US3876840A

US3876840A - Automatic time-temperature-message announcing system

Info

Publication number: US3876840A
Application number: US364529A
Authority: US
Inventors: Jr Ellis H Bryant
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-05-25
Filing date: 1973-05-25
Publication date: 1975-04-08
Anticipated expiration: 1992-04-08

Abstract

An announcing system in which the time, temperature, and commercial weather message announcements are provided on a single mechanism with one record and the TTA system will operate in any spatial orientation including a horizontal position. A stepping motor is used for a magnetic detent of the recording system and operates to positively position the magnetic sound heat in the center of a magnetic record track. Completely automatic time and temperature services are provided with no daily maintenance or initial time setting to maintain accuracy by utilization of the National Bureau of Standard''s WWV Radio broadcasts.

Description

' United States Patent Bryant, Jr.

Apr. s, 1975 1 1 AUTOMATIC TlME-TEMPERATURE-MESSAGE ANNOUNCING SYSTEM [76] Inventor:

N.W., Atlanta, Ga. 30327 [22] Filed:

May 25, 1973 Appl. No; 364,529

Ellis H. Bryant, Jr., 4881 Power Rd.

179/1002 MD, 6 C; 360/12 Primary E.\'aminerAlfred H. Eddleman Attorney, Agent, or FirmWatson, Cole, Grindle & Watson [57] ABSTRACT An announcing system in which the time, temperature. and commercial weather message announcements are provided on a single mechanism with one record and the TTA system will operate in any spatial orientation including a horizontal position. A stepping motor is used for a magnetic detent of the recording system and operates to positively position the magnetic sound heat in the center of a magnetic record [56] References Cit d track. Completely automatic time and temperature UNITED STATES PATENTS services are provided w1th no daily ma1g1tenance or m;

itial time setting to maintain accuracy y utilization o 3,632.880 1/1972 GOltlSChCln 179 1001 C 3.637.952 1 1972 Hw -6 et al. 179/1002 MD g 3 Bureau of s wwv Rad) 3,668,326 6/1972 Bryant, Jr 179/6 TA casts' 3.673.344 6 1972 Smith et 111.... 179/1001 C D 3,767,864 /1973 Smith et -.11. 179/1002 s Clams rawng F'gures =51 ENkBLE PULSE 197.0 FlZOM REMOTE 8111133111. 44 1 M\N.B\NM2Y A: ll- Ilikm SENS cooE CODE 1=1zoM BMW 29* SECOND 6 192011101 1111 TE\..D\G\TM. FROM BlNARY eMT 1=1e.1 WNUTE ENCODER 01v1oE1z 1111s DECODElZ T-\G1.1 110017. c1oc1 so 1.0 1

l 1511mm TEMP. LOGtC TEMnsEmALTo 56 51 secouos CLOCK c1oc1 PARALLEL s1111=T GMT ,9 SET zE1zo sET eEMERAToR REcnsTETL 4 '14 HR.'1\ME I 54 I l \TZJ 1 114 ONE PPM i TEMP i 9ml?! 3mm! M111. emmr sEeemnzY TEMP. 151mm CODE" T1ME PRESET mm 11k M0111T0R 1 10110012 1 101111011 Mo111To1z 116101116 68 68) QQJ 1 $7- \8,) LNCH 130 TEMR '14 1111 To 11 1111 11002 MmucE MlNUTE NWANCE 551m c0104 11/324 \NDEX LOG1C \NDEX LQGK EMBLE 1 J on 96 1 1 ,se 1214 12EMoTE E0002 M111. REMOTE $EC. REMoTE TEMP. \ZEMoTE REMOTE E0012 m) s0 94 E110112s111ET REG 10011. s1111=T REC-1 EQUlP. SHH'JREG. L0G11C c10c1 l i i g l X 102 TELEMNE 104ICODE HOLDlNG 14 [(0012 HOLDlNG [(0151: 110101116 ..cE11T1z11to11"-1cE 1 h MUM Gm u1Tc11 uncu 1811001 '7 f m r me No 1112.5TEP Mom M111.sTEP MoTov. sEc.sTEP MoTott TEMP. sTEP MOTOR LTELDlGflAL gum $EW MR SERVO AMP. SERVO NAP. SERVO NAP.

UNE DRNEK SlGNN- 0 TL} Q n a 4 no 86 1 8B E1- E11- E11- E11- To COMMERQAL cE1z 00m c00E1z co0E1z gems? mom/0161; mom/menu. ENE 11 300110 111111500110 u o p u TME/TEMP- 1 1=1zo111=1e4 MFlCu'l SEC 50 N 01113 PHONE UNE HEAD PATENTEUAPR 8l975 WU q F n 3 7 4 V CHANNEL F/, j

SELECTQR 'ME CODE E0 KHL "LE ANT) PTLTERE 'ZBMH'I SMHT. N) E ET NAL \0 MH'L 4 LEVEL NUNTTUR MHZ v1 TRTEEER EUSEAE '19 SW EERTAL BCD TTME cooE 7.7.1 T

ENABLE 3o EAT 5\-\\FT REeAsTER ':3 2 833% N GMT 66" EERTAL PUT To PARALLEL OUTPUT Eco HOUR L4 L ,n EAT PosmoN '5 mm. UT .44 DETECUON GMT Eco To NALBcU To \RTE-U MODW-VED Mpugg FOR 41 ETNARY ETNARY CODE CODE EURMAT V AMEQHMJEAL CONVERTER CONVERTER DETECTOR REGSTER 45 GMT BEAT NR. NTN. E EAT J BNMZY CODE BmARY (00E 6 ENABLE PULSE T H6 To H63 I SANDER \M\LL\"ECOND g /6. Z ENABLE PULEE '5"! 0UT5\UE \40 TU H RESTETANcE ERMOMETER sERvo PEEUEAER \S'E PREUETQN LUETc 54 PQTENTTUNETER GELOiROR ER RESBTANCE REF. coUE MEAsURmE {3 LoNvERTER URCLHT \eo L W1 j sATPT REETsTER TELEPNoNE :HVLTO FoR PARALLELTo UNE D\Z\\IE\Z w sER. coNvEREmN c\RcU\T H635 ERMOMETER SERVO 8 ETT PARALLEL ETNA Y CODE \Giia AMPUHER f) T TR\GGER moo TEMPERATURE \44 \51 GRAY coUE To LED ETNARY NoNmR I coNvERTER I POWER PAoTo Hes SUPPLY TRANSBTORS 'm HREAPAUT AUTUMATTQ SVOLT nv sToRAEE BATTERY WNW BATT 6% QNAREER vas H i; AFR 81925 1 C SF 1 G SHEET FROM HGA \ooe,

960 Hz [004- j \NPUT T0 HGJ'I Ga a Y r LEVEL sme WAVE FOR.

vcc R8 MARKET woue NV +14v 4 :1 \008 IL Aumo em 'lOOfuxd 15v PD J. FOR MAX. '5\NE WAVE OUTPUT AUTOMATIC TlME-TEMPERATURE-MESSAGE ANNOUNCING SYSTEM This invention relates to time-temperatureannouncing machines (TTA) of the type which will automatically announce the time. temperature. and a commercial message in response to a request made by dialing the central office of a telephone exchange system. Prior art TTA systems have required separate records for the time. temperature. and the commercial messages to be announced and have used gravity actuated magnetic sound head devices and mechanical detent bars for positioning the magnetic sound head at the respective recordings. Such TTA systems are mechanically complex. require a great deal of operator attention. and can be operated only in a horizontal position. thereby significantly limiting the scope of their applications.

The TTA system of this invention presents a significant improvement and advancement over prior art TTA systems and has the following advantages and features over such known systems. The time. temperature, and commercial weather message announcements are provided on a single mechanism with one record and the TTA system will operate in any spatial orientation including a horizontal position. Therefore. the system can be used in spacecraft or in aircraft. etc.

A stepping motor is used for the magnetic detent of the recording system and operates in conjunction with a production ball screw to positively position the magnetic sound head exactly in the center of a magnetic record track. thereby eliminating complex and difficultto-manufacture detent bars and mechanical linkage. A four magnetic head system enables the machine to be adapted for computer speech synthesis and to provide multiple outputs. Completely automatic time and temperature services are provided with no daily maintenance or initial time setting to maintain an accuracy of 5 milliseconds at all times by utilization of the National Bureau of Standards WWV Radio broadcasts.

Temperature update data is transmitted to the TTA system at a central location from a remote temperature sensor over a single pair of telephone wires. The accuracy is sufficient for official Weather Bureau temperature certification (plus or minus Vz F.) over a 161 temperature range with excellent long term calibration stability. Digital outputs are provided for use in commercial time-temperature outdoor advertising signs as well as inside premise displays. Binary data representing time. temperature are also braodcast over the telephone companys central office dial tone generator to all of its area subscribers for automatically setting digital clocks and other equipment operated from a digital input. This information is received automatically when a subscriber originates a telephone call.

Special circuit enables daylight savings time changes to be preset up to 24 hours in advance of the 2:00 AM. Sunday morning correction. therefore making it unnecessary for operating personnel to be present when the automatic change occurs.

Continuous variable cycle recordings are made by stepping the magnetic head from track to track in sequence thereby providing up to 21 minutes of recording time with no noticeable interruption as the machine steps from track to track.

The TTA system uses dual compliance flutter filters with the rotating masses and the main drive motor completely submerged in transmission oil to provide viscous damping. cooling and lubrication, thereby enabling production of gear driven announcement machines to be consistently constructed with wide band flutter of less than 0.05 percent.

Automatic weather announcements programmed by ESSA teletype circuits are transmitted with an address and specific forecast for the involved zone in any one of one thousand prerecorded announcement combinations. The local official temperature is included from the Weather Bureau office and after the weather update from ESSA the teletype circuit is seized and the local temperature derived from the local weather office is transmitted back to the Weather Bureau's regional office thereby providing confirmation that the system has actually been updated within any given zone. This provides a hands-off" automatic service for small communities that is broadcast over the community telephone system. Such a service and its coding arrangement has been described in ESSA Bulletin W- 1132. July 18, 1969.

Recordings of locally variable cycle weather announcements made by Weather Bureau personnel from their local office or other remote location. along with the official temperature. are provided over one line telephone circuit to the TTA equipment located in the telephone companys central office. The announcements are distributed over the weather network on a multiple entry demand basis and such a service has application for medium and large sized cities.

In large metropolitan areas. such as New York City where a message rate telephone service is used. the telephone company may lease the time network to distribute sports announcements. such as baseball. football. basketball scores.

An absolute linear encoder fabricated from a metal plate provides feedback as to the exact positioning of a sound head on a magnetic track. The encoder is coded in a special eight-bit gray code and when used for temperature indication provides a range of 99 to +l F. for a 256 eight-bit code. The encoder is positioned by a resistance bridge to provide an exact code output that corresponds with the temperature to an accuracy of plus or minus /2 F.

The TTA system is free from mechanical indexing disturbances caused by record rotation. A greater flexibility of the types of announcement services is provided by the fact that all timekeeping and other functions are external to the TTA mechanism itself. The carriage assemblies are completely modular and are interchangeable simply by unplugging and removing a few mounting screws.

An advance index system is provided whereby the TTA system will advance the hour and minute recordings 6 seconds before the new hour and minute so that the time announcement is completed at the start of the 960 Hz tone marker indicating exactly the beginning of a new hour. The system may also be programmed to advance the hour and minute index for commercial systems where the time is announced in one minute increments.

A synchronizing system is required to bring the prerecorded time announcing record into exact synchronization with the time and this is accomplished on startup of the TTA system by an optical interrupter switch which is mounted so that the record operates it once per revolution. An internal system counter set by the output of the interrupter switch and another counter is set once every minute by the radio corrected master clock. The outputs of these two counters are compared with each other to advance the main drive motor when the record is slow in relation to the actual time. or retard the main drive motor when the record is fast in relation to the actual time. The accuracy of the synchronizing system is plus or minus 2.4 milliseconds.

A message assembly announcement synthesizing unit provides a message hours. minutes. seconds and the temperature in sequence on any one of three-or more output channels. and central office line trunk control pulses as well. The output of the three or more channels is offset by 5 seconds. the outputs of each of the three channels are exactly the same except for their time relationship or change in temperature. The telephone central office trunks are switched at the next available announcement when a new call comes in by standard central office techniques to improve the quality of the service by limiting the waiting time to a maximum of 5 seconds to obtain access to an announcement. The average waiting time is 2 /2 seconds which provides the subscribers with a full and complete announcement even during heavy traffic periods.

OBJECTS OF THE INVENTION A primary object of the invention is to provide a more economical and less mechanically complex time. temperature. and message announcement system.

A further object of the invention is to provide a significant improvement in reliability and utility of such TTA systems.

A third object is to provide a TTA system which can be applied to computer speech synthesis configurations.

A fourth object of the invention is to provide a time. temperature. and message announcement system which is completely automatic and requires no operator attention.

A fifth object of the invention is to provide control outputs in a TTA system for operating outdoor or indoor advertisiing displays.

A sixth object is to provide a TTA system which may be broadcast over telephone company central office dial tone generator equipment to all area subscribers and which will automatically set digital clocks and other machinery.

A seventh object of the invention is to provide a TTA system that may be automatically set for Daylight Savings time changes.

An eighth object of the invention is to provide a TTA system having continuous variable cycle recordings which are made available by sequentially stepping a magnetic head from track-to-track.

A ninth object of the invention is to provide a TTA system having substantial improvement in flutter performance which is capable of being produced with a wide band flutter of less than 0.05 percent.

A tenth object of the invention is to provide automatic weather announcements selected from any one of a thousand prerecorded announcement combinations and which is programmed by ESSA teletype circuits.

An eleventh object of the invention is to provide a TTA system using an absolute linear encoder to provide feedback as to the exact position of a sound head with respect to a miltiple track recording system.

LII

A twelfth object of the invention is to provide a TTA machine in which all time-keeping. temperature, and weather functions are external to the machine itself, thereby reducing or eliminating mechanical indexing disturbances.

A thirteenth object of the invention is to provide a TTA system having modular carriage assemblies for improving the flexibility of the apparatus.

A fourteenth object of the invention is to provide an improved TTA system having an advance index system for completing announcements at the start of a 960 Hz tone marker at the beginning of each new minute and hour.

A fifteenth object of the invention is to provide a synchronizing system for synchronizing the prerecorded time announcing record with the exact time.

A final object of the invention is to provide a TTA machine having a message assembly announcement synthesizing unit for sequentially generating three or more output channels of messages comprising hours. minutes. seconds. temperature, and a weather/commercial announcement. wherein the average access time to an announcement is considerably reduced over prior art mechanisms.

GENERAL DESCRlPTlON The automatic time-temperature-annoueing TTA system receives a radio signal from WWV via a radio antenna located at the telephone company location. The entire TTA system operates from batteries and power is applied when the system is first made operational. The WWV signal is applied to a standard superheterodyne receiver tuned to the signal frequency. When a sufficient signal input is available. the audio output contains various information including a I00 Hz tone that is modulated with the digital time information. A Hz filter separates the one pulse per second. one frame per minute. information from the other data. This AC signal voltage is rectified and filtered and the fluctuating DC voltage is then applied to the input of a Schmitt trigger. The output of the Schmitt trigger represents the serial binary coded decimal (BCD) official time code that was transmitted originally from WWV. An enable signal is generated by application of a complete time frame of the interrange instrumentation group format H (lRlG-H) modified time code with the proper identification logic by means of a shift register. The lRlG-H time code has a 1 minute time frame and a 23-bit BCD code word with one minute resolution. The basic element rate is l pps. The code is defined in Document 104-70 published by Seeretariat. Range Commanders Council. White Sands Missile Range. New Mexico. 88002. The enable signal certifies that the time code is correct. complete and that the received binary coded decimal (BCD) Greenwich mean time (GMT) hour and minute are in the proper position in the shift register. The actual time of the operation of the enable circuitry is 29 seconds after the hour and minute stored in the shift register plus the propagation delay time from the WWV antenna to the output of the radio receiver at the telephone company.

The enable signal is applied to a local presettable clock. Simultaneously. the time is parallelly inserted from the GMT time stored in the shift register subsequent to its BCD-to-binary conversion. The second is generated locally at the 29th second in a minute. A divider chain between a free wheeling 3.9 MHz oscillator and a 1 Hz output is reset so that the next seconds pulse is corrected for the radio propagation delay. For example. a 3 millisecond delay indicates that the next output of the seconds pulse will be 997 milliseconds later. The logic reset delay is adjusted according to the receiver location in the above manner. The local binary block is thereby set to correct GMT time and will remain so as long as an occasional WWV reset is applied. The local free-wheeling oscillator has a drift rate of only five parts in 10" per day. In the event. for whatever reason. that the WWV signal is unavailable. the local GMT clock may be manually set. A mechanical counter is provided for recording the number of enable pulses per day.

The GMT binary hour is applied to adjustable logic circuitry for subtracting the GMT offset from the local 24 -hour time. For example. 19:31 GMT is equivalent to 14:31 Eastern Standard Time during the winter months when there is a 5 hour offset. During the summer months for daylight savings time 19:31 GMT is equivalent to 15:31 Eastern Standard Time. which represents a 4 hour offset. The normalization to local time is accomplished by operation of a key on the TTA equipment any time within the 24 hours preceding an actual time change. The correction is made automatically at 2:00 a.m. the following morning.

The binary 24-hour time is applied to the TTA hour step motor servo-amplifier and also to a remote equipment shift register. when a 24-hour local clock is desired. or for other special requirements.

The 24-hour local binary time is normally converted by suitable logic circuitry to 12-hour local time and applied to an hour step motor servo-amplifier having a Nixie readout that may be switched from GMT to 24- hour local time. another monitor position indicating the last-received data from WWV, or 12-hour local time. Nixie readouts are also provided for minute and second monitors.

The binary minute output from the presettable local clock is applied to a minute step motor servo-amplifier and a remote equipment shift register. The binary seconds output from the presettable clock is applied to'a temporary storage register which is enabled by the presettable clock every 5 or 10 seconds as may be required. The output of the temporary storage register is then applied to a seconds step motor servo-amplifier.

The binary step motor servo-amplifier consists of an 8-digit logic comparator that compares the incoming binary code with the .l-bit binary code derived from the 8-bit modified Gray code converter. The 8-bit modified Gray code is derived from a mechanical metal and coded plate and an LED/photo transistor optical encoder. The metal encoder plate is mounted on the step motor servo-carriage assembly. The step motor is stepped one step at a time at a rate of 60 steps per second in a direction controlled by the logic comparator. The step motor moves the encoder in one direction until the exact code is reached whenever the logic input is larger than the mechanical position of the encoder. However. if the mechanical position of the encoder is lower than the required input. the step motor moves the mechanical encoder in the opposite direction until the exact code is reached. An advantage of the step motor drive is that it is energized when it rests and will remain in the exact position until the input logic code is changed. Additionallyg the step motor will return to a given position in the event it is mechanically forced away and then released. Such apparatus represents an absolute encoder system whereby the exact carriage position is defined by the optical encoder and the binary input at all times.

A combination record. playback and erase magnetic head is mounted on the step motor carriage. The exact position of the magnetic head relative to the record is determined by a magnetic detent in the step motor, and adjustment of a ball lead screw nut mechanism, the position of the optical encoder and the input logic code. The ball screw and magnetic detent determine exact head position relative to a magnetic record track and the optical encoder determines which of 256 track positions the head is at for a given logic input. All step motor servo assemblies are alike and are modular and thereby interchangeable.

All time-keeping, temperature measuring, and variable message cycle links are generated by logic circuits and the data is converted into binary codes which the step motor servo-systems match with the proper recording track. The message assembly logic circuitry switches the magnetic head outputs to synthesize the required speech continuity and output. The message assembly unit also generates pulses for controlling the telephone central office common trunk equipment. for example. such as CO and CT pulses. The message assembly master timer is controlled by an optical interrupter switch associated with the record. thereby generating a pulse once per revolution. The message assembly unit blocks any servo changes during the time the track is announcing a message.

The remote equipment register is parallelly set by the local time and official temperature logic. A logic clock transmits a serial output once per second and that data operates a telephoneline driver for transmission of digital information to a sponsors remote location. Audio information is also transmitted over the same telephone wires on a time-sharing basis. The serial output is used at the sponsors premises for correct time and official temperature displays and. for example. electric outdoor advertising signs. The remote equipment shift register may also transmit digital information to a special telephone company dial tone generator to enable all subscribers within the telephone companys operating area to automatically set digital clocks on their premises. The digital time information may also be used internally by the telephone company in any number of applications.

The entire TTA system is adequately guarded by alarms for notifying telephone central office maintenance personnel in the event of a malfunction of the equipment. The alarm system also functions to make busy" subscriber trunk circuits.

Telephone trunk circuits previously used in TTA systems usually comprise a relay for indicating connection of an incoming call to a trunk. A holding relay is set to delay the connection of the audio and the "ring trip" of the central office equipment until the beginning of the next complete announcement cycle which is indicated by a CT pulse from the system. A CT relay is actuated for connecting the audio until the end of the announcement cycle and the CT relay is released by a CO pulse from the system to restore the trunk for the reception of a new telephone call. Such telephone trunk circuits have a number of disadvantages and the TTA system of this invention provides a new interface between the TTA system and the telephone central office

Claims

1. Time-temperature and message announcing apparatus, comprising: means for independently storing hour, minute, seconds, temperature and message data; means for selectively retrieving each of said hour, minute, seconds, temperature and message data; means for independently positioning each of said means for retrieving in selected portions of said hour, minute, seconds and temperature data, respectively; means for receiving hour, minute, and seconds update signals and including means for receiving coded radio signals accurately representing time, means for converting said coded radio signals into respective hour, minute, and seconds codes, logic means responsive to said hour, minute, and seconds codes for generating respective hour, minute, and seconds update signals; means for receiving temperature data from a location remote from said apparatus; and means controlling the position of said means for retrieving said hour, minute, and seconds data in response to said hour, minute, and seconds update signals and for controlling the position of said means for retrieving said temperature data in response to said temperature data signals.

2. Apparatus as in claim 1 further comprising means for automatically resetting said means for independently positioning to account for a change from standard time to daylight savings time and from daylight savings time to standard time.

3. Time-temperature and message announcing apparatus as in claim 1 wherein said means for independently storing hour, minute, seconds, temperature and message data is a single recording mechanism.

4. Time-temperature and message announcing apparatus as in claim 1 wherein said means for controlling operates automatically in response to said hour, minute and seconds update signals.

5. Apparatus as in claim 1 further comprising means for generating said temperature data and including means for measuring the temperature, a servo system rotated in accordance with the temperature measurement at said remote location and means for converting said measured temperature into binary coded signals, said means including an encoder wheel driven by said servo system and a number of light emitting diodes and a corresponding number of phototransistors aligned on respective sides of said encoder wheel, said encoder wheel including a modified Gray code having bits spaced to compensate for the non-linear readings from said means for measuring temperature.

6. Apparatus as in claim 5 wherein said temperature data is transmitted from said means for measuring the temperature via a pair of telephone lines.

7. Apparatus as in claim 1 wherein each of said means for independently positioning further includes encoder means for each of said means for retrieving and each said encoder means having an encoder plate, a set of light emitting diodes mounted on one side of said encoder plate and a set of corresponding phototransistors mounted on the opposite side of said encoder plate and aligned with said set of photodiodes, and means for receiving the signals from each of said set of phototransistors to generate a positioning signal.

8. Apparatus as in claim 7 wherein said means for selectively retrieving comprises separate modular carriage assemblies for said hour, minute, seconds and temperature data, each of said carriage module assemblies including a pair of spaced slide rods mounted between a pair of mounting plates, a threaded rod extending between said mounting plates and said slide rods, a ball and screw mechanism engaging with said threaded rod, a sound head carriage mounted to slide on said slide rod and engaging said ball and screw mechanism, a step motor for rotating said threaded rod and a positioning member comprising said encoder plate, said photodiodes and said phototransistors.

9. Apparatus as in claim 7 wherein each of said means for independently positioning further includes a step motor responsive to that positioning signal from a respective one of said hour, minute, seconds and temperature encoder means.

10. Apparatus as in claim 1 further comprising means for rotating said means for independently storing and including a rotatable drum having a recording surface; means for generating stable oscillation pulses for driving said means for rotating; means for generating period synchronization signals in accordance with the rotation of said drum; means for generating precise repetitive signals from said hour, minute, and seconds update signals; means for synchronizing the rotation of said drum with said hour, minute, and seconds update signals, means for comparing said repetitive signals and said stable oscillation pulses to determine whether the rotation of said drum is slow, fast or accurate, and programmable divider means responsive to said fast, slow or accurate comparison signals for adjusting the division of said stable repetitive oscillation signal; and means for generating pulses responsive to said programmable divider means to control said means for rotating.

11. Apparatus as in claim 10 wherein said means for generating periodic synchronization signals includes a second photodiode and a second phototransistor mounted in sapced aligned relationship with respect to one another and to the housing of said apparatus, a projection extending from said drum and positioned to rotate with said drum between said spaced photodiodes and phototransistors to periodically interrupt the light path therebetween with each revolution of said drum.

12. Apparatus as in claim 10 further comprising means for lubricating the surface of said drum.

13. Apparatus as in claim 10 wherein said means for rotating includes a central shaft supporting said drum, a motor for rotating said shaft, first and second flywheels, a first compliance filter member for mounting said first flywheel to said shaft, and a second compliance member for mounting said second flywheel to said shaft for maintaining the smooth rotation of said drum.

14. Apparatus as in claim 13 wherein said motor is submerged in a fluid to provide viscous damping, cooling and lubrication of said motor.

15. Apparatus as in claim 1 wherein said means for selectively retrieving includes at least three independent channels and further comprising means for generating voice synthesizing signals, and means responsive to said voice synthesizing signals for generating channel selection control signals whereby a different combined message including said hour, minute, seconds, temperature and message date is periodically generated.

16. Apparatus as in claim 15 wherein said means for selectively retrieving further includes means for automatically advancing said hour and minute data a predetermined interval prior to the announcement of each new hour and minute.

17. Apparatus as in claim 15 wherein said means for selectively retrieving includes hour, minute, seconds, temperature and message analog gates respectively controlled by said synthesis signals for generating voice signals respectively from said means for selectively retrieving.

18. Apparatus as in claim 17 wherein each of said analog gates includes a preamplifier and a means for gating the output of said preamplifier in accordance with said voice synthesizing signals.