does the synchronous self-starting AC motor workHow did Warren help power stations to maintain 60HzHow did Warren convince the power generating companies to adopt his technology
59Power GridThe U.S. and Canada (with the exception of Quebec and most of Texas) are tied together in a single large power grid.All generators are synchronized to an exact 60Hz standard using references calibrated to the NIST atomic clocks.Phase matching and power transfer between networks effected by phase-varying transformers (a leading phase pushes powers, a trailing phase pulls it).On average, though, the finite speed of light implies ~ 4000/ sec propagation delay between Nova Scotia and San Diego - more than the 16.7ms of a complete 60 Hz wavelength.
60Modern Electric Clocks A paper read at a meeting of the Clock Club held at the Old State House, Boston MA on February 6, 1937