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`
`US005095308A
`'
`5,095,308
`[11] Patent Number:
`Ulllted States Patent
`Hewitt
`[45] Date of Patent: Mar. 10, 1992
`
`
`[19]
`
`[54] TRANSCEIVER WITH BATTERY SAVER
`AND METHOD 0]: USING SAME
`
`[75]
`
`Inventor: Robert M. Hewitt. Fort Lauderdale.
`Fla.
`
`
`4.544.910 10/1985 Hoberman
`.................... 340/333
`
`4.547.770 10/1985 Suzuki et al.
`..... 340/636
`
`4.660.027
`4/1987 Davis .......
`.340/636
`
`..... 455/343
`4.679.224
`7/1987 Kawasaki er al.
`4,755,816 7/1988 DeLuca ........................ 340/823544
`
`[73] Assignee:
`
`Southern Marine Research, Inc,
`Miami. Fla.
`
`Primary Examiner—Donald J. Yusko
`Assistant Examiner—Michael Horabik
`
`[21] App1.No.: 462,715
`[22] Filed:
`Jan. 9, 1990
`H04B U“!
`[51]
`Int Cl ,
`[52] u.s'. ci. IIIIIfffffifI:.'.'.'ff.'.'.'-.'I.‘f"316/5345 340/636'
`455/343; 324/433
`[58] Field of Search ................... 34o/szs.44, 636. 661;
`455/343; 324/433
`
`[56]
`
`References Cited
`US. PATENT DOCUMENTS
`3.769.593 10/1973 Williams ......................... 340/825.“
`
`340/636
`3,877,001
`4/1975 Bogut ct al.
`,.
`
`4,244,050
`1/ 1981 Weber et al.
`.
`371/66
`8/1982 Collins ......
`4.342.953
`----- 320/13
`
`4.365.241 12/1982 Morishita .
`
`" 340/636
`4.493.001 11/1985 Sheldrake .
`
`""" 321g;
`4.509.102 4/1985 Ayer .............
`
`..... 455/73
`4/1985 Sekigawa a 3L
`4.509.201
`
`
`5/1985 Kinney .................... 324/433
`4.517.517
`6/1985 Mori ............................... 340/825.“
`4,523,332
`
`ABSTRACT
`[57]
`A portable transceiver has a battery saving feature
`which includesatimer, circuit which automatically cuts
`Off the Power supply 10 the receiver and “ansmit‘er for
`relatively long intervals and periodically turns on the
`Power suvply for relatively short intevals to check for
`transmission or receiver signals. If such signals are de-
`tected, the power supply continues to supply powers to
`the receiver and transmitter for the duration of the
`signals and for a short period thereafter. The trans-
`“1"" 315° ineludes a ban” “Rage delec'iofi Circui‘
`which will cut off the battery power supply if the bat-
`tery has discharge to a predetermined level . and which
`can be overridden in any emergency. The power supply
`is conveniently controlled by a pass device which must
`receive “operate“ signals from both the timer circuit
`.
`.
`.
`and the battery voltage detection Circuit.
`
`19 Claims. 3 Drawing Sheets
`
`PX 1031
`
`EXHIBIT
`Petitioner - Kyocera
`
`Kyocera PX 1031__1
`
`

`

`US. Patent
`
`Mar. 10, 1992
`
`Sheet 1 of 3
`
`5,095,308
`
`TURN ON
`RADIO
`
`50
`
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`
`‘l::’ 54
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`55
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`APPROACH
`LOW BATT.
`LED DRIVER
`
`BATTERY‘
`
`56
`
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`
`RC
`
`5/
`
`2/
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`I
`B
`
`TEST
`BATTERY
`HmH/LON
`
`A
`
`AND
`GATE
`
`
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`
`PASS
`DEVICE
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`X
`
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`MTR
`J_.L
`36
`
`
`BATTERY—
`CUTOFF
` OVERRIDE
`
`.
`
`38
`
`39
`
`SQUELCH
`RATE
`
`AUDIO
`AMP
`
`Loam
`INVERTER
`
`4,
`
`.
`
`l0 SECOND
`TIMER
`
`J K
`FLIP-FLOP
`I/O
`0/1
`
`4‘2
`
`45
`
`46
`47
`
`SLEEP
`TIMER
`
`Kyocera PX 1031_2
`
`Kyocera PX 1031_2
`
`

`

`US. Patent
`
`Mar. 10, 1992
`
`Sheet 2 of 3
`
`5,095,308
`
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`Kyocera PX 1031_3
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`Kyocera PX 1031_3
`
`

`

`US. Patent
`
`Mar. 10, 1992
`
`Sheet 3 of 3
`
`5,095,308
`
`
`
`m.mfix
`
`Kyocera PX 1031_4
`
`Kyocera PX 1031_4
`
`

`

`1
`
`5,095,308
`
`TRANSCEIVER WITH BATTERY SAVER AND
`METHOD OF USING SAME
`
`BACKGROUND OF THE INVENTION
`
`invention relates to transceivers and,
`The present
`more particularly, to battery powered transceivers with
`battery monitoring circuits.
`As used herein, “transceiver” includes radiotele-
`phones and cordless telephones.
`The increasing use of rechargeable batteries in elec—
`tronic and electromechanical equipment has stimulated
`the development of methods of preventing such batter-
`ies from being excessively discharged. The importance
`of this precaution stems from a number of factors re-
`lated to battery life and rechargeability. The major
`factors are the irreversible, deleterious changes that
`take place within most batteries when they are deeply
`discharged, changes which not only prevent the battery
`from being subsequently recharged to its full ampere-
`hour capacity, but also eventually lead to battery failure
`as a result of repeated deep discharges.
`An additional factor is the increasingly steep decline
`in battery voltage and the sharp rise in internal battery
`resistance as a battery approaches a condition of deep
`discharge. This resistance becomes an increasing por-
`tion of the dissipative, parasitic load, and a battery so
`abused rapidly loses its ability to maintain its terminal
`voltage under even a modest load. A further factor is
`the disproportionate lengthening of the time required
`for recharge of such batteries; relatively brief periods of
`use when the battery is approaching a deeply dis-
`charged condition may add hours to the time needed for
`recharge. Unfortunately, a battery which cannot be
`recharged overnight, and which requires up to 24 hours
`to recharge, will seldom be kept charging for the period
`necessary to obtain a full charge. More often, the bat-
`tery will be removed from the charger and will be put
`into service though only partially recharged, and this
`can result in a memory factor limiting the amount of
`charge which the battery will subsequently take.
`A variety of methods have been devised to monitor
`the terminal voltage of rechargeable batteries in order
`to sense when they are approaching deep discharge,
`and. along with control circuitry, to limit battery drain
`or even completely disconnect the load from the battery
`whenever the monitored voltage is sensed to have fallen
`below a desired threshold voltage.
`The focus of most of these methods is an economic
`concern to prevent the battery from being damaged to
`the point where recharge is impossible and the battery
`must be replaced. In some instances, another concern is
`to minimize the inconvenience of an interruption in
`service. The prior art has not recognized the impact of
`inability to make use of equipment under circumstances
`when the failed or deeply discharged battery imperils
`the safety or even the survival of the user and others.
`Such circumstances are frequently encountered in
`marine, police and fire applications. On small craft oper-
`ating offshore, the only means of communication may
`be a hand-held radiotelephone or transceiver operating
`on a rechargeable battery. Radiotelephones used on
`such small craft serve several vital functions aside from
`that of ordinary communication, one of the major func-
`tions being to monitor the Coast Guard emergency
`channel (VHF Channel 16), since it is on that channel
`that safety messages, small-craft warnings and distress
`calls are broadcast, as well as initial hailing calls are
`
`'1!
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`lo
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`25
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`30
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`2
`received. Another major function is to permit the trans-
`. mission of requests for emergency assistance on that
`channel, since it is monitored by the Coast Guard as
`well as by other craft which may be nearby and able to
`assist.
`
`The rapidity of weather changes offshore is well
`known; the transition of the weather from light breezes
`to a dangerous, if short-lived squall, may occur within a
`period of half an hour or less. Therefore, small craft
`operators typically keep their radiotelephone receivers
`on and tuned to the emergency channel to hear any
`small-craft warnings, distress calls or other weather
`alerts. A substantial portion of the battery power is
`generally consumed in this manner, and a further drain
`is the power drawn by the transmitter during operatiOn.
`Engine failure or other malfunction is another com-
`mon occurence with small craft which can deprive
`them of the headway needed for steering and put them
`in danger of capsizing as weather worsens. At such
`times sufficient battery power for the broadcast of re-
`quests for emergency assistance may constitute the mar-
`gin between life and death. Clearly the power con-
`sumed in monitoring the emergency and other channels
`may, in such circumstances, place in jeopardy the ade-
`quacy of battery power needed for emergency transmis-
`sions.
`
`It is therefore apparent that the monitoring for dis-
`tress calls and warnings which is essential
`to safety
`offshore may be the cause of serious depletion of battery
`power, posing the danger of communications cutoff.
`Thus, paradoxically monitoring for safety broadcasts
`may ultimately threaten the safety of the vessel's occu-
`pants. When this situation is aggravated by having a
`battery which, because of earlier deep discharges, has
`not or cannot be fully recharged, the danger is sharply
`increased.
`It is an object of the present invention to provide a
`novel battery-powered radiotelephone having both a
`battery-saver feature to prevent deep discharge and a
`battery power conservation feature to reduce the power
`consumption during channel monitoring and the time
`for recharging.
`It is also an object of the present invention to provide
`a radiotelephone in which such features are automati-
`cally operative so that the benefits are not dependent
`upon the actions or operating procedures of the user.
`Another object is to provide such a radiotelephone in
`which such features are provided relatively economi-
`cally by components which are relatively simple and
`long lived.
`SUMMARY OF THE INVENTION
`
`It has now been found that the foregoing and related
`objects may be readily attained in a transceiver which
`has a rechargeable battery, a transmitter, and a receiver.
`Switch means is connected between the battery and the
`transmitter and receiver, and it
`is operated between
`“on” and “off" conditions by switch actuating means.
`Circuit means connects the battery to the transmitter
`and receiver through the switch means.
`A timer circuit is connected to the receiver and trans-
`mitter, and it is operative to transmit an actuation signal
`to the switch actuating means upon receipt of a signal
`on the receiver or during operation of the transmitter. It
`is operative to disable the switch actuating means and
`thereby to maintain the switch means in an “off“ condi-
`tion during other periods to cut off power supply to the
`
`Kyocera PX 1031_5
`
`Kyocera PX 1031_5
`
`

`

`5,095,308
`
`4
`
`3
`receiver and transmitter. This disabling of the power
`supply is periodically interrupted for short intervals to
`provide power to the receiver and transmitter for such
`short intervals. If an enabling signal is received by the
`receiver. or the transmitter is operated, during such
`intervals.
`the timer circuit enables continued power
`supply through the switch means. Battery voltage de-
`tection means is also connected to the switch actuating
`means to provide a signal thereto enabling its operation
`to permit the switch means to be in an “on" condition
`only when the battery voltage is above a predetermined
`reference value.
`
`the transceiver includes squelch means
`Preferably,
`connected between the receiver and timer circuit, and it
`is adapted to limit the receiver output to signals having
`a predetermined signal strength whereby weak signals
`may be squelched. The battery voltage detection means
`includes a Zener diode providing a stabilized trigger
`voltage to a cutoff amplifier and a voltage divider pro-
`viding a biasing voltage to the amplifier. Thus, the am-
`plifier is actuated only when the trigger voltage is
`above the biasing voltage.
`Desirably, the switch actuating means is an AND
`gate receiving signals from the battery voltage detec-
`tion means and the timer circuit. The timer circuit in-
`cludes a sleep timer providing a long duration “off"
`condition and signal and a short duration “on" condi-
`tion and signal in which to determine ifthere is a signal
`on the receiver above a predetermined signal strength.
`A second timer is enabled by detection of a signal from
`the transmitter or the receiver to hold the sleep timer in
`an “on“ condition during such signal and for a limited
`period thereafter. A flip flop circuit component is con-
`nected between the receiver and the timers.
`In the preferred embodiment, the switch means is a
`pass transistor which is connected to the battery and to
`the switch actuating means to pass power to the re-
`ceiver and transmitter upon receipt of a signal from the
`switch actuating means and from the timer circuit. The
`transceiver also includes a manual “on-ofi“ switch.
`Desirably, there is included a visual indicator actuated
`by the battery voltage detection means, and means for
`overriding the battery voltage detection means to en-
`able an emergency transmission.
`In the method for operation of the novel transceiver,
`the transceiver is turned “on“ to enable its operation,
`and power is periodically provided to the receiver and
`transmitter for intervals of relatively short duration.
`During these intervals, it is determined whether there is
`a signal being received on the receiver or being gener-
`ated by the transmitter. If so, power continues to be
`supplied to the receiver and transmitter during the per-
`iod in which such a signal continues and for a limited
`period of time thereafter. Concurrently, the voltage of
`the battery power supply is checked to determine
`whether it
`is above a predetermined voltage. If not,
`further power drain from the battery power supply is
`precluded.
`Desirably, the power supply is interrupted for peri-
`ods substantially greater than the duration of the short
`intervals, and generally the period of interruption is
`7-15 times the length of the short intervals. Preferably,
`the transceiver includes a squelch circuit and the
`squelch circuit is adjusted to pass only signals above a
`selected strength for the step of determining whether
`there is a signal being received on the receiver.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a functional diagram of a radiotelephone
`embodying the present invention and showing its sub-
`systems and functions arranged in their functional se-
`quence:
`FIGS. 2A and 2B are signal-timing diagrams of the
`power conservation system; and
`FIG. 3 is a schematic diagram of the basic elements of
`the radiotelephone circuit showing how the battery-
`saver function and the power-conservation function are
`combined.
`
`DETAILED DESCRIPTION OF PREFERRED
`EMBODIMENT OF THE INVENTION
`
`1 illustrates the sequential operations of the
`FIG.
`major portions of the radiotelephone which are related,
`to the present invention. Two systems are of central
`importance—a power conservation system and a bat-
`tery saver system. These operate in conjunction with
`one another to achieve the objects of the invention.
`The power conservation system takes advantage of
`the fact that much of the time there are no transmissions
`on any given channel within the primary reception area,
`usually 15-20 miles. It'uses a timer to keep the receiver
`and transmitter in a dormant state almost 90 percent of
`the time, only "waking” them for brief, regular intervals
`to sample the monitored channel
`for any messages
`which are being broadcast, and readying the transmitter
`for possible use. This timer circuit is therefore referred
`to as having SLEEP and WAKE periods. When a mes-
`sage is received during a sampling interval, or if the
`transmitter is keyed, a second timer is started which
`overrides the SLEEP state of the first timer, WAKES
`the system, and keeps the power on for a period (conve-
`niently 10 seconds), to complete the reception or trans-
`mission of the message. If the message is of a duration
`longer than 10 seconds, the process repeats so often as is
`necessary.
`.
`Referring in detail to FIG. 1, the radiotelephone is
`first turned on as seen in function 50. The battery 25 is
`tested by condition test circuitry shown by function 51
`to determine if it is at level of charge which is HIGH,
`i.e., above a cutoff threshold, or LOW, i.e., below a
`cutoff threshold. If the latter is determined to be the
`case, then circuitry providing function 51 out puts a
`logical “0" signal to input port A of AND gate 21. This
`in turn causes gate 21 to output a logical “0” to pass
`device 24, blocking battery power from being supplied
`to the receiver 31 and the transmitter 32. The pass de-
`vice 24 can comprise any of a number of components,
`including FETs, SCRs, operational amplifiers, optical
`relays, etc. In addition, when battery 25 is at or below a
`predetermined level which represents substantial dis-
`charge, a warning light emitting diode (LED) 54 or
`other indicator will be lit by LED driver 55 to alert the
`user of the need for recharging the battery.
`However, if the battery 25 is determined to be at an
`acceptable level of charge, then the test circuit provid-
`ing the function 51 outputs a logical “1" to the AND
`gate 21. However, the AND gate 21 cannot output a
`logical “1” to turn on pass device 24 unless it also re-
`ceives a logical “1” at its second input port B. This
`logical “1” is provided at intervals by the output of the
`sleep timer 45, which is powered along with the squelch
`gate 36, the logic inverter 41, the JK flip-flop 42 and the
`lO-second timer 46, through power provided by the
`power lead 56 (connections are not shown).
`
`10
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`
`Kyocera PX 1031_6
`
`Kyocera PX 1031_6
`
`

`

`5,095,308
`
`5
`The sleep timer cycle is illustrated in FIG. 2A. 1t
`outputs a logical "0" (SLEEP) for 3 seconds, followed
`by a logical “1" (WAKE) that lasts for 0.3 seconds, an
`OFF/ON ratio of 10:1. During the 0.3 second WAKE
`interval. the logical “I" from the sleep timer 45 is input
`to input port B ofthe AND gate 21, and it provides the
`second logical “l“ needed for the gate 21 to output a
`logical “l“ of its own to the pass device 24, so that it
`will pass battery current to the receiver 31 and the
`transmitter 32.
`If the receiver 31 fails to receive a signal above the
`threshold of the squelch gate 36 during this interval,
`then the squelch gate 36 outputs a logical “0" which is
`inverted to a logical “1" by the logic inverter 41. This
`logical “1" output by the inverter 41 drives the JK
`flip-flop 42 to output a logical “1” from its right-side
`output port, restarting the sleep timer 45 for a further
`3.3 second SLEEP/WAKE cycle.
`However, if the receiver 31 receives during that in-
`terval a signal which exceeds the squelch threshold,
`then the squelch gate 36 outputs a logical “”.l The logic
`inverter 41 inverts this logical “l" to a logical “0"
`which drives the 1K flip-flop 42 to reverse its output
`signals. The result is that the sleep timer 45 now re-
`ceives from the flip-flop 42 a logical input of "0”, while
`the lO-second timer 46 now receives from the left-side
`output port of the flip-flop 42 a logical “l”, and the
`latter turns on the lO-second timer 46. The output of the
`timer 46 is a "HOLD“ signal on the signal line 47, and
`it controls the sleep timer 45 to hold its output state at
`a logical "1" level for 10 seconds, powering the receiver
`31 and the transmitter 32, and permitting the detected
`message to be received. If the message is longer than 10
`seconds, the sequence repeats for a further 10 seconds,
`and so on.
`Whenever the user switches on the transmitter 32, the
`lO-second timer 46 receives a logical “1" signal through
`the signal lead 58. This starts the lO-second timer 46 and
`results in the sleep timer 45 being held at its logical “1”
`output state, so that both the transmitter and the re-
`ceiver remain powered for so long as the ON switch
`(not shown) of the transmitter 32 is held closed. When
`the user releases that ON switch to end a transmission,
`the lO-second timer 46 remains on for 10 seconds
`longer, as though it had received a “start" trigger sig-
`nal. Thus, the receiver 31 will, during that lO-second
`period, remain powered to receive any replies to the
`message just broadcast. FIG. 2B illustrates the timing
`involved.
`Whenever the user holds the switch of the transmitter
`32 in its ON position, the transmitter 32 is powered
`unconditionally, i.e., regardless of the battery‘s state of
`charge, overriding any battery cutoff which may have
`been effected by the battery saver function. This is
`accomplished by the battery cutoff override 60, which
`turns on the pass device 24. To conserve power in the
`event that “battery low" LED 54 is lit, indicating that
`the battery 25 is nearing a discharged state, the user may
`choose to switch the transmitter 32 from its NORMAL
`output power setting to its LOW output power setting,
`with a switch provided for that purpose. Neither this
`switch nor its associated control circuitry is shown
`here, since they are not essential to the present inven-
`tion.
`
`FIG. 3 illustrates the basic circuitry of a typical em-
`bodiment of the present invention. Since many of its
`functional elements have already been described in
`detail in connection with FIG. 1, the following descrip-
`
`6
`tion will focus on those elements not previously de-
`scribed, commencing with the bridge network which
`compares the voltage of battery 25 with a reference
`voltage to determine the state of charge of the battery
`25. The bridge comprises the resistors 10 and 11 form-
`ing a two-element voltage divider in which the battery
`voltage fed to the top of the resistor 10 produces a
`current flow through the resistor 10 and resistor 11 to
`ground. This establishes a bias voltage level at the junc~
`tion 12 which can be compared with a stable reference
`voltage at the junction 15. The stable reference voltage
`at the junction 15 is established by the Zener diode 14,
`which draws current from the battery 25 through the
`currentelimiting resistor 13. The Zener diode 14 is typi-
`cally a device with a low temperature coefficient and
`which requires no auxiliary temperature compensation
`or stabilization over the entire range of ambient temper-
`atures it will encounter in operation. These two volt-
`ages, i.e., the bias level at the junction 12 and the refer-
`ence level at the junction 15, are fed to the differential
`amplifier 18 through the leads 16 and 17, respectively.
`So long as the bias voltage level is above a predeter-
`mined threshold, the differential amplifier 18 outputs a
`logical “1" into the signal lead 19, and thence to one of
`the input ports of the AND gate 21.
`The other input port of the AND Gate 21 receives by
`the signal lead 20, logic signals output by the sleep timer
`45. As previously described, whenever the sleep timer
`45 outputs a WAKE signal, i.e., a signal at a logical “1”
`level, the AND gate 21 will in turn output a logical “1”
`into the signal lead 22, and thence to the base 23 of pass
`transistor 24, turning on the pass device 24. When the
`radiotelephone's power switch 26 is closed, battery
`power is provided through the emitter 27 to the collec-
`tor output lead 29 to the junction 30. The junction 30
`then provides battery voltage to the receiver 31 and to
`the transmitter 32 through the power leads 70 and 71,
`respectively.
`If the battery 25 has a terminal voltage which is
`below the predetermined cutoff point, then the ampli-
`fier 18 will output a logical “0" which, when fed to the
`AND gate 21 through the signal lead 19, will cause the
`AND gate 21 to output a logical “0" regardless of the
`state of input of the sleep timer 45 to the signal lead 20.
`This will cut off power to the receiver 31 and the trans-
`mitter 32, saving the battery 25 from further possibly
`damaging discharge, unless the battery-saver function is
`overridden by the user’s effecting an emergency trans-
`mission despite the low battery charge.
`As shown the receiver 31 and the transmitter 32 share
`the antenna 34, and the interface 33 between them is to
`mute the receiver 31 during transmission. The potenti-
`ometer 37 is the volume control for audio amplifier 38
`and speaker 39. The receiver 31 drives the squelch gate
`36 through the signal lead 35. Not shown is a conven-
`tional squelch threshold control by which the signal
`strength of an incoming signal can be measured and the
`output of the squelch gate 36 limited thereby. As de-
`scribed earlier, the logical output of the squelch gate 36
`drives the logic inverter 41, which in turn drives the JK
`flip-flop 42, and thereby the sleep timer 45 and the
`lO-second timer 46 through the signal leads 43 and 44
`respectively.
`It will be appreciated that the circuit components
`may vary from those illustrated. A more complex bat-
`tery voltage comparator device may be employed to
`monitor voltage against a standard reference. The pass
`device is conveniently a pass transistor although a
`
`10
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`15
`
`20
`
`25
`
`30
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`35
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`
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`
`Kyocera PX 1031_7
`
`Kyocera PX 1031_7
`
`

`

`5,095,308
`
`7
`power FET, operational amplifer or optical coupler/-
`relay, and like devices serves as a “switch“ actuated by
`the AND gate may also be employed. Similarly, other
`electronic components may be substituted for the illus-
`trated AND gate.
`It will be appreciated that the described embodiments
`are merely illustrative of the principles involved, and
`that many alternative configurations can be readily
`devised by persons skilled in the art without departing
`from the spirit of these illustrative examples or from the
`principles disclosed in the present invention. For exam-
`ple, the selection of a low output power setting, when
`overriding a battery-saver cutoff in order to transmit,
`could be done automatically; several stable reference
`thresholds could be established for the battery condi-,
`tion, rather than just one, with specific user alerts or
`functional restrictions at each such threshold: the sleep
`timer could be designed to output different SLEEP and
`WAKE gate lengths, for example 2.7 seconds and 0.35
`seconds, respectively; and the 10-second timer could be
`designed to operate for a period that is shorter or longer
`than 10 seconds, and so forth.
`By having the squelch control circuit adjusted to
`limit reception of signals to those with sufficient signal
`strength to be of interest, the output to the timers can be
`limited to reduce actuation of the lO—second timer. The
`sleep timer limits the demand for power by the receiver
`and transmitter to its short wake times, and. as a result,
`power consumption is reduced. The battery condition
`monitoring circuit concurrently functions to disable the
`unit from constant functioning when the battery has
`reached a predetermined discharge level, at which
`point it can be overridden for an emergency use.
`Thus. it can be seen from the foregoing detailed speci-
`fication and attached drawings that the battery pow-
`ered transceiver of the present invention has novel bat-
`tery saving functions which are provided by relatively
`inexpensive and reliable components.
`Having thus described the invention, what is claimed
`
`15:
`
`1. In a transceiver, the combination comprising:
`(a) a battery;
`(b) a transmitter;
`(c) a receiver;
`(d) switch means connected between said battery and
`said transmitter and receiver;
`(e) switch actuating means operative to operate said
`switch means between “on" and “off“ condition;
`(0 circuit means connecting said battery to said trans-
`mitter and receiver through said switch means; and
`(g) a timer circuit connected to said receiver and
`transmitter and operative to transmit an actuation
`signal to said switch actuating means upon receipt
`on said receiver of a signal or during operation of
`said transmitter and to disable said switch actuating
`means and thereby maintain said switch means in
`an “off’ condition during other periods to cut of
`power supply to said receiver and transmitter, said
`disabling being periodically interrupted for short
`intervals to provide power to said receiver and
`transmitter for such short intervals, said timer cir-
`cuit enabling continued power supply through said
`switch means if an enabling signal is received by
`said receiver or said transmitter is operated a said
`timer circuit
`including timing means providing
`three timing periods comprising a sleep timer cir-
`cuit having two timing periods, comprising (i) a
`relatively long duration “off" period in which said
`
`8
`switch actuation means is disabled, (ii) a relatively
`short duration “on" period in which an actuation
`signal is provided to said switch actuation means to
`monitor said receiver to determine the existence of
`a signal to enable continued power supply, and a
`second timer having a third timing period compris-
`ing (iii) a relatively long “standby" period follow-
`ing termination of a transmission on said transmit-
`ter for receipt of a response on said receiver.
`2. The transceiver in accordance with claim 1 includ-
`ing battery voltage detection means connected to said
`switch actuating means to provide a signal thereto en-
`abling its operation to permit said switch means to be in
`an “on" condition only when the battery voltage is
`above a predetermined reference value.
`3. The transceiver in accordance with claim 2
`wherein said transceiver includes a squelch means con- .
`nected between said receiver and sleep timer circuit and
`adapted to limit the receiver output to signals having a
`predetermined signal strength whereby weak signals.
`may be squelched.
`in accordance with claim 2
`4. The transceiver
`wherein said battery voltage detection means includes a
`Zener diode providing a stabilized trigger voltage to a
`cutoff amplifier apd a voltage divider providing a bias-
`ing voltage to said amplifier, said amplifier being actu-
`ated only when said trigger voltage is above said biasing
`voltage.
`in accordance with claim 1
`5. The transceiVer
`wherein said switch actuating means is an AND gate
`receiving signals from said battery voltage detection
`means and said timer circuit.
`6. The transceiver
`in accordance with claim 1
`wherein said timer circuit includes a flip flop circuit
`component connected between said receiver and said
`timing means.
`in accordance with claim 1
`7. The transceiver
`wherein said switch means is a pass transistor which is
`connected to said battery and to said switch actuating
`means to pass power to said receiver and transmitter
`upon receipt of a signal from said switch actuating
`means.
`in accordance with claim 1
`8. The transceiver
`wherein said transceiver also includes a manual “on-
`ofi“ switch.
`in accordance with claim 2
`9. The transceiver
`wherein there is included a visual indicator actuated by
`said battery voltage detection means.
`10. The transceiver in accordance with claim 2
`wherein there is included means for overriding said
`battery voltage detection means.
`11. In a transceiver, the combination comprising:
`(a) a battery;
`(b) a transmitter;
`(c) a receiver;
`(d) switch means connected between said battery and
`said transmitter and receiver;
`(e) switch actuating means operative to operate said
`switch means between “on” and “off” condition;
`(0 circuit means connecting said battery to said trans-
`mitter and receiver through said switch means;
`(g) a timer circuit connected to said receiver and
`operative to transmit an actuation signal to said
`switch actuating means upon receipt of a signal or
`during operation of said transmitter and to disable
`said switch actuating means and thereby maintain
`said switch means in an “off" condition during
`other periods, to cut off power supply to said re-
`
`l0
`
`15
`
`20
`
`25
`
`30
`
`35
`
`45
`
`55
`
`65
`
`Kyocera PX 1031_8
`
`Kyocera PX 1031_8
`
`

`

`5,095,308
`
`10
`connected to said battery and to said switch actuating
`means to pass power to said receiver and transmitter
`upon receipt of a signal from said switch actuating
`means.
`
`9
`ceiver and transmitter, said disabling being periodi-
`cally interrupted for short
`intervals to provide
`power to said receiver and transmitter for such
`short intervals and to enable continued operation if
`an enabling signal is received by said receiver or
`said transmitter is operated. said timer circuit in-
`cluding timing means providing three timing peri-
`ods comprising a sleep timer circuit having two
`timing periods, comprising (i) a relatively long
`duration “off period in which said switch actuation
`means is disabled, (ii) a relatively short duration
`"on" period in which an actuation signal is pro-
`vided to said switch actuation means to monitor
`said receiver to determine the existence of a signal
`to enable continued power supply, and a second
`timer having a third timing period comprising (iii)
`a relatively long “standby" period following termi-
`nation of a transmission on said transmitter for
`receipt of a response on said receiver;
`(h) squelch means connected between said receiver
`and sleep timer circuit and adapted to limit the
`receiver output to signals having a predetermined
`signal strength whereby weak signals may be
`squelched; and
`(i) battery voltage detection means connected to said
`switch actuating means to provide a signal thereto
`enabling its operation to actuate said switch means
`into an “on" condition only when the battery volt-
`age is above a predetermined reference value.
`12. The transceiver in accordance with claim 11
`wherein said battery voltage detection'means includes a
`Zener diode providing a stabilized trigger voltage to a
`cutoff amplifier and a voltage divider providing a bias-
`ing voltage to said amplifie