JP3273946B2 - Portable electronic devices - Google Patents

Description

The present invention is a continuation-in-part of U.S. patent application Ser. No. 115,074, filed Sep. 2, 1993, which is hereby incorporated by reference. Is a continuation-in-part of U.S. Patent Application Serial No. 083,571, filed June 30, 1993.

BACKGROUND OF THE INVENTION The present invention relates generally to electronic devices that can be powered by a rechargeable power source, and more specifically, to reduce operating power to recharge an electronic device's rechargeable power source. Rechargeable power supply connectable to an external power supply that can be provided and related methods.

Many electronic devices are designed to be powered by a battery power source consisting of one or more battery cells. In some cases, battery power is provided to power the electronic device when the electronic device is not located or cannot be located near a permanent or other fixed, power supply. It is required to use. In other cases, battery power is used to power the electronic device to increase the portability of the device, which interconnects the electronic device with a permanent or other fixed power source. No power cable is required. Typically, one or more battery cells that make up the battery power used to power the electronic device are transported directly with the electronic device,
Alternatively, it is housed in an electronic device.

However, battery devices can store only a finite amount of energy, and thus powering electronic devices by the battery source is limited by the energy storage capacity of the battery source. Powering an electronic device with a battery power supply causes a discharge of the stored energy of the battery power supply. Once the stored energy of the battery power is discharged above a certain level, replacement of the battery power is required to allow continued operation of the electronic device. Increasing the energy storage capacity of a battery power source, such as by increasing the number of battery cells comprising such a battery power source, increases the size (and weight) of the power source. Such a method for increasing the energy storage capacity of a battery power source reduces the portability of the electronic device when the battery power source is carried with the electronic device. Thus, when designing a battery power supply, a compromise is made between increasing the energy storage capacity and reducing the portability of the electronic devices that carry such battery power.

Portable or portable radiotelephones are typically one such electronic device that is powered by battery power. Battery power is typically of a size and weight that is carried directly with the wireless telephone and does not unduly limit the portability of the wireless telephone. The wireless telephone includes a wireless transceiver circuit that includes a transmitting circuit and a receiving circuit that are operative to transmit and receive the modulated signal, respectively. In a typical operation of a radiotelephone, its receiving circuitry is constantly powered while waiting to receive a signal indicating an incoming call to the radiotelephone. Thereafter, the transmission circuitry of the radiotelephone is also enabled to transmit the powered and modulated signal therefrom.

Wireless telephones operating in many cellular communication systems are configured to transmit modulated signals therefrom and also receive modulated signals transmitted thereto simultaneously (transmitted by the wireless telephone and the wireless The modulated signal transmitted to the phone is transmitted over a separate frequency channel). A radiotelephone operating in another cellular communication system is configured to transmit and receive modulated signals during non-simultaneous periods, and the receiving and transmitting circuit during two-way communication with the radiotelephone The unit is powered during asynchronous periods.

The time that the wireless telephone's receiving circuitry is powered up while waiting for the transmission of a signal indicative of an incoming call thereto is hereinafter referred to as the time the wireless telephone is in "standby" mode. (Of course, wireless telephone users often provide operating power to the wireless telephone only when the user wants to initiate and subsequently perform the telephone call, and during other times the operating power is provided to the wireless telephone. It should be noted that the radiotelephone may not be provided and the radiotelephone may not be powered to receive the signal transmitted to it, ie the user of the radiotelephone receives the incoming call transmitted to the radiotelephone To operate the radiotelephone in "standby" mode, rather than only to power the radiotelephone during the time the user initiates the telephone call.) In general, the transmission circuitry of the radiotelephone Is greater than the amount of energy required to operate its receiver circuitry. Also, because the actual device is less than ideal, some portion of the energy applied to the radiotelephone is converted to thermal energy, resulting in an increase in the temperature of the radiotelephone. Because more energy is required to operate the transmitter circuitry of the radiotelephone, a correspondingly greater amount of heat is generated during operation of the transmitter circuitry of the radiotelephone than when only the receiver circuitry is operable. There are occurrences.

Rechargeable battery power supplies consisting of one or more rechargeable battery cells have been developed and are commercially available. Some of such commercially available, rechargeable battery power supplies have configurations designed to be used to power wireless telephones. It is convenient to use rechargeable battery power,
This is because the rechargeable battery cells of the power supply can be recharged by applying a charging current generated by a power supply. Once recharged, the rechargeable battery power can be reused. Some configurations of rechargeable battery power can be recharged and reused up to 500 times or more.

As mentioned previously, a rechargeable battery power supply typically consists of one or more battery cells. The cells are connected in series (or otherwise) and are typically housed in a common housing. The housing, together with the battery cells, constitutes a battery power source often referred to as a battery pack. For simplicity,
Such structures are also referred to generically by the general term "battery." In this specification, such a simplified terminology is often used.

The battery cells of a rechargeable battery power supply are formed from a variety of different materials of construction. For example, rechargeable battery cells include lithium (Li) materials, nickel-cadmium (Ni-Cd) materials, or nickel metal hydride (nick).
el metal hydride: NiMHO ₂ ) Composed of materials. Battery cells composed of these different materials exhibit different properties during their charging.

Battery chargers are also commercially available to allow recharging of rechargeable battery power. Battery chargers with such battery chargers typically supply operating power to recharge rechargeable battery power when properly connected to the charger to receive operating power. Consists of

The energy of the operating power supplied to the rechargeable battery power is converted to chemical energy and stored by the rechargeable battery cells of the battery power. Applying operating power to the battery cells over a period of time allows the rechargeable battery cells to fully recharge. However, because practical devices have less than ideal efficiency, some portion of the energy applied to the battery cells is converted to thermal energy, causing the battery cells to increase in temperature.

Some battery charging devices are of a structural type such that both the electronic device and the battery power source can receive operating power. Such a battery charger not only provides operating power for recharging rechargeable battery cells of the battery power source, but also provides operating power for enabling operation of the electronic device.

For example, structural battery chargers are available that allow a rechargeable battery pack with a radiotelephone to receive operating power to recharge the battery cells of the batterypack and enable operation of the radiotelephone circuitry. However, as mentioned earlier, in actual equipment, heat is generated as a by-product of the operation of the radiotelephone circuitry. Heat is also generated as a by-product of the process of recharging battery cells of a battery power supply.

A rechargeable battery structure consisting of battery cells from a rechargeable battery power supply shows a charge curve (which is a plot of voltage scaled as a function of time).
Over time, during recharging of a battery cell of such construction, the voltage level of the battery cell of the power supply increases as the amount of energy stored therein increases. Recharging a rechargeable power supply is most efficient when the voltage level of the power applied to the battery structure is slightly greater (eg, approximately one volt greater) than the voltage level of the battery structure. That is, recharging of certain battery structures is most efficiently performed when the voltage level of the power applied to recharge the battery "tracks" the voltage level of the rechargeable battery power supply. The voltage of the power applied to the rechargeable battery power source must be greater than the voltage level of the rechargeable battery power source so that energy can be transferred to the battery power source. However, if the voltage of the power applied to the battery power supply is much greater than the voltage level of the battery power supply, a significant portion of the energy corresponding to that voltage difference will be converted to thermal energy.

When the rechargeable battery power supply is implemented as part of an electronic device, such as a wireless telephone, the thermal energy generated while applying charging power to the rechargeable battery power supply heats the electronic device. Results. Heating such electronic devices can cause discomfort to the user of the electronic device and also affect its performance.

Therefore, what is needed is a means by which charging power can be applied to a rechargeable battery incorporated into an electronic device without causing excessive generation of thermal energy.

SUMMARY OF THE INVENTION Accordingly, the present invention provides devices and related methods that overcome the problems associated with existing technologies.

The present invention further advantageously provides an electronic device comprising a rechargeable power supply, wherein the electronic device reduces operating power for recharging the rechargeable power supply and also for operating electronic circuits of the electronic device. It can be connected to a variable level power supply that provides operating power to provide.

The present invention has further advantages and features, the details of which will become more apparent by reference to the following detailed description of a preferred embodiment.

Thus, according to the present invention, an electronic device connectable to a variable level power supply is disclosed. The variable level power supply to which the electronic device can be connected has a power supply control circuit that operates in response to receiving a power supply control signal for controlling a voltage level of operating power generated by the variable level power supply. The electronic device is operable to receive a selected, constant voltage level of operating power generated by the variable level power supply when connected to the electronic device. The electronic device includes a connector connectable to the variable level power supply. The connector includes at least a first connector portion and a second connector portion, wherein the first connector portion allows connection of the variable level power supply thereto, whereby the operating power generated by the variable level power supply Receive. The second connector section allows connection of a power supply control circuit of a variable level power supply thereto. A rechargeable power supply is coupled to receive the charging signal when the variable level power supply is connected to the first connector portion and operating power is generated by the variable level power supply. A voltage sensing circuit is operative to sense a voltage level of the rechargeable power supply and thereby generate a signal representative of the sensed voltage level. The signal representing the voltage level is transmitted to the second connector section of the connection element when the rechargeable power supply is within a selected range, and then to a power control circuit of the variable level power supply. A power control signal for applying is formed such that a power level of the power generated by the variable level power supply changes in response to a voltage level of the rechargeable power supply. A converter circuit is connected between a first connection element of the connection element and the rechargeable power supply and is generated by the variable level power supply and applied to a first connector portion of the connector. The operating power at the constant voltage level is converted to the operating power at the selected constant current level. The operating power at the selected constant current level forms a charging signal received by a rechargeable power supply.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention can be more clearly understood by reference to the following description in light of the accompanying drawings, in which: FIG. 1 is a graphical representation of a typical battery charge curve; The measured voltage across the output terminals of the battery cells of the rechargeable battery pack during charging is plotted as a function of time.

FIG. 2 is a block diagram of the electrical device of the preferred embodiment of the present invention connected to a variable level power supply.

FIG. 3 is a block diagram of a wireless transceiver according to a preferred embodiment of the present invention, similar to FIG. 2, but connected to a variable level power supply.

FIG. 4 is a partial block diagram and a partial circuit diagram of a part of the wireless transceiver of FIG. 3 and the electrical device of FIG. 2 according to another preferred embodiment of the present invention.

FIG. 5 is a schematic representation of a cellular radiotelephone, similar to the radio transceiver shown in block form in FIG. 3 of the preferred embodiment of the present invention.

FIG. 6 is a flowchart illustrating the method steps of the method of the preferred embodiment of the present invention.

FIG. 7 is a flow chart showing algorithmic method steps executable by a control circuit forming part of the wireless transceiver of the preferred embodiment of FIG.

Description of the Preferred Embodiment As mentioned earlier, portable electronic devices are often powered by a rechargeable power supply. When the stored energy of the rechargeable power supply is depleted, a battery charger is used to recharge the rechargeable battery cells of the rechargeable power supply.

The number of portable electronic devices that can be arranged with the rechargeable power source carried with it, so that the operating power can be provided for the rechargeable battery cells of the rechargeable power source and also for the circuitry of the electronic device A battery charger having such a structure is available.

Battery chargers typically include circuitry that causes the current level of operating power generated by the battery charger to be independent of voltage. However, because the power transfer between the battery charger and the electronic device is not completely efficient, some of the energy of the operating power generated by the battery charger is converted to thermal energy, which is converted to electronic energy. Increase the temperature of the device. Also, if the voltage level of the operating power generated by the battery charger is significantly higher than the voltage level of the battery cell of the rechargeable power supply, a large portion of the operating power generated by the battery charger is converted to thermal energy. Is converted. As a result, the temperature of an electronic device powered by such a rechargeable power supply will exhibit a significant temperature rise. In the particular case where the electronic device comprises a wireless telephone operating in a cellular communication system, the conversion of the operating power generated by the battery charger to thermal energy causes an increase in the temperature of the wireless telephone. Such an increase in the temperature of the radiotelephone may not only affect the performance of the radiotelephone but also result in discomfort to the user of the radiotelephone. Also, an increase in the temperature of the battery cell of the radiotelephone (or other electronic device) may further cause the battery charger to apply operating power, particularly in response to the battery cell temperature exceeding a selected threshold. Operation to terminate will result in incomplete recharging of the battery cells.

By having the voltage level of the operating power generated by the battery charger track the voltage level of the rechargeable battery cells of the rechargeable power supply, the operating power generated by the battery charger converted to thermal energy The amount of energy is minimized.

If the battery charger has a variable level power supply, the voltage level of the operating power generated by such a power supply need not be a constant voltage level. Alternatively, the voltage level of the operating power can be varied, thereby reducing the amount of energy that is converted to thermal energy during recharging of the battery cells of the rechargeable power supply.

By giving an indication of the voltage level of the battery cell of the rechargeable power supply to the variable level power supply with the battery charging device, the variable level power supply corresponds to the voltage level of the battery cell of the rechargeable power supply, Operation can be performed to generate operation power at a voltage level slightly higher than the voltage level, and heat generation during recharging of the battery cell can be reduced.

As mentioned previously, the voltage level of the battery cell of the rechargeable power supply increases as the amount of energy stored by the battery cell increases during the application of operating power to the battery cell.

Battery cells made of nickel-cadmium material are preferably used because such battery cells can be charged by supplying a relatively large charging current thereto. Such a battery cell can be recharged in a relatively short period of time because a relatively large charging current is available to recharge the nickel-cadmium battery cell. However, care must be taken when applying a relatively high charge current level of operating power to a battery cell, which once the battery cell is fully recharged, will lose its relatively high charge current level of operating power. This is because the continuous application of the battery cell causes a large temperature rise of the battery cell and damage to the battery cell.

FIG. 1 is a graphical representation of a typical battery charge curve for a nickel-cadmium rechargeable battery cell.
The battery charge curve is formed from a plot of the voltage measured at the output terminal of a nickel-cadmium rechargeable battery cell as a function of time.

In FIG. 1, scaled with respect to volts,
Voltage is plotted along the ordinate axis 10 and time scaled in seconds is represented along the abscissa axis 12. The resulting curve 14 increases over time substantially as a function of the operating power applied to the battery cell to recharge the battery cell. However,
As shown, the general increase is not linear. curve
Points 16 and 17 on 14 represent voltage levels at which the current level of operating power applied to the battery cells of the rechargeable battery power source changes. At the beginning, and during the period shown in the figure by the "rapid charge phase", the current level of the operating power applied to the battery cells is relatively high. Next, during the period labeled "trickle charge phase" in the drawing (corresponding to the portion of curve 14 between points 16 and 17), the current level of operating power supplied to the battery is reduced by a first reduction. It is the value which was done. Thereafter, during the period indicated as “maintenance charging phase” in the drawing, the current level of the operating power applied to the battery cell has the second reduced value.

Characteristic charging curves for other types of battery structures can be shown as well. While such other types of battery structures have other characteristically shaped charging curves, it generally applies that the voltage substantially increases as a large amount of energy is stored by such batteries. In any case, the generation of thermal energy is reduced by having the variable level power supply having the battery charger track the voltage of the battery cells that apply the operating power.

Turning now to the block diagram of FIG. 2, there is shown an electronic device, generally referred to by the numeral 100, of a preferred embodiment of the present invention. The electronic device 100 is connected to the variable level power supply 106 and can be disconnected therefrom. Variable level power supply 106
Includes a power supply control circuit 112 as a part thereof. Control circuit 112
Operates to control the voltage level of the operating power generated by the variable level power supply 106 so that the operating power generated by the variable level power supply 106 is a constant voltage of the level selected by the control circuit 112. , A constant voltage. The variable level power supply 106 is connected by a plug member 142 to the electronic device 100 via a cable 118 consisting of lines 124, 130 and 136. Plug member 142 is releasably connectable to a plug connector 148 having connection elements 154, 156 and 158 for receiving lines 124, 130 and 136, respectively. Next, the variable level power supply 106 can be connected to a traditional domestic power supply (by connection with a plug connector 160) or to another suitable power supply.

Variable level power supply 106 operates to generate any of a variety of voltage levels of operating power on line 124 of cable 118. The operating power of any of the various voltage levels generated on line 124 forms a constant voltage signal.

Line 164 of electronic device 100 is connected to connection element 154 and operates to supply converter circuit 168 with the operating power received at connection element 154.

The converter circuit 168 operates to convert the constant-voltage operation power to a constant-current operation power, and in the preferred embodiment includes a resistor 172 and a diode 176 connected in series. The voltage drop across resistor 172 is determined by the resistance of the resistor, and the voltage drop across diode 176 is determined by the physical characteristics of the diode. The resistance of the circuit 168 is determined by the resistance of the resistor 172. Therefore, the operating power at the output of converter circuit 168 is at a constant current level.

The constant current operating power generated at its output by converter circuit 168 is provided by line 184 to a rechargeable power supply 180. Rechargeable power supply 180 is coupled to receive a constant current operating power generated at the output of converter circuit 168, here a battery cell 188.
And at least one rechargeable battery cell represented by Rechargeable power supply 180 is also connected to ground by line 192.

The constant current operating power generated at the output of converter circuit 168 is further provided to electronic circuit 196 of electronic device 100 via line 198. The operating power generated by the converter circuit 168 is the power supply 180 thereby rechargeable.
Operable to recharge and also power electronic circuit 196. Thus, when the variable level power supply 106 is not coupled to the electronic device 100, the energy stored by the battery cells of the rechargeable power supply 180 is used to power the electronic circuit 196.

Line 202 is further connected to the output of converter circuit 168. Line 202 is also coupled to a first side of switch circuit 206. The second side of the switch circuit 206 is connected to the connection element 156 of the plug connector 148.

When the switching circuit 206 is in the closed position,
Connection element 156 is maintained at the same voltage level as the output voltage level of converter circuit 168. Converter circuit 16
Since the output of 8 is coupled to the battery cell 188 of the rechargeable power supply 180, thereby at the same voltage level as the battery cell, the connection element 156 will also be at the same voltage level as the battery cell 188. I have. When line 130 is connected to connection element 156 and switch circuit 206 is in the closed position, an indication of the voltage level of battery cell 188 is provided.

When switching circuit 206 is in the closed position and plug 142 is connected to plug connector 148, the voltage level of battery cell 188 of rechargeable power supply 180 is provided on line 130 of cable 118 of variable level power supply 106 Is done.

Line 130 is then coupled to power control circuit 112,
The power supply control circuit 112 operates to control the voltage level of the operating power generated by the power supply 106 on line 124. The voltage level of the operating power generated by the variable level power supply 106 is thereby adapted to track the voltage level of the battery cells 188 of the rechargeable power supply 180. In a preferred embodiment of the present invention, the voltage level of the operating power generated by power supply 106 is
And the minimum voltage level is 7.4 volts and the maximum voltage level is 10.1 volts. Since the voltage level of the operating power generated by the power supply 106 on line 124 is a voltage level that tracks the voltage level of the rechargeable battery cell 188 of the rechargeable power supply 180, the battery cell 188 is recharged. Can be performed efficiently.

When switching circuit 206 is in the open position, connection element 156 is not connected to the output of converter circuit 168, but rather is connected to ground by resistor 210.

The rechargeable power supply 180 further comprises a thermistor 216 located near the battery cell 188 of the rechargeable power supply 180. Thermistor 216 is connected to temperature detection circuit 224
Operate to generate a signal on 220 indicating the temperature level of battery cell 188.

In the preferred embodiment shown in FIG. 2, the temperature sensing circuit 224 is configured in a comparator structure for comparing the sensed temperature level and the threshold voltage represented by the signal generated by the thermistor 216. It comprises a comparison circuit including an operational amplifier 230. If the sensed temperature of the battery cell 188 is greater than the threshold voltage, as indicated by the signal generated by the thermistor 216 on line 220, the operational amplifier 230 generates a signal on line 236. Line 23
The value of the signal generated on 6 determines the positioning of the switching circuit 206.

If the signal generated on line 220 by thermistor 216 indicates that the temperature level of battery cell 188 is below a preselected level, temperature sensing circuit 224 causes a signal to be generated on line 236. Then, the switching circuit 206 is placed in the closed position. However, if the signal generated on line 220 by thermistor 216 exceeds a preselected level,
If so, the temperature sensing circuit 224 generates a signal on line 236 to place the switching circuit 206 in the open position.

As a result of controlling the positioning of the switching circuit 206 in response to the temperature level of the battery cell 188, the application of operating power to recharge the battery cells of the power supply 180 that can be recharged by the variable level power supply 106 Depends on the cell temperature level. As mentioned earlier, the temperature level of the battery cell during the application of the charging current increases at a large rate when the battery cell has been sufficiently charged. Thus, a large rate or rate of increase in the temperature of a battery cell indicates a full charge of the battery cell. When switching circuit 206 opens in response to a signal generated on line 236 when the temperature level of battery cell 188 exceeds the preselected level, connection element 156 and then to power supply control circuit 112. The extending line 124 is connected to ground when the battery cell 188 is fully charged. In the preferred embodiment, during such time, power supply control circuit 112 determines that the operating power generated by variable level
The minimum level is set to prevent charging at the high charge rate of 88, but is set to a level large enough to allow the operation of the electronic circuit 196 by the operating power generated by the variable level power supply 106.

FIG. 3 is a block diagram of a preferred embodiment of the present invention.
FIG. 3 is a block diagram of a wireless transceiver similar to that of FIG. The wireless transceiver 300 is detachably connected to a variable level power supply 306. Variable level power supply 306 operates to generate a constant voltage level of operating power for any of a variety of voltage levels. The voltage level of the operating power generated by the variable level power supply 306 is controlled by the power supply control circuit 312.

The variable level power supply 306 is detachably connectable to the wireless transceiver 300 by a cable 318 having lines 324, 330 and 336, and the lines 324, 330 and 336 are plug members.
It can be connected to the plug connector 348 of the wireless transceiver 300 via 342. Plug connector 348 is a connecting element 3 which receives lines 324, 330 and 336 in a separable engagement.
Consists of 54,356 and 358.

Line 364 is the connection element 354 of the plug connector 348
Is connected to the converter circuit 368. When a constant voltage level of operating power is generated by the variable level power supply 306 on line 324, line 364 operates to provide such operating power to the converter circuit 368. As with the converter circuit 168 of the electronic device 100 of FIG. 2, the converter circuit 368 preferably comprises a series combination of a resistor and a diode, here a resistor 372 and a diode 376. The converter circuit 368 operates to convert the operating power at the constant voltage level to the operating power at the constant current level at the output of the converter circuit 368.

The constant current level of operating power generated by converter circuit 368 is applied to rechargeable power supply 380 by line 384 to provide charging current to battery cells 388 of rechargeable power supply 380. Battery cell 388 is further connected to ground by line 392. Thereby, when the variable level power supply 306 is coupled to the wireless transceiver 300 to provide operating power thereto, a constant current level of operating power can be recharged, thereby recharging the battery cells. The power can be supplied to the battery cell 388 of the power supply 380.

The output of the converter circuit 368 is further connected by a line 398 to a wireless transceiver circuit 396, which is shown here as comprising a transmitting circuit portion and a receiving circuit portion. With such a connection, the operating power provided by the variable level power supply 306 to the wireless transceiver 300 can also be used to power the wireless transceiver circuit 396 to enable operation of the circuit 396. Also, rechargeable power supply 380 battery cell 388
Also wireless transceiver circuit 39 via lines 384 and 398
6, the energy stored by the battery cell 388 can be used to power the circuit 396 when the variable level power supply 306 is not connected to the wireless transceiver 300.

Line 402 is also connected to the output of converter circuit 368 and operates to interconnect converter circuit 368 with switch circuit 406, which is shown here as consisting of a field effect transistor switch. The switch circuit 406 forms a short circuit or an open circuit depending on a voltage level present at a gate electrode of a transistor included in the switch circuit 406. The switch circuit 406 is further connected to the connection element 35 of the plug connector 348.
Connected to 4.

Thus, when the switch circuit 406 forms a closed circuit, the voltage level at the output of the converter circuit and also the battery cell 388 of the rechargeable power supply 380 is applied to the connection element 330 of the plug connector 348. When the variable level power supply 306 is connected to the wireless transceiver 300 and the transistor switch 406 forms a short circuit, the voltage level of the battery cell is provided to the power control circuit 312 by the line 330 of the cable 318.

In a manner similar to the operation of the variable level power supply 106 and power supply control circuit 112 of FIG. 2, the constant voltage operating power generated by the variable level power supply 306 is a level corresponding to the voltage level of the battery cells 388 of the rechargeable power supply 380. Is chosen. As before, in the preferred embodiment, the voltage level of the operating power generated by variable level power supply 306 is at a voltage level that is slightly greater than the voltage level of battery cell 388. Thereby, recharging of the battery cell 388 can be efficiently performed by the operating power generated by the variable level power supply 306.

Conversely, if the transistors making up switch 406 form an open circuit, connection element 356 is connected to ground by a resistor 410 and, as before, the variable level power supply in a manner similar to the operation of variable level power supply 106 of FIG. Operation 306 is performed.

Thermistor 416 is located in close proximity to battery cell 388 to determine the temperature level of the battery cell. Also, as shown, in the preferred embodiment, the thermistor 416 is located in a rechargeable power supply 380. The signal generated on line 420 by thermistor 416 is a battery cell 388
Shows the temperature level of Line 420 is a processing circuit 42 for providing a signal thereto indicative of the temperature level of battery cell 388.
Connected to 4. Processing circuit 424, in the preferred embodiment, comprises a microprocessor-type device having an algorithm configured to generate a signal on line 430 in response to a signal provided to circuit 424 by line 420. Line 430 is coupled to the gate electrode of transistor switch 406, thereby biasing the gate electrode. The characteristics of the transistor switch 406 thereby depend on the temperature level of the battery cell 388.

Similar to the operation of the electronic device 100 and the switching circuit 206 forming part thereof, the transistor switch 406 is shorted if the battery cell 388 is below a selected temperature and the battery cell 388 is selected. An open circuit is established when the temperature is exceeded. In another preferred embodiment, processing circuit 424 operates to generate a signal on line 430 to cause switch 406 to form an open circuit when the rate of temperature change of battery cell 388 is greater than a selected value. The variable level power supply 306 tracks the voltage level of the battery cell 388 only when the transistor switch 406 forms a short circuit, so that the variable level power supply 306 is used when the battery cell is at a lower temperature level than the selected temperature level. Only provides operating power to recharge battery cells 388.

The wireless transceiver 300 is further shown as including a charge indicating circuit 442, which is shown here as comprising a light emitting diode 446 and a current limiting resistor 450. The anode of diode 446 is coupled by line 364 by line 454 and the cathode of diode 446 is connected by a current limiting resistor 450 to the gate electrode of transistor switch 406. Light emitting diode 446 is a rechargeable battery pack 3
Operating power at a voltage level large enough to allow recharging of the 80 battery cells 388 is selected to be a characteristic that provides an indication of the period during which it is being generated on line 364. Thus, the visible signal generated by light emitting diode 446 indicates the time during which the charging current is provided to battery cell 388 of rechargeable power supply 380.

Since converter circuit 368 converts the operating power supplied thereto to a constant current level of operating power to recharge battery cell 388 at the desired current level, and also the operating power generated by variable level power supply 306 is Since the voltage level of the battery cell 388 is tracked only when the temperature level of the battery cell is lower than the selected temperature level,
Recharging of the battery cells 388 is performed efficiently. Also, the current level of operating power supplied to the battery cell 388 is determined when the battery cell 388 is fully recharged (as indicated by a large rise in the temperature level of the battery cell 388 as detected by the thermistor 416). It can be reduced quickly.

FIG. 4 is a circuit diagram of the converter circuit 168 of the electronic device 100 of FIG.
Can be used instead of 68, here reference numeral 46
FIG. 9 is a partial block diagram and a partial circuit diagram of a converter circuit, which is referred to by 8.

Similar to lines 164 and 364 of FIGS. 2 and 3, respectively, line 564 is connected to receive a constant voltage level of operating power generated by a variable level power supply. Line 564 is connected to a converter circuit 468 to convert the constant voltage level operating power to a constant current level operating power. Similar to converter circuits 168 and 368 in the previous figure, converter circuit 468 includes a series connected resistor-diode combination, here a resistor 572 and a diode 57.
6, consisting of: The resistor-diode combination circuits 572-576 operate in a manner similar to the operation of the resistor-diode combination circuit of the converter circuit of the previous figure.

Converter circuit 468 further includes a transistor switch 578 connected in series with diode 576, and a diode 576 connected in series and a second diode 580 connected in parallel with transistor switch 578. The gate electrode of transistor switch 578 is connected to a control circuit 582, which biases the gate electrode of switch 578 to make transistor switch 578 either a closed circuit or an open circuit. Works as follows. When transistor switch 578 forms a closed circuit, converter circuit 468 operates in the same manner as converter circuits 168 and 368 of the previous figure. However, when transistor switch 578 forms an open circuit, a separate resistor-diode combination circuit is formed between resistor 572 and diode 580. By selecting the characteristics of the diodes 576 and 580 to be different from each other, for example, selecting the diode 576 to exhibit a 0.3 volt voltage drop therebetween and the diode 580 to exhibit a 1.0 volt voltage drop therebetween. Thus, the current level of the operating power generated at the output of converter circuit 468 can be different depending on the position of transistor switch 578.

That is, when transistor switch 578 is in the closed position, the operating power generated at its output by converter circuit 468 can be selected to be one of two different values.

In this way, a charging current of one of two different values can be supplied to the battery cell of the rechargeable power supply.

[More specifically, in a preferred embodiment of the present invention,
When the transistor switch 578 forms a closed circuit, a fast charge current (operating power at a relatively high current level) is supplied to the battery cell of the rechargeable power supply, and the transistor switch 578 forms an open circuit. A trickle charge current (ie, a low current level of operating power) is supplied to the battery cell of the rechargeable power supply. The use of converter circuit 468 is particularly useful when rechargeable battery cells are nickel metal hydride (nickel meta).
l hydride) is advantageous when composed of materials. Once the battery cell of nickel metal hydride material is fully charged, the operating power supplied to the battery cell is low (relative to the current level that can be supplied to the battery cell of nickel cadmium material). Must be of current level. Diode 580
By properly selecting the characteristics of the converter circuit 46,
The operating power at the output of 8 can be at the desired low current level when switch 578 is open.

Also, the diode 580 has a current level at which the operating power at the output of the circuit 468 allows the powering of electronic circuits, such as the circuits 196 or 396 of FIGS. 2 and 3, respectively, regardless of the presence of a rechargeable power supply. Can be selected to have characteristics that will result in

Also, resistor 572 and diodes 576 and 580 are selected to have predetermined characteristics, and switches 578 and 406 (or 206 in FIG. 2) provide operating power at a first current level when both switches are closed. (Eg, high current level), a second current level (eg, low current level) when only switch 578 is closed, and a third current level (eg, low current level) when both switches are open. , Very low current levels).

Turning now to the circuit diagram of FIG. 5, a wireless telephone, generally referred to by reference numeral 600, is shown. Wireless telephone 600 corresponds to wireless telephone 300 shown in the block diagram of FIG. Wireless telephone 30 shown in block form in FIG.
The zero element is located within the housing of the wireless telephone 600 of FIG. 5, except for a rechargeable battery power supply 380, shown here as having a battery pack 620.

The wireless telephone 600 is connected to a variable level power supply 606 by lines 624,630 and 636, which connect the power supply 606 to the wireless telephone 6 through a plug connector 648.
Connect to the 00 connection element. (The connection elements of the radiotelephone 600 are hidden from view in the drawing, but correspond to the connection elements 354, 356, and 358 of FIG. 3.) A plug connector 660 is also shown in the drawing and connects the power supply 606 to a traditional home use. The power supply can be connected. (Plug connector 660 consists of a plug connector that allows connection to a traditional household power supply, but other plug connectors that allow connection to other types of power supplies are of course equally usable.) Power supply 606 is located away from wireless phone 600,
Since the wireless telephone 600 is connected to the wireless telephone 600 by the lines 624, 630 and 636, the wireless telephone 600
It can be suitably operated by the user despite the connection between Because the voltage level of the operating power generated by power supply 606 tracks the voltage level of the battery pack, recharging the battery cells of the battery pack is performed efficiently without converting excessive amounts of energy to thermal energy. .

Turning now to the logical flow diagram of FIG. 6, each method step of a method, generally referred to by the reference numeral 700, of a preferred embodiment of the present invention is shown. The method comprises selecting a constant voltage generated by a variable level power supply having a power control circuit operable in response to receiving a power control signal to a wireless telephone having a transceiver circuit when the variable level power supply is connected to the wireless telephone. Provides a level of operating power.

Initially, and as indicated by block 706, a variable level power supply is connected to the wireless telephone. And block 71
As shown at 2, a rechargeable power supply is connected to receive a charge signal in response to the variable level power supply being coupled to provide operating power to the wireless telephone.

Next, as indicated by block 718, the transceiver circuit is provided with operating power generated by a variable level power supply or power generated by energy stored by a rechargeable power supply.

Next, as shown at block 724, a signal representative of the voltage level of the rechargeable power supply is generated, where the signal representing the voltage level forms a power supply control signal for application to the variable level power supply. . Next, the power control signal is supplied to a power control circuit of the variable level power supply so that the selected voltage level of the power generated by the variable level power supply changes according to the voltage level of the rechargeable power supply. Is done.

Finally, and as shown by block 730,
The selected constant voltage level operating power generated by the variable level power supply and supplied to the radiotelephone is converted to a selected constant current level operating power, wherein the selected constant current level operating power is Form a charging signal received by a rechargeable power supply.

Finally, turning to the flowchart of FIG. 7, the wireless transceiver 30 of FIG.
Shown are method steps of an algorithm that can be executed by a control circuit forming part of zero.

Initially, as indicated by start block 806, after entry to the program, a temperature sensing signal indicative of the temperature level of the battery cells of the rechargeable power supply is provided,
Applied to the control circuit, as shown at 812.

Next, and as indicated by decision block 818, a determination is made as to whether the sensed temperature level is within a desired temperature range. If the temperature level is outside the desired range, a no branch is taken to block 812 and the process is repeated. If the temperature level is within the desired range, a yes branch is taken to block 8
The power is then supplied to the wireless telephone by the variable level power supply 306, where the transmitter switch is closed and the voltage level tracking the voltage level of the battery cell of the rechargeable power supply is closed.

Next, and as indicated by block 830, a temperature sensing signal indicative of the temperature level of the battery cell of the rechargeable power supply provided to the control circuit is again monitored.

Next, and as indicated by block 836, a determination is made as to whether the sensed temperature level is still within the desired temperature range. If so, the yes branch is taken to block 830 and the process is repeated. Otherwise, a no branch is taken to block 842, where the switch is opened and the operating power supplied to the battery cell of the rechargeable power supply no longer tracks the voltage level of the battery cell.

The interrupt branch, indicated by reference numeral 850, is further illustrated in the figures. The interrupt branch is executed when the radiotelephone activates the transmission circuit of block 396 in FIG. The interrupt branch can be called at any time during the execution of blocks 806-842.

Next, as indicated by block 862, the switch 206 is closed and a voltage level operating power tracking the voltage level of the battery cell of the rechargeable power supply is provided to the wireless telephone by the variable level power supply 306. .

Next, if the wireless telephone is in the process of recharging the rechargeable power source, as indicated by block 868, the temperature of the rechargeable power source is stored in memory. That is, if the switch 206 is closed when the interrupt branch is called, the temperature of the rechargeable power supply is stored.

As indicated by block 874, a determination is made as to whether the transmission circuitry of the wireless telephone is still enabled. If the transmit circuit is still enabled, a YES branch is taken and block 874 is executed again. If the transmit circuit is no longer enabled, a no branch is taken and switch 206 is opened as shown in block 880.

As shown in block 886, a determination is made as to whether switch 206 is closed when the interrupt branch is called. That is, if the radiotelephone is in the process of recharging a rechargeable power supply when the interrupt branch is taken, a yes branch is taken. If the radiotelephone is not in the process of recharging the rechargeable power supply, a no branch is taken to block 894 and the software returns from the interrupt branch. If the yes branch is taken, block 888
The temperature of the rechargeable power supply is blocked, as indicated by
A determination is made as to whether it is equivalent to the temperature stored during 868. If the temperature of the rechargeable power supply is greater than the temperature stored during block 868, a no branch is taken. If the temperature of the rechargeable power supply is block 86
If it is less than or equal to the temperature stored during 8, a YES branch is taken to block 890.

Next, as shown in block 890, the switch 206 is closed and the variable level power supply 306 again provides operating power at a voltage level that tracks the voltage level of the battery cells of the rechargeable power supply.

Next, and as shown in block 892, the software flow returns from the interrupt branch.

Although the present invention has been described with reference to the preferred embodiments illustrated in the various drawings, other similar embodiments can be used and described to achieve the same functions as the present invention without departing from the present invention. It should be understood that modifications and additions can be made to the embodiments described. Therefore, the present invention should not be limited to any single embodiment, but rather construed in breadth and scope in accordance with the appended claims.

Continuing on the front page (72) Inventor Kamuk James F. Illinois, United States 60048, Libertyville, West Lincoln 153 (72) Inventor Demro David Em, Illinois, United States 60013, Carrie, Claire Lane 337 (56) Reference Document JP-A-3-107339 (JP, A) JP-A-5-160774 (JP, A) UK Patent Application Publication 2224793 (GB, A) UK Patent Application Publication 2242794 (GB, A) UK Patent Application Publication 2239567 (GB , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H02J ⁷ /00-7/12 H02J 7/34-7/36 H02J 1/00 H04B 7/26

Claims (9)

(57) [Claims] A portable electronic device capable of performing a recharging operation using an external power supply for supplying a variable voltage to the portable electronic device in response to a power supply voltage control signal in addition to a main function of the portable electronic device. The portable electronic device connects the variable voltage from the external power supply to the portable electronic device via a first connection element and outputs the variable voltage from the portable electronic device. A connector for connecting the power supply voltage control signal to the external power supply via a second connection element, operably coupled to the first connection element to receive the variable voltage from the external power supply, and A charging circuit for generating a charging current from a power supply; at least one rechargeable battery cell operably coupled to the charging circuit for receiving the charging current; Detecting a voltage level of the rechargeable battery cell connected between the second connection elements and externally supplying the power supply voltage control signal having a voltage level that follows the voltage level of the rechargeable battery cell. A voltage detection connection provided to a power supply, a control circuit for generating a switching control signal based on a temperature of the rechargeable battery cell, the rechargeable battery cell, the control circuit, and the second connection element Power control for operably connecting the power supply voltage control signal from the voltage sensing connection to the external power supply via the second connection element based on a switching control signal from the control circuit. A switch circuit, and performs a primary function of the portable electronic device and is operatively connected to the rechargeable battery cell. Receiving power from the rechargeable battery cell when the external power source is absent during operation of the portable electronic device, and operably coupled to the external power source, wherein the rechargeable battery cell is A portable electronic device comprising: an electronic circuit that receives power from the external power supply when the external power supply is present, whether or not it is present. 2. The system of claim 1, wherein said charging circuit is a diode and resistor pair operably coupled to said first connection element and said rechargeable battery cell and connected in series, said selected voltage drop being in said pair. And having a selected characteristic impedance having a value sufficient to convert the variable voltage from the external power supply into a charging current to charge the rechargeable battery cell. The portable electronic device according to claim 1, further comprising a constant charging current regulator. 3. The portable electronic device according to claim 1, wherein said portable electronic device further comprises a transceiver, and said electronic circuit comprises a part of said transceiver. 4. The apparatus according to claim 1, further comprising a temperature detection circuit for detecting a temperature level of said rechargeable battery cell and inputting a temperature detection signal to said control circuit. Portable electronic devices. 5. The temperature sensing circuit includes a thermistor disposed within the at least one rechargeable battery cell and a temperature threshold sensing circuit coupled to the thermistor, wherein the temperature sensing circuit includes a thermistor. The method of claim 1, wherein the rechargeable battery cell is operable to generate a temperature sensing signal of at least a first selected value when the rechargeable battery cell indicates that the temperature exceeds a selected temperature level. 5. The portable electronic device according to 4. 6. The temperature detection signal generated by the temperature threshold detection circuit is supplied to the power control switch circuit, and the power supply voltage control signal is connected to the second connection in accordance with a value of the temperature detection signal. The portable electronic device according to claim 5, wherein the portable electronic device is connected to an element. 7. The power control switch circuit comprises a transistor circuit and the temperature detection signal generated by the temperature detection circuit and applied to the power control switch circuit is coupled to the transistor circuit to bias the transistor circuit. The portable electronic device according to claim 6, wherein: 8. An indicator circuit for indicating that operating power at a power level at least equal to or higher than a selected power level is being supplied to said first connection element of said connector. A portable electronic device according to claim 1. 9. The portable electronic device according to claim 1, wherein said portable electronic device is a radiotelephone and said electronic circuit comprises at least a part of a radiotelephone.