JPS6165543A - Cordless telephone set - Google Patents

Abstract

PURPOSE:To prevent the erasure of storage content of a RAM by adopting the constitution that a voltage drop of owner supply voltage is informed to the user by display or the like when the voltage drops to the specified value or below, a timer is started, a cordless circuit section as a load is disconnected from a battery after a prescribed time is elapsed and the RAM is connected succeedingly to the battery. CONSTITUTION:A power switch 3 is turned on normally, a power is applied to the cordless circuit section 2 to apply the function as a cordless telephone set, a voltage of the battery 1 is supplied normally to the RAM3 to hold the storage content of the RAM3. When a voltage drop detection circuit 5 detects that the power supply voltage reaches a prescribed value or below because of the use for a long time, a timer circuit 5 is started and alarm of voltage drop is raised to the user by a display circuit 7. Then a control circuit 8 is operated by an output of the timer circuit 6 as a prescribed time is elapsed to disconnect the battery 1 from a handset circuit 2. Then the RAM3 is energized from the battery 1 succeedingly and the storage content is not lost.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention forms a pair with a connecting device connected to a terminal of a telephone line and has a transmitter/receiver, and forms a wireless line between the connecting device and the above. The present invention relates to a cordless telephone with a built-in battery that allows telephone calls to be made and received from a location a short distance away from a connecting device.

Structure of a conventional example and its problems In Fig. 1, 1 is a battery as a power source for a cordless telephone, 2 is a cordless circuit section consisting of a handset, a transmitter/receiver, etc., and 3 is a final circuit provided attached to the cordless circuit section 2. Cordless circuit unit 2 stores stored information such as calling number and unique number.
R as a volatile memory circuit that inputs and outputs data from and holds it.
AM, 4 is a power switch provided between the battery 1 and the cordless circuit section 2.

When using the cordless telephone with the above configuration, the power switch 4 is turned on to supply power to the cordless circuit section 2, and a predetermined voltage is also applied to the RAM 3 so that the RAM
I have operated it so that the memory contents of 3 are retained.

However, if you forget to turn off the power switch 4 when the power supply type r== of the battery 1 drops after using the handset or after using it for a long time, the voltage of the battery 1 will drop further and the contents of the memory in the RAM 3 will be lost. There was a problem.

Purpose of the Invention The present invention eliminates the drawbacks of the conventional example described above, and also prevents the power supply voltage from dropping due to forgetting to turn off the power switch or talking for a long time.
It is an object of the present invention to provide a cordless telephone in which AM memory contents are not lost.

Structure of the Invention In order to achieve the above object, the present invention notifies the user of this through a display etc. when the power supply voltage falls below a specified value, starts a timer, and after a certain period of time elapses, the cordless circuit unit as a load is activated. while disconnecting from the battery.
By configuring the RAM to continue to be connected to the battery, it is possible to prevent the memory contents of the RAM from disappearing.

Description of examples An embodiment of the present invention will be described below with reference to the drawings.

In Figure 2, 5 is a voltage drop detection circuit, 6 is a timer circuit,
7 is a display circuit including a buzzer, a lamp, etc., 8 is a control circuit, and other symbols similar to those in FIG. 1 represent the same names.

In the above configuration, normally the power switch 3 is turned on, power is supplied to the cordless circuit section 2 to perform the function as a cordless telephone, and the battery 1 is always stored in the RAM 3.
The memory contents of the RAM 3 are held by supplying a voltage of . When the voltage drop detection circuit 5 detects that the power supply voltage has fallen below a predetermined value due to long-term use, etc., the timer circuit 5 is activated and the display circuit 7 issues a voltage drop warning to the user. Thereafter, after a predetermined period of time has elapsed, the control circuit 8 is activated by the output of the timer circuit e, and the battery 1 is disconnected from the handset circuit 2. Therefore, the RAM 3 continues to receive power from the battery 1, and its stored contents are not lost. The display circuit 7 is configured to ring, light up, etc. for a required time and then stop displaying according to instructions from a timer circuit.

As described in detail, according to the present invention, a voltage drop in the battery of a cordless telephone is detected, the user is notified by display, and a timer is activated to remove the load such as the cordless circuit from the battery after a certain period of time has elapsed. Since it is configured to disconnect and prevent the battery from completely discharging, it has the effect of protecting the memory contents of the battery support RAM from being lost due to voltage drop, so various functions such as the last calling number re-call function and speed dial function can be used. When adding additional functions to a cordless telephone, it has the advantage that it can be used without worrying about the memory contents being lost.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a conventional cordless telephone, and FIG. 2 is a block diagram of a cordless telephone according to an embodiment of the present invention. 1...Battery, 2...Cordless circuit section,
3...RAM, 4...power switch, 6...
Voltage drop detection circuit, 6... Timer circuit, γ・
-・Display circuit, 8 ・・Control circuit. Figure 1 Figure 2

Claims (1)

[Claims] A cordless circuit unit that is used for telephone communication with a connecting device connected to a telephone line and is equipped with a handset and a transmitter/receiver, and is driven by a built-in battery, and a cordless circuit unit that is powered by a built-in battery. A RAM that constantly retains stored information from the circuit section, a voltage drop detection circuit that detects a drop in the voltage of the battery, a timer circuit that is activated upon detection of the voltage drop, and a timer circuit that operates for a predetermined period of time based on the output of the timer circuit. A cordless telephone comprising: a control section for disconnecting the battery from the cordless circuit section after a period of time has elapsed; and a display section for notifying a user of the voltage drop through display.