Telecommunications – Receiver or analog modulated signal frequency converter – With particular receiver circuit
Reexamination Certificate
1998-10-28
2001-04-24
Kuntz, Curtis (Department: 2743)
Telecommunications
Receiver or analog modulated signal frequency converter
With particular receiver circuit
C455S039000, C455S572000
Reexamination Certificate
active
06223025
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a radio selective-calling receiver which in particular maintains stable operation with a sufficient power supply.
Description of the Related Art
Generally, a conventional radio selective-calling receiver operates with one dry battery and has an intermittent operation in order to extend battery life, and only at the time when the data corresponding to the ID of a receiver owner are received, a radio section is switched on and the data are taken in. However, a controller of the radio section always operates to control the operation timing of the radio section. To operate the controller, at least about 2 volt is needed in the current available CPU and so forth, and to supply the voltage, for example a step-up transformer type DC/DC converter as shown in
FIG. 1
is used.
In
FIG. 1
, a transistor
511
is switched on or off by an oscillator
512
and at the “on” state of the transistor
511
, the energy supplied from a battery
510
is stored in a coil
513
and when the transistor
511
is turned “off”, the energy is supplied to a capacitor
515
via a diode
514
. With these operations, at the both terminals of the capacitor
515
, the step-upped output voltage Vout is generated.
In this case, by the switching operation of the transistor
511
, the switching noise as shown in
FIG. 2
is included in an output wave form and the higher harmonic waves of this switching noise is radiated and has a bad influence on the characteristics of the reception sensitivity and so forth.
For example, the Japanese Patent Laid-Open Publication No. HEI 6-53883 discloses the radio selective-calling receiver which eliminates of the bad influence of the switching noise of DC/DC converter as shown in FIG.
3
.
FIG. 3
is a block diagram showing the construction of the conventional radio selective-calling receiver. In
FIG. 3
, the radio selective-calling receiver provides a radio section
501
demodulating received signals, a controller
502
which controls intermittently the operation of the radio section
501
and decodes the demodulated signals from the radio section
501
and outputs the signals controlling on/off of a DC/DC converter
503
, a primary battery
504
supplying power to the radio section
501
and a secondary battery
505
supplying power to the controller
502
. The DC/DC converter
503
is switched on at right before switching on the radio section
501
and converts the power of the primary battery
504
from DC to DC and charges the secondary battery
505
and supplies the power to the controller
502
. An operating section
506
implements the interruption to the controller
502
by the operation of a user.
Next, the operation is explained. The radio section
501
amplifies and demodulates the received signals and supplies the demodulated signals to the controller
502
. The controller
502
decodes the demodulated signals and also controls the radio section
501
and the on/off controlling of the DC/DC converter
503
, and the DC/DC converter
503
is switched on at right before switching on the radio section
501
and charges the secondary battery
505
and supplies the power to the controller
502
. At the time of “off” of the DC/DC converter
503
, the secondary battery
505
supplies the power to the controller
502
. The primary battery
504
supplies the power to the radio section
501
and the DC/DC converter
503
. As mentioned above, the power supply to the controller
502
is implemented by the secondary battery
505
and the charge of the secondary battery
505
is implemented by the DC/DC converter
503
at right before switching on the radio section
501
, therefore the bad influence of the switching noise of the DC/DC converter
503
is possible to be eliminated.
FIG. 4
is a timing chart showing the operation of the radio section
501
and the DC/DC converter
503
of the conventional radio selective-calling receiver using POCSAG (Post Office Code Standardization Advisory group) format.
FIG. 5
is a timing chart showing expanded the “A” part of the timing chart of
FIG. 4
, this shows the change of the output voltage of the secondary battery
505
. As shown in
FIG. 4
, the operation timing of the DC/DC converter
503
is completely different from the operation timing of the radio section
501
, as shown in
FIG. 5
(
2
), the DC/DC converter
503
is switched on for a short period at right before switching on the radio section
501
and implements the charge of the secondary battery
505
and the power supply to the controller
502
, and at the time of “off” of the DC/DC converter
503
, the secondary battery
505
supplies the power to the controller
502
with this charged energy.
The conventional radio selective-calling receiver has the construction stated above. As shown in
FIG. 5
(
3
), at a point “a” the DC/DC converter
503
is switched off and the radio section
501
is switched on and the output voltage of the secondary battery
505
is gradually decreased by the consumption current of the controller
502
. This corresponds to the voltage change showing between points “a” and “b” in
FIG. 5
(
3
). Until again switching on the DC/DC converter
503
, if the consumption current of the controller
502
does not change, the gradually decreasing output voltage of the secondary battery
505
does not become below the minimum operating voltage Vmin of the controller
502
. However, at the case that a user operates the receiver at the point “b”, by the rapid increase of the consumption current of the controller
502
, the output voltage of the secondary battery
505
decreases greatly and becomes below the minimum operating voltage Vmin of the controller
502
at a point “c”, the problem stopping the operation of the controller
502
occurs.
The operation timing of the DC/DC converter
503
is completely different from the operation timing of the radio section
501
, therefore there is a problem that a control signal SW only for the DC/DC converter
503
is needed to be provided.
Moreover, because of the charging time of the secondary battery
505
is short, there is a problem that the restoring time of the terminal voltage of the secondary battery
505
to a sufficient voltage driving the controller
502
takes long.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a radio selective-calling receiver which is capable of supplying a sufficient power to operate a controller and is possible to maintain stable operation of the controller.
To solve the above mentioned problems, the present invention provides a radio section which receives radio signals from the outside by the intermittent operation and demodulates the radio signals, a primary battery supplying the power to said radio section, a controller which decodes said demodulated signals at said radio section and also generates operation timing control signals to make said radio section operate intermittently and outputs said signals to said radio section, a secondary battery supplying the power to said controller, a DC/DC converter which is controlled to the operation
on-operation control by said operation timing control signals from said controller and converts the power of said primary battery from DC to DC and supplies said power to said controller and said secondary battery at the time of the non-operation of said radio section, and an operating section implementing interruption to said controller based on operation input signals.
At the time when the radio section does not operate, the DC/DC converter is switched on by the operation timing control signals from the controller and the power of the primary battery is converted from DC to DC, this DC/DC converted power is supplied to the controller and the secondary battery is charged. With this operation, for the longer non-operation period than the operation period of the radio section, the charge to the secondary battery is able to be implemented and the sufficient energy is able to be stored in the secondary battery and the sufficient power supply to t
Kuntz Curtis
NEC Corporation
Scully Scott Murphy & Presser
Taylor Barry W.
LandOfFree
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