US 20070286028A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2007/0286028 A1 Meltzer et al. (43) Pub. Date: Dec. 13, 2007

(54) RADIO Publication Classi?cation (76) Inventors.. David- Meltzer, Wappmger- Falls, ( 51) Int. Cl. NY (Us); Gregory Blum, G04C 11/02 (2006.01) Lagrangeville, NY (U S) (52) US. Cl...... 368/47 Correspondence Address: EPSON RESEARCH AND DEVELOPMENT INC (57) ABSTRACT INTELLECTUAL PROPERTY DEPT _ _ _ _ 2580 ORCHARD PARKWAY, SUITE 225 Apparatuses, circuits, and methods for rece1vmg at least one SAN JOSE, CA 95131 radio signal in a radio controlled timing apparatus using a single timing source. The present invention advantageously (21) App1_ NO; 11/423,101 eliminates the need to provide an additional timing source to receive at least one radio signal, and therefore reduces the ( 22 ) Filed; Jun, 8 , 2006 material cost and eliminates many eng ineerin g challeng es.

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RADIO WATCH coupled to a frequency divider 20 Which generates a real time signal 21. The real-time signal 21 is used to drive a FIELD OF THE INVENTION timing mechanism 30, and typically, has a frequency of one pulse per second. A broadcast time code [0001] The present invention generally relates to the ?eld signal 41 is received by an 42 and ampli?ed by an of radio controlled clocks. More speci?cally, embodiments RF ampli?er 43 to generate a modulated time code signal 44. of the present invention pertain to apparatuses, circuits, and The RF ampli?er 43 is coupled to a second quartz crystal 51 methods for receiving at least one radio signal in a radio to produce a time code signal 55. The resonance frequency controlled clock using a single reference timing source. of the second quartz crystal 51 is determined by the location and/or country in Which the radio controlled clock is speci DISCUSSION OF THE BACKGROUND ?ed to operate. For example, a unit marketed for operation [0002] A radio controlled clock is a timepiece capable of in the United States may have a second quartz crystal 51 adjusting its time by receiving and decoding a special time With a resonance frequency of 60 kHz. The time code signal code signal. The time code signal is encoded With the current 55 is received by a radio receiver/time code decoder 60 time and date and may also contain a daylight savings time Which generates a time setting and/or correction signal 61. and/or indicator. The time code signal may also The timing mechanism 30, by receiving the time setting contain parity bits for ensuring accurate reception. Typically, and/or correction signal 61, may therefore be synchronized this time code signal modulates a loW frequency carrier With the broadcast time code signal 41. signal Which is transmitted by a govemment-established [0006] More recent radio controlled clocks are marketed radio station. Several governments throughout the World for operation in multiple locations and/or countries and have established one or more radio stations to broadcast therefore are able to receive multiple broadcast time code such time code signals, including: the United States’ signals on different frequencies. FIG. 2 shoWs an example of WWVB broadcasting at 60 kHz; the United Kingdom’s hoW conventional multi-channel radio controlled clocks MSF broadcasting at 60 kHz; Germany’s DCF77 broadcast may differ from conventional single-channel radio con ing at 77.5 kHz; Japan’s JJY broadcasting at both 40 kHz trolled clocks. A loW frequency broadcast time code signal (transmitting in the Fukushima prefecture) and 60 kHz 141 is received by an antenna 142 and ampli?ed by an RF (transmitting on the border of the Saga prefecture and the ampli?er 143 Which generates a modulated time code signal Fukoka prefecture); China’s BPC broadcasting at 68.5 kHz; 144. A quartz crystal matrix 150 receives the modulated time SWitzerland’s HGB broadcasting at 75 kHz; and eastern code signal 144. The quartz crystal matrix may include Russia’s RTZ broadcasting at 50 kHz. Additionally, some quartz crystals 151, 152, 153 to convert the modulated time transmitters in the LORAN-C navigation system (Which code signal 144 into the time code signal 155. For example, broadcast at 100 kHz) transmit time code signals Which are a radio controlled clock marketed for operation in the United synchronized to Coordinated (UTC). Each States, Japan, and Germany may have one each of quartz of these radio stations modulates the carrier in substantially crystals With resonance frequencies of 60 kHz, 40 kHz, and the same manner: reduced carrier pulse Width modulation. 77.5 kHz. The sWitching matrix 154 determines Which of the HoWever, since different radio stations generally broadcast plurality of quartz crystals 151, 152, 153 are electrically time code signals on different frequencies, a radio controlled connected and is con?gured by a selectable frequency clock marketed for operation in more than one location control signal 170. HoWever, in some implementations, and/or country needs to be designed to receive time code quartz crystals 151, 152, 153 are all electrically connected signals on multiple frequencies. and thus the sWitching matrix 154 is not necessary. In such [0003] Broadcast time code signals are generated by an implementation, the radio controlled clock Will be used in modulating a carrier signal With a time code signal. Gener locations Where only one broadcast time code signal 141 is ally, the modulation is accomplished by the folloWing: a present, and thus, a valid time code signal 155 Will be carrier signal is locked to a precise oscillator (such as a generated by only one of the quartz crystals 151, 152, 153. cesium oscillator); a 60-bit time code containing at least the Similar to the conventional single channel radio controlled current time and date is generated With reference to a clock, the time code signal 155 is received by a radio national time source (such as UTC); and the carrier poWer is receiver/time code decoder 160 to produce a time setting dropped and restored at pre-determined times, depending on and/or correction signal 161. In addition to the multiple the modulated value of a speci?c time code bit. quartz crystals used in the quartz crystal matrix, the con [0004] Many radio controlled clocks contain one quartz ventional multi-channel radio controlled clock might also crystal for time keeping purposes and at least one additional have an additional quartz crystal to generate a real-time quartz crystal for demodulating the broadcast time code signal 21 as shoWn in FIG. 1. signal. The quartz crystal used for time keeping purposes is [0007] Quartz crystals are used in conventional radio time frequently divided to create a one pulse per second signal clocks because they have very stability. The Which drives a display mechanism. The frequency of the use of quartz crystals to generate a real-time signal leads to quartz crystal used for demodulating the broadcast time code timepieces Which keep very accurate time. The inherent signal correlates to the frequency of the particular radio stability of quartz crystals also increases the likelihood of station to be received. accurate demodulation of a broadcast time code signal, [0005] FIG. 1 shoWs an example of a conventional radio since, the carrier of the broadcast time code signal is locked controlled clock marketed for operation in a single location to that of a very stable cesium oscillator. HoWever, the and/or country. A ?rst quartz crystal 11 is coupled With an inclusion of multiple quartz crystals signi?cantly increases oscillator circuit 12 to provide a reference timing signal 13. the cost and size of such radio controlled clocks. A conven Typically, this ?rst quartz crystal 11 has a resonance fre tional quartz crystal radio controlled clock may contain up quency of 32768 Hz. The oscillator circuit 12 is further to N+l quartz crystals, Where N is the number of radio US 2007/0286028 A1 Dec. 13, 2007

frequencies that the quartz crystal radio controlled clock is [0015] The present invention advantageously provides an con?gured to receive. For example, a radio controlled clock economical approach to receiving at least one radio signal in Which is marketed for use in the United States, Japan, and a radio controlled clock using a single reference timing Germany may contain up to four quartz crystals. In addition source. Further, the present invention advantageously pro to the increased product cost, there are engineering and vides a novel implementation of a radio controlled clock manufacturing difficulties as Well: multiple quartz crystals Which is capable of receiving time code signals broadcast on need to ?t Within the device. Thus, using multiple quartz a plurality of frequencies. These and other advantages of the crystals in a radio controlled clock may be disadvantageous present invention Will become readily apparent from the because of increased material costs and engineering chal detailed description of preferred embodiments beloW. lenges. [0008] Therefore, a need exists for a radio controlled clock BRIEF DESCRIPTION OF THE DRAWINGS that can receive radio signals at any of a plurality of frequencies but Which enables the use of a single quartz [0016] FIG. 1 is a diagram shoWing a conventional single crystal. channel radio controlled clock Which uses one quartz crystal for demodulating a modulated time code signal. SUMMARY OF THE INVENTION [0017] FIG. 2 is a diagram shoWing a portion of a con ventional multiple-channel radio controlled clock Wherein [0009] Embodiments of the present invention relate to the single quartz crystal of FIG. 1 has been replaced by apparatuses, circuits, and methods for receiving at least one multiple quartz crystals to demodulate a modulated time radio signal in a radio controlled clock using a single code signal. reference timing source. [0018] FIG. 3 is a diagram shoWing a multiple-channel [0010] In one aspect, the invention concerns a radio con radio controlled clock of the present invention. trolled timing apparatus that can include: a radio receiver [0019] FIG. 4 is a diagram shoWing an implementation of con?gured to (i) receive a local carrier signal derived from a frequency synthesizer according to the present invention. a reference timing signal and at least one modulated time [0020] FIG. 5 is a diagram shoWing an implementation of code signal and (ii) generate a time code signal from the a radio receiver/time code decoder according to the present local carrier signal and at least one modulated time code invention. signal; a decoder con?gured to (i) receive the time code signal and (ii) generate a time setting and/or correction DETAILED DESCRIPTION OF THE signal therefrom; and a timing mechanism con?gured to PREFERRED EMBODIMENTS receive (i) a real-time signal derived from the reference timing signal and (ii) the time setting and/or correction [0021] Reference Will noW be made in detail to the pre signal. ferred embodiments of the invention, examples of Which are [0011] In another aspect, the invention concerns a circuit illustrated in the accompanying draWings. While the inven for a radio controlled timing apparatus that can include: a tion Will be described in conjunction With the preferred reference timing signal source; a frequency synthesizer embodiments, it Will be understood that they are not con?gured to (i) receive a reference timing signal and a intended to limit the invention to these embodiments. On the selectable frequency control signal and (ii) generate a local contrary, the invention is intended to cover alternatives, carrier signal from the reference timing signal and the modi?cations and equivalents that may be included Within selectable frequency control signal; the spirit and scope of the invention as de?ned by the [0012] a radio receiver con?gured to (i) receive the local appended claims. Furthermore, in the folloWing detailed carrier signal and at least one modulated time code signal description of the present invention, numerous speci?c and (ii) generate a time code signal from the local carrier details are set forth in order to provide a thorough under signal and at least one modulated time code signal; and a standing of the present invention. HoWever, it Will be readily decoder con?gured to (i) receive the time code signal and (ii) apparent to one skilled in the art that the present invention generate a time setting and/or correction signal therefrom. may be practiced Without these speci?c details. In other [0013] In yet another aspect, the invention concerns a instances, Well-knoWn methods, procedures, components, circuit for a radio controlled timing apparatus that can and circuits have not been described in detail so as not to include: a frequency synthesizer con?gured to (i) receive a unnecessarily obscure aspects of the present invention. reference timing signal and a selectable frequency control [0022] For convenience and simplicity, the terms “data,” signal and (ii) generate a local carrier signal from the “signal,” and “signals” may be used interchangeably, as may reference timing signal and the selectable frequency control the terms “connected to,” “coupled With,” “coupled to,” and signal; and a radio receiver con?gured to (i) receive the local “in communication Wit ” (Which terms also refer to direct carrier signal and at least one modulated time code signal and/or indirect relationships betWeen the connected, coupled and (ii) generate a time code signal from the local carrier and/or communication elements unless the context of the signal and at least one modulated time code signal. terrn’s use unambiguously indicates otherWise), but these [0014] In a further aspect, the invention concerns a terms are also generally given their art-recognized mean method of synchronizing a radio controlled timing apparatus ings. Also, for convenience and simplicity, the terms “com that can include: multiplying and/or dividing a reference puting,” “calculating,” “determining,” “processing,” timing signal by a ?rst ratio to generate a real-time signal; “manipulating,” “transforming,” “operating,” “displaying,” multiplying and/ or dividing the reference timing signal by a and “setting” (or the like) may be used interchangeably, and second ratio to generate a local carrier signal; generating a generally refer to the action and processes of a computer, time code signal from the local carrier signal and at least one data processing system, logic circuit or similar processing modulated time code signal; and decoding the time code device (e.g., an electrical, optical, or quantum computing or signal to generate a time setting and/or correction signal. processing device), that manipulates and transforms data US 2007/0286028 A1 Dec. 13, 2007

represented as physical (e.g., electronic) quantities. The at least one modulated time code signal; a decoder con?g terms refer to actions, operations and/or processes of the ured to (i) receive the time code signal and (ii) generate a processing devices that manipulate or transform physical time setting and/or correction signal therefrom; and a timing quantities Within the component(s) of a system or architec mechanism con?gured to receive (i) a real-time signal ture (e.g., registers, memories, other such information stor derived from the reference timing signal and (ii) the time age, transmission or display devices, etc.) into other data setting and/or correction signal. similarly represented as physical quantities Within other [0030] Referring noW to FIG. 3, a reference timing signal components of the same or a different system or architecture. source 210 generates a reference timing signal 213, 214. For [0023] The present invention concerns apparatuses, cir the purposes of this discussion, reference timing signal 213 cuits, and methods for receiving at least one radio signal in and reference timing signal 214 are typically the same a radio controlled timing apparatus With a single clock signal. HoWever, either or both of the reference timing source. In one aspect of the invention, the radio controlled signals may be adjusted, modi?ed, or otherWise differently timing apparatus can include: a radio receiver con?gured to processed With respect to the other (e.g., delayed, inverted, (i) receive a local carrier signal derived from a reference divided, and/or multiplied). Areal-time signal 221 is derived timing signal and at least one modulated time code signal from the reference timing signal 213. A local carrier signal and (ii) generate a time code signal from the local carrier 285 is derived from the reference timing signal 214. A radio signal and at least one modulated time code signal; a decoder receiver/time code decoder 260 receives a modulated time con?gured to (i) receive the time code signal and (ii) code signal 244 and the local carrier signal 285, and gen generate a time setting and/or correction signal therefrom; erates a time setting and/or correction signal 267 generally and a timing mechanism con?gured to receive (i) a real-time in response thereto. The time setting and/ or correction signal signal derived from the reference timing signal and (ii) the 267 and the real-time signal 221 are received by the timing time setting and/or correction signal. mechanism 230. Generally, the real-time signal 221 and the [0024] A further aspect of the invention concerns a circuit time setting and/or correction signal 267 are synchronized for a radio controlled timing apparatus that can include: a by conventional logic Within the timing mechanism 230. reference timing signal source; a frequency synthesizer HoWever, such synchronization may occur outside of the con?gured to (i) receive a reference timing signal and a timing mechanism 230 by using other conventional digital selectable frequency control signal and (ii) generate a local or analog methods that are Well knoWn to those skilled in the carrier signal from the reference timing signal and the art. selectable frequency control signal; a radio receiver con?g [0031] In one implementation, the radio controlled timing ured to (i) receive the local carrier signal and at least one apparatus may include a real-time signal generator 220 modulated time code signal and (ii) generate a time code Which receives the reference timing signal 213 and generates signal from the local carrier signal and at least one modu the real-time signal 221. The real-time signal generator 220 lated time code signal; and a decoder con?gured to (i) may include one or more multipliers and/ or dividers, and the receive the time code signal and (ii) generate a time setting con?guration of such real-time signal generators are Well and/or correction signal therefrom. knoWn to those skilled in the art. [0025] A further aspect of the invention concerns a circuit [0032] In a further implementation, the radio controlled for a radio controlled timing apparatus that can include: a timing apparatus may include a frequency synthesizer 280 frequency synthesizer con?gured to (i) receive a reference con?gured to receive the reference timing signal 214 and timing signal and a selectable frequency control signal and generate a local carrier signal 285. The frequency synthe (ii) generate a local carrier signal from the reference timing sizer 280 may include an integer or fractional-N (or “fractal signal and the selectable frequency control signal; and a N”, as it is sometimes knoWn) type phase locked loop and radio receiver con?gured to (i) receive the local carrier at least one divider. Frequency synthesizers comprising such signal and at least one modulated time code signal and (ii) a phase locked loop and a frequency divider are conven generate a time code signal from the local carrier signal and tional, and their design, implementation, and operation are at least one modulated time code signal. Well knoWn to those skilled in the art. An example of a [0026] A further aspect of the present invention concerns frequency synthesizer comprising an integer type phase a method of synchronizing a radio controlled timing appa locked loop and a frequency divider is shoWn in FIG. 4. ratus that can include: multiplying and/or dividing a refer [0033] Referring to FIG. 4, a reference timing signal 314 ence timing signal by a ?rst ratio to generate a real-time is divided by a ?rst frequency divider 381. A phase and/or signal; multiplying and/or dividing the reference timing frequency detector 382 receives both the divided reference signal by a second ratio to generate a local carrier signal; timing signal from a frequency divider 381 and a feedback generating a time code signal from the local carrier signal signal 389. The phase and/or frequency detector 382 is and at least one modulated time code signal; and decoding coupled to a loop ?lter 383 Which is further coupled to a the time code signal to generate a time setting and/or voltage controlled oscillator 384. The phase and/or fre correction signal. quency detector 382, loop ?lter 383, and voltage controlled [0027] The invention, in its various aspects, Will be oscillator 384 are conventional, and their design, implemen explained in greater detail beloW With regard to exemplary tation, and operation are Well knoWn to those skilled in the embodiments. art. For example, phase and/or frequency detector 382 may [0028] An Exemplary Radio Controlled Timing Apparatus comprise a conventional Type I Phase Detector Which [0029] In one embodiment, an exemplary radio controlled responds to the phase difference betWeen tWo input signals. timing apparatus includes: a radio receiver con?gured to (i) In the simplest form, the Type I Phase Detector may function receive a local carrier signal derived from a reference timing as a digital “exclusive-or” gate. Alternatively, the phase signal and at least one modulated time code signal and (ii) and/or frequency detector 382 may comprise a conventional generate a time code signal from the local carrier signal and Type II Phase-Frequency detector Which responds to the US 2007/0286028 A1 Dec. 13, 2007

timing difference between transition edges (i.e., rising edge [0036] Furthermore, the implementation and con?guration or falling edge) of tWo input signals. The voltage controlled of frequency dividers 381, 387, 388 as shoWn in FIG. 4 oscillator 384 is coupled to a frequency divider 387 to generally depends on the frequency of both the reference generate the local carrier signal 285. Additionally, the volt timing signal 314 and the local carrier signal 285 to be age controlled oscillator 384 is coupled to a frequency generated. For example, consider a radio controlled timing divider 388 Which generates a phase locked loop feedback apparatus con?gured to receive a broadcast radio time signal signal 389. The feedback signal 389 of the phase locked loop on the United State’s WWVB Which broadcasts at 60 kHZ. is received by the phase and/or frequency detector 382. If the radio controlled timing apparatus has a direct conver [0034] The divider ratios Within the frequency dividers sion receiver, a local carrier signal 285 With a frequency of 60 kHZ should be generated. Also, consider the same radio 381, 387, 388 are controlled by the status of a selectable frequency control signal 370. The selectable frequency controlled timing apparatus Where the reference timing signal 314 has a frequency of 32768 HZ. In one exemplary control signal 370 may be a digital multi-bit signal of n bits, implementation, frequency divider 381 may be con?gured Where 2” is the number of con?gurable states of the fre With a ratio of 1024, frequency divider 387 may be con?g quency synthesiZer (e.g., the number of possible local carrier ured With a ratio of 3, and frequency divider 388 may be frequencies to be produced). The number of con?gurable con?gured With a ratio of 5625. The phase and/or frequency states of the frequency synthesiZer may directly relate to the detector 382 therefore Will compare the reference timing number of broadcast time code signal frequencies that the signal 314 (frequency of 32768 HZ) divided by 1024 and the radio controlled timing apparatus is con?gured to receive. voltage controlled oscillator output signal 386 (frequency of The selectable frequency control signal 370 is decoded by 180 kHZ) divided by 5625. As is shoWn, the phase and/or control signal logic 371 to produce control signals P 372, Q frequency detector 382 should be capable of operating at 373, and R 374 Which determine the divider ratios of the frequencies beloW 3 kHZ (e.g., the comparison frequency is respective frequency dividers 381, 387, 388. Each control 32 HZ in the above example). HoWever, Where the frequency signal P, Q, or R may also be a digital multi-bit signal. For synthesiZer comprises a fractional-N type phase locked loop, example, if the frequency divider 381 requires 8 con?g the comparison frequency could be equal to the frequency of urable states, P may be a three-bit signal. The exemplary the reference timing signal 314 (and thus, frequency divider frequency synthesiZer is thus programmable and can gener 381 may be omitted). ate one or more local carrier signals With the same or [0037] In yet another implementation, the radio controlled different frequencies. Also, a single local carrier signal (e.g., timing apparatus as shoWn in FIG. 3 may include at least one 285) can have one of a plurality of frequencies. antenna 242 and/or at least one RF ampli?er 243 to receive [0035] In one implementation, and referring back to FIG. and/or amplify at least one broadcast time code signal 241. 3, each state of the selectable frequency control signal 270 Although the broadcast time code signals are generally in may correlate to a particular broadcast radio time signal to the loW frequency spectrum (betWeen 30 kHZ to 300 kHZ), be received [e.g., WWVB (broadcasting at 60 kHZ) corre typically, broadcast time code signals have frequencies of: lates to state one of the selectable frequency control signal, 40 kHZ (for transmissions from Japan); 50 kHZ (for trans DCF77 (broadcasting at 77.5 kHZ) correlates to state tWo of missions in eastern Russia); 60 kHZ (for transmissions from the selectable frequency control signal, JJY (broadcasting at both the United States and Japan); 68.5 kHZ (for transmis 40 kHZ) correlates to state three of the selectable frequency sions from China); 75 kHZ (for transmissions from SWitZer control signal, JJY (broadcasting at 60 kHZ) correlates to land); and 77.5 kHZ (for transmissions from Germany). In a state one or state four of the selectable frequency control typical implementation, the loW frequency broadcast time signal, and MSF (broadcasting at 60 kHZ) correlates to state code signal 241 is received by the antenna 242 and ampli?ed one or ?ve of the selectable frequency control signal.] In by the RF ampli?er 243. The output of the RF ampli?er 243 another implementation, each state of the selectable fre is a modulated time code signal 244. quency control signal 270 may correlate to differential [0038] The radio receiver/time code decoder 260 may values for the purpose of frequency scanning (e.g., “up 17.5 consist of separate functional elements. As shoWn in FIG. 5, kHZ” correlates to state one of the selectable frequency the local carrier signal 285 and the modulated time code control signal, “doWn 17.5 kHZ” correlates to state tWo of signal 244 are inputs to the radio receiver 461. The radio the selectable frequency control signal; “doWn 20 kHZ” receiver 461 may consist of a mixer 463 and a signal correlates to state three of the selectable frequency control conditioner 464. The output of the radio receiver 461 is a signal, and “up 20 kHZ” correlates to state four of the time code signal 466 Which is received by a time code selectable frequency control signal). The selectable fre decoder 462. Typically, the time code signal 466 contains at quency control signal 270 may be con?gured by a simple least the current time, hoWever the time code signal 466 may user interface device, such as an external sWitch or button. also contain: the date; daylight savings time and leap year Alternatively, the selectable frequency control signal 270 indicators; parity information; and/or other information. In may be con?gured Within the radio controlled timing appa one implementation, the time code decoder 462 is contained ratus. In one implementation, the selectable frequency con Within a microprocessor. In an alternative implementation, trol signal 270 can be derived by the radio receiver/time the time code decoder 462 is contained Within a logic array code decoder 260. For example, the radio receiver/time code element (such as a programmable logic device or ?eld decoder 260 may contain logic Which determines the pres programmable gate array) or an application speci?c inte ence of a valid broadcast time code signal 241. The radio grated circuit. The time code decoder 462 generates the time receiver/time code decoder 260 may further contain logic setting and/or correction signal 267. As discussed above and Which may be con?gured to sequentially select each state of as shoWn in FIG. 3, the time setting and/or correction signal the selectable frequency control signal 270 until a valid 267 and the real-time signal 221 may be synchroniZed broadcast time code signal 241 is present. Within the timing mechanism 230. US 2007/0286028 A1 Dec. 13, 2007

[0039] An Exemplary Circuit for a Radio Controlled Tim be of the super-heterodyne type. Super-heterodyne radio ing Apparatus receivers combine a broadcast carrier signal modulated With [0040] In another embodiment, a circuit for a radio con a baseband signal and a local carrier signal Whose frequency trolled timing apparatus can include: a reference timing is equal to the broadcast carrier signal plus or minus a ?xed signal source; a frequency synthesizer con?gured to (i) offset (ie the intermediate frequency). Generally, the inter receive a reference timing signal and a selectable frequency mediate frequency is less than the local carrier frequency. control signal and (ii) generate a local carrier signal from the The output of the mixer is then ?ltered to remove the reference timing signal and the selectable frequency control undesired modulation products. The resulting signal is the signal; a radio receiver con?gured to (i) receive the local modulating baseband signal. Thus, Where the radio receiver carrier signal and at least one modulated time code signal 461 is of the super-heterodyne type, the local carrier signal and (ii) generate a time code signal from the local carrier 285 Will have a frequency equal to that of the desired signal and at least one modulated time code signal; and a broadcast time code signal 241 plus the ?xed intermediate decoder con?gured to (i) receive the time code signal and (ii) frequency. For example, a circuit for a radio controlled generate a time setting and/or correction signal therefrom. timing apparatus Which contains a super-heterodyne receiver [0041] Referring noW to FIG. 3, a reference timing signal With an intermediate frequency of 4.5 kHz generates a local source 210 generates a reference timing signal 213, 214. In carrier frequency of 82 kHz to receive the German broadcast one implementation, the reference timing signal source 210 time code signal (77.5 kHz plus 4.5 kHz). may include a quartz crystal 211 and an oscillator circuit [0044] In another implementation, the radio controlled 212. The quartz crystal 211 may further have a resonance timing apparatus may include a real-time signal generator. frequency of about 2X Hz, Where X may be an integer of Referring back to FIG. 3, the real-time signal generator 220 from 10 to 20 (e.g., l4§X§ 18). In one implementation, the receives the reference timing signal 213 and generates the crystal has a frequency of about 32768 Hz (i.e., X equals 15). Reference timing signal 213 and reference timing signal real-time signal 221. The real-time signal generator 220 may include of one or more multipliers and/or dividers, and the 214 may be the same or different, as discussed above. A frequency synthesizer 280 receives the reference timing con?guration of such real-time signal generators are Well knoWn to those skilled in the art. Where the reference timing signal 214 and a selectable frequency control signal 270 and signal source 210 comprises or consists of a quartz crystal generates a local carrier signal 285. A radio receiver/time 211 With a resonance frequency of 32768 Hz, the real-time code decoder 260 receives the local carrier signal 285 and a signal generator 220 may comprise or consist of a binary modulated time code signal 244 and generates a time setting divider. Typically, the real-time signal 221 is used to drive and/or correction signal. The radio receiver/time code the timing mechanism and has a frequency of one pulse per decoder 260 may include of separate elements as described second. above and shoWn in FIG. 5: a radio receiver 461 and a time code decoder 462. [0045] In a further implementation, the frequency synthe [0042] In yet another implementation, and as shoWn in sizer 280 may include an integer or fractional-N type phase locked loop and at least one divider. Frequency synthesizers FIG. 3, the radio controlled timing apparatus may include at least one antenna 242 and/or at least one RF ampli?er 243 comprising such a phase locked loop and frequency divider to receive and/or amplify at least one broadcast time code are conventional, and their design, implementation, and signal 241. Although the broadcast signals are generally in operation are Well knoWn to those skilled in the art. An example of a frequency synthesizer comprising an integer the loW frequency spectrum (betWeen 30 kHz to 300 kHz), typically, broadcast time code signals have frequencies of: type phase locked loop and a frequency divider is shoWn in 40 kHz (for transmissions from Japan); 50 kHz (for trans FIG. 4 and is discussed above. missions from eastern Russia); 60 kHz (for transmissions [0046] Another Exemplary Circuit for a Radio Controlled from both the United States and Japan); 68.5 kHz (for Timing Apparatus transmissions from China); 75 kHz (for transmissions from [0047] In yet another embodiment, a circuit for a radio Switzerland); and 77.5 kHz (for transmissions from Ger controlled timing apparatus that can include: a frequency many). In a typical implementation, the loW frequency synthesizer con?gured to (i) receive a reference timing broadcast time code signal 241 is received by the antenna signal and a selectable frequency control signal and (ii) 242 and ampli?ed by the RF ampli?er 243 as described generate a local carrier signal from the reference timing above. signal and the selectable frequency control signal; and a [0043] In a further implementation, and referring back radio receiver con?gured to (i) receive the local carrier noW to FIG. 5, the radio receiver 461 may be of the direct signal and at least one modulated time code signal and (ii) conversion type. When a broadcast carrier signal modulated generate a time code signal from the local carrier signal and With a baseband signal is mixed With a local carrier signal at least one modulated time code signal. Whose frequency is equal to the broadcast carrier signal, as [0048] Referring noW to FIG. 3, a frequency synthesizer in the case of direct conversion radio receivers, the signal 280 receives a reference timing signal 214 and a selectable that results is the modulating baseband signal. Thus, Where frequency control signal 270 and generates a local carrier the radio receiver 461 is of the direct conversion type, the signal 285. The local carrier signal 285 and the modulated local carrier signal 285 Will have a frequency equal to that time code signal 244, may be received by a radio receiver of the desired broadcast time code signal 241. For example, (such as receiver 461 as shoWn in FIG. 5), Which may a circuit for a radio controlled timing apparatus Which include of a mixer 463 and a signal conditioner 464, and contains a direct conversion radio receiver generates a local Which may generate the time code signal 466. In one carrier frequency of 77.5 kHz to receive the German broad implementation, the circuit contains a time code decoder cast time code signal. In an alternative implementation, and 462 Which receives the time code signal and generates a time for improved receiver selectivity, the radio receiver 461 may setting and/or correction signal 267. US 2007/0286028 A1 Dec. 13, 2007

[0049] In another implementation, the circuit may include the selectable frequency control signal corresponding to at least one RF ampli?er to amplify at least one broadcast each broadcast radio station that to be received. time code signal. As discussed above and shoWn in FIG. 5, an RF ampli?er 243 may be coupled to an antenna 241 and CONCLUSION/ SUMMARY a radio receiver 461 for the purposes of amplifying a [0056] Thus, the present invention provides apparatuses, broadcast time code signal 241. The RF ampli?er 243 circuits, and methods Which can enable a radio controlled outputs a modulated time code signal 244. clock to receive radio signals at any of a plurality of frequencies using a single quartZ crystal. [0050] In yet another implementation, the circuit may [0057] The foregoing descriptions of speci?c embodi include a reference timing signal source. As shoWn in FIG. ments of the present invention have been presented for 3, the reference timing signal source 210 may be coupled purposes of illustration and description. They are not both to the frequency synthesiZer 280 and to the real-time intended to be exhaustive or to limit the invention to the signal generator 220, and provide a reference timing signal precise forms disclosed, and obviously many modi?cations 213, 214 thereto. In a further implementation, reference and variations are possible in light of the above teaching. timing signal source 210 may be a crystal oscillator. The embodiments Were chosen and described in order to [0051] An Exemplary Method of Synchronizing a Radio best explain the principles of the invention and its practical Controlled Timing Apparatus application, to thereby enable others skilled in the art to best utiliZe the invention and various embodiments With various [0052] In a further embodiment, a method of synchroniz modi?cations as are suited to the particular use contem ing a radio controlled timing apparatus can include: multi plated. It is intended that the scope of the invention be plying and/or dividing a reference timing signal by a ?rst de?ned by the Claims appended hereto and their equiva ratio to generate a real-time signal; multiplying and/or lents. dividing the reference timing signal by a second ratio to What is claimed is: generate a local carrier signal; generating a time code signal 1. A radio controlled timing apparatus comprising: from the local carrier signal and at least one modulated time a) a radio receiver con?gured to (i) receive a local carrier code signal; and decoding the time code signal to generate signal derived from a reference timing signal and at least one modulated time code signal and (ii) generate a time setting and/or correction signal. Typically, the time a time code signal from said local carrier signal and code signal contains at least the current time, hoWever the said at least one modulated time code signal; time code signal may also contain: the date; daylight savings b) a decoder con?gured to (i) receive said time code signal time and leap year indicators; parity information; and/or and (ii) generate a time setting and/ or correction signal other information. therefrom; and [0053] In one implementation, the method of generating a c) a timing mechanism con?gured to receive (i) a real time code signal may include: receiving a modulated time time signal derived from said reference timing signal code signal; and, demodulating the modulated time code and (ii) said time setting and/or correction signal. signal With the local carrier. In another implementation, the 2. The apparatus of claim 1, further comprising a real-time signal generator con?gured to (i) receive said reference method may also include adjusting the real-time signal in timing signal and (ii) generate said real-time signal there accordance With the time setting and/or correction signal so from. as to synchroniZe the radio controlled timing apparatus With 3. The apparatus of claim 2, Wherein said real-time signal a broadcast time code signal. generator further comprises at least one divider con?gured [0054] In yet another implementation, the method may to generate said real-time signal. also include displaying a representation of the real-time 4. The apparatus of claim 1, further comprising a fre signal. The representation may be displayed in a traditional quency synthesiZer con?gured to (i) receive said reference analog form (movable time hands) or in a digital display timing signal and (ii) generate said local carrier signal element, such as a liquid crystal display (LCD). therefrom. [0055] The frequency of the generated local carrier signal 5. The apparatus of claim 4, Wherein said frequency may correspond to the state of a selectable frequency control synthesiZer further comprises: signal. The state of the selectable frequency control signal a) a phase locked loop; and b) at least one divider. may be selected by a simple user interface, such as an 6. The apparatus of claim 5, Wherein said divider has a external sWitch or button. Alternatively, the selectable fre ratio determined by a frequency control signal. quency control signal may be con?gured Within the radio 7. The apparatus of claim 1, further comprising at least controlled timing apparatus by a logic element. One method one antenna and/or at least one ampli?er con?gured to of con?guring the selectable frequency control signal Within receive and/ or amplify said at least one modulated time code the logic element may include the steps of: selecting a ?rst signal. state of the selectable frequency control signal correspond 8. The apparatus of claim 1, Wherein said modulated time ing to a ?rst desired broadcast radio station; determining code signal has a frequency of from about 40 kHZ to about Whether a valid time code signal Was received; and if a valid 77.5 kHz. time code signal Was not received, selecting a second state 9. The apparatus of claim 1, Wherein said time code signal of the selectable frequency control signal Which corresponds is encoded With at least the current time. to a second desired broadcast radio station and likeWise 10. The apparatus of claim 1, Wherein said decoder is determining Whether a valid time code signal Was received. contained Within a microprocessor, a logic array element, or The process may repeat, sequentially, selecting each state of an application speci?c integrated circuit. US 2007/0286028 A1 Dec. 13, 2007

11. The apparatus of claim 1, wherein said timing mecha 15. The circuit of claim 12, further comprising at least one nism is con?gured to synchronize said real-time signal and ampli?er con?gured to amplify said at least one modulated said time setting and/or correction signal. time code signal. 12. A circuit for a radio controlled timing apparatus circuit 16. The circuit of claim 12, further comprising a real-time comprising: signal generator con?gured to (i) receive said reference a) a frequency synthesizer con?gured to (i) receive a timing signal and (ii) generate a real-time signal therefrom. reference timing signal and a selectable frequency 17. The circuit of claim 16, Wherein said real-time signal control signal and (ii) generate a local carrier signal generator further comprises at least one divider con?gured from said reference timing signal and said selectable to generate said real-time signal. frequency control signal; and 18. The circuit of claim 12, further comprising at least one antenna and/or at least one ampli?er con?gured to receive b) a radio receiver con?gured to (i) receive said local and/or amplify said at least one modulated time code signal. carrier signal and said at least one modulated time code 19. The circuit of claim 12, Wherein said frequency signal and (ii) generate a time code signal from said synthesiZer further comprises: local carrier signal said at least one modulated time code signal. a) a phase locked loop; and b) at least one divider. 13. The circuit of claim 12, further comprising a reference 20. The circuit of claim 12, Wherein said modulated time timing signal source. code signal has a frequency of from about 40 kHZ to about 14. The circuit of claim 12, further comprising a decoder 100 kHz. con?gured to (i) receive said time code signal and (ii) generate a time setting and/or correction signal therefrom.