JPS59182B2 - Battery voltage detection method for selective call receiving device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention measures the voltage of a battery used as a backup power source for a selective call receiving device by using a selective call signal and applying the same load current as in actual use for a short period of time. The present invention relates to a detection method that can determine whether a battery is good or bad.

Various methods have been used as power sources for selective call receiving devices.

Particularly when the above-mentioned receiving devices are installed one by one in private houses for administrative disaster prevention purposes, power is usually supplied from a commercial power supply, and during power outages, power is often supplied to the receiving devices from batteries. When using this type of power supply method, always check that the voltage of the spare battery is higher than the specified voltage, and if the battery voltage falls below the specified voltage, immediately replace the battery with a normal battery. . Conventionally, the battery voltage is constantly measured, and if it falls below a specified voltage, an alarm or display is issued.However, in order to minimize the power loss of the battery during measurement, the current drawn from the battery is I'm trying to minimize it.

On the other hand, since the current drawn from the battery to the load during a power outage is greater than the current during voltage check, the battery voltage applied to the load is lower than the measured battery voltage, and the receiving device does not operate normally and cannot receive the necessary information. There are times when it becomes possible to use force.

In order to solve these problems, the present invention utilizes a selective call signal to extract the same value of current from the battery as in the actual usage state for a short period of time to check the battery voltage, thereby reducing the lifespan of the battery. The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, in which 1 is a receiving antenna, 2 is a receiver that performs high frequency amplification and detection, 3 is a calling signal detection circuit that detects a calling signal, 4 is a rectifying and smoothing circuit, and 5 is a rectifying and smoothing circuit. A power failure detection and active/standby switching circuit, 6 is an opening/closing circuit, 7 is a voltage detection circuit, 8 is a self-holding circuit, 9 is a display or alarm circuit, and 10 and 10' are input terminals.

Next, the operation of the above embodiment will be explained.

First, the power necessary for the selective call receiving device shown in FIG.
It is supplied to each circuit. On the other hand, if the AC power supply is cut off, the power failure detection and active/standby switching circuit 5 operates to detect it and to apply the necessary power to the receiving device from the battery connected to the input terminal 1'. . As a result, even when the AC power is cut off, information sent from the other party can be received without interruption, but the battery voltage of the backup power source is checked in advance, and if the battery is unsuitable for use as a backup power source, a new battery is replaced. I have to replace it. Here, the battery voltage detection method according to the present invention when a plurality of tone signals or a combination thereof is used as a selective call signal will be explained as follows.

In the selective calling method using tone signals, generally Fig. 3a
A selective call signal as shown in FIG.

In Fig. 3a, A, B, C, ..., R are tone signals with different frequencies, and each terminal station receives a predetermined tone signal or a combination thereof. Identify that your station is called. For example, a certain station is A. ! I: Called by the tone signal combination of B,
Other stations are called by a combination of A and C tone signals. The R added at the end of a normal tone signal is a signal for redundancy that is common to all stations, and is used to recover the device from the tone signal reception operation. In the apparatus shown in FIG. 1, a signal received from an antenna 1 is applied to a receiver 2, where it is amplified, frequency converted,
Upon demodulation, a tone signal as shown in FIG. 3a is output. The ringing signal detection circuit 3 identifies that its own station is called from the tone signal, and in the present invention, it also performs switching circuit control particularly for controlling the switching circuit 6 connected to the subsequent stage. A signal is created and output.

An embodiment of the calling signal detection circuit 3 and its operation will be explained with reference to FIGS. 2 and 3. FIG. 2 shows an embodiment of the calling signal detection circuit 3 used in the present invention. In the figure, 30, 31, and 32 are bandpass filters that selectively pass tone signals A, B, and R, respectively; 33, 34,
35 is a detection circuit, 36 and 37 are signal holding circuits, 38 is an AND circuit, and 39 is a 1-shot multivibrator.

3a to 3h are the outputs of the main parts of the circuit shown in the second part, and correspond to the outputs on the line ah indicated in FIG. 2. Now, tone signal A. ! Assuming that the station is called by the combination l:B, the signals from receiver 2 (FIG. 3a) are input to filters 30-32, respectively, and tone signals A, B, and R are selected.

The tone signal A passed through the filter 30 and detected by the detection circuit 33 becomes a rectangular wave as shown in FIG. 3b, and its output is held by the signal holding circuit 36, resulting in the signal shown in FIG. It will be done.

Similarly, the tone signal B that has passed through the filter 31 is
The signal is detected by the detection circuit 34 (Fig. 3c), and the signal is held by the signal holding circuit 3.
Since the output is held at 7, the signal shown in FIG. 3f is obtained. In Figure 3, the explanation is given by ignoring signal delays caused by filters, detection circuits, etc. that occur in the actual equipment, but this is done in order to clarify the correspondence of each signal on the time axis. It is. The outputs of the signal holding circuits 36 and 37 upon reception of the tone signals A and B are input to an AND circuit 38, and a calling signal as shown in FIG. 3g is obtained.

That is, by receiving predetermined tone signals A and B, the station obtains a calling signal and identifies the calling of its own station. Thereafter, when the tone signal R common to each station is received (FIG. 3e), the signal holding circuits 36 and 37 reset their signal holding operations and stop outputting the calling signal.

Further, the calling signal detection circuit 3 shown in FIG. 2 uses the calling signal from the AND circuit to form an opening/closing circuit control signal.

That is, this calling signal is input to the one-shot multi-vibrator 39 to obtain a switching circuit control signal (FIG. 3h) having a predetermined pulse width of T=100 to 500 msec. Returning to FIG. 1, to explain the operation of the device, the switching circuit 6 is closed by the control signal from the calling signal detection circuit 3 formed in the above steps, that is, the switching circuit control signal, and the input terminal 1' The spare battery connected to the voltage detection circuit 7 is connected to the voltage detection circuit 7.

The connection of such a spare battery is only for detecting the voltage of the spare battery output, and the switching circuit 6 is connected for a long time.
It is not preferable to keep the battery closed in terms of power consumption or the lifespan of the spare battery. Therefore, as mentioned above, 1
The switching circuit 6 is closed by a short control pulse of 00 to 500 msec.The voltage detection circuit 7 is provided with a resistance equal to the actual load resistance.

This allows the same amount of load current to flow during voltage detection as that used during normal operation of the terminal station, thus solving one of the problems with the conventional voltage detection method VC. If the voltage detected by this voltage detection circuit 7 is below the specified voltage value, an alarm signal is output, but as mentioned above, the connection between the voltage detection circuit 7 and the spare battery is 100 to 500 ms.
Since the ec is only performed for a short time, this alarm signal is held in the self-holding circuit 8 and sent to the display or alarm circuit 9 to indicate that the battery voltage is below the specified voltage value, that is, when replacing the battery. I'm trying to let you know something. The self-holding state is canceled by replacing the battery with a non-defective one. As explained above, according to the present invention, the voltage of the battery used as a backup power source of the selective call receiving device is measured by using a call signal and applying the same load current as in the actual usage condition for a short period of time to determine whether the battery is good or not. It has the advantage that accurate judgment can be made, and that it has little effect on the battery life because it is a short-time measurement.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention, FIG. 2 shows an embodiment of a calling signal detection circuit, and FIG. 3 shows the output of the main parts of the calling signal detection circuit.

Claims (1)

[Claims] 1. In a selective calling method in which one of a plurality of terminal stations is selectively called, a calling signal detection circuit that detects a local station calling signal included in a received signal and outputs an opening/closing circuit control signal accordingly. , a spare battery, a voltage detection circuit,
It has a self-holding circuit and an opening/closing circuit that opens and closes the connection with the series circuit consisting of the display or alarm circuit, and while the opening/closing circuit is closed, the terminal station is connected to the series circuit connected to the spare battery. When the same amount of load current as that used during normal operation is applied, and the voltage value detected by the voltage detection circuit is below the specified voltage value, the output voltage of the spare battery has decreased below the specified value. A battery voltage detection method for a selective call receiving device, characterized in that it displays or issues an alarm.