JP3220103B2 - Power supply system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply system provided in a portable cellular phone base station or the like.

[0002]

2. Description of the Related Art In a conventional power supply system for a portable telephone base station apparatus or the like, the output of a backup battery is converted into a voltage through a DC / DC converter, and is used as a power supply. For example, when there are a circuit that operates at a power supply voltage of 10 V DC and a circuit that operates at 5 V, the output voltage of the backup battery is set to 1 in consideration of the conversion efficiency of the DC / DC converter.
About 5V, and 15 by one DC / DC converter
Voltage from V to 10V, and another DC / DC
The voltage was converted from 10 V to 5 V by a converter, and each was used as a power supply.

[0003]

However, in such a conventional power supply system, since the output voltage of the backup battery is once converted by a DC / DC converter and used, the conversion loss due to the voltage conversion is lost. In particular, when a large current flows, the heat generated by the conversion loss increases, and the heat dissipation structure of the base station device itself must be considered. In addition, there is a problem that the heat dissipation structure leads to an increase in the size of the device. Was. Further, since the output voltage of the backup battery must be increased, the external dimensions of the battery increase, and as a result, the external dimensions of the entire base station apparatus also increase.

In the case where power is directly supplied from a backup battery to a specific circuit that consumes a large current in a certain cycle, when the specific circuit is switched from a commercial power supply to a backup battery at a current-on timing, In addition to the occurrence of the voltage drop of the backup battery, the circuit operation becomes unstable, and when the output voltage value of the backup battery is detected at the current-on timing in the same manner as described above, the accurate voltage is obtained due to the voltage drop of the backup battery. There was a problem that the battery output voltage could not be detected. Furthermore, if the output voltage of the backup battery drops below the operating voltage of the specific circuit, the specific circuit will not operate,
On the other hand, the other circuits operating below the voltage continue to operate, and there is a problem that the backup battery is wastefully consumed without functioning as a base station as a whole in the base station apparatus.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problem. In the event of a commercial power failure, an output voltage from a backup battery is directly input to a specific circuit, and a commercial signal is output based on a timing signal from the specific circuit. Switching the backup battery at the time of power failure, detecting and confirming the output voltage value of the backup battery based on the same timing signal, and checking the output voltage of the backup battery for the operation of the specific circuit. The voltage output from the backup battery is cut off when the voltage drops below the set value that is the minimum voltage for backup, so that the size of the backup battery and the base station device can be reduced, the power consumption can be reduced, and the output voltage stability and The purpose is to obtain a power supply system that can improve reliability and use resources effectively. There.

[0006]

In order to achieve the above object, a power supply system according to the first aspect of the present invention includes a power supply unit for converting a commercial power supply voltage to a DC voltage, and a power supply backup when the commercial power supply voltage is cut off. A backup battery to be performed, a DC / DC converter for converting the output voltage of the backup battery to a low voltage, a power failure detector for detecting a power failure of the commercial power supply voltage, the power supply, the backup battery, and the DC / DC. A switching unit for selectively switching and inputting each output voltage of the conversion unit to a specific circuit or another circuit according to a power failure detection result by the power failure detection unit, and providing a power supply voltage used in the specific circuit to the backup battery. as an output voltage substantially the same voltage, at the time of the power failure, and inputs the output voltage of said backup battery to said particular circuit, Serial specific circuit is periodic current on / off
When operating at the timing of
At the timing, the switching unit switches between the commercial power supply and the battery.
Power from one battery to the other
It is something to do .

According to a second aspect of the present invention, in the power supply system, the power supply voltage used in the other circuit and the output voltage of the backup battery are set to the DC / DC.
This is a voltage converted to a low voltage by the converter.

[0008]

According to a third aspect of the present invention, in the power supply system, when the specific circuit operates at a periodic current on / off timing, the voltage detection unit is provided at the current off timing. The output voltage of the backup battery is detected and confirmed.

[0010] The power supply system according to the invention of claim 4, when the output voltage of said voltage battery detection backup of the detection section, falls below the minimum operating voltage value of the specific circuit, said backup The voltage output of the battery is cut off.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a power supply system according to the present invention. In FIG. 1, reference numeral 1 denotes a DC voltage obtained by performing AC / DC conversion of AC 100 V which is a commercial power supply (DC 5 V, DC 10 V, DC 15
V) and supplies it to each unit in the base station apparatus. Reference numeral 2 denotes a control unit that includes a microprocessor, a memory, and the like, and controls the entire base station device.
The control unit 2 generally has an operating power supply voltage of 5V. Reference numeral 3 denotes a transmission / reception unit that performs wireless communication with a slave unit (mobile terminal) (not shown) via the antenna 10, and the specific circuit inside the base station apparatus is referred to as The transmission / reception unit 3 is indicated.

The operating power supply voltage of the transmitting / receiving section 3 is set to 10 V as an example. The transmission / reception unit 3 includes a transmission power amplifier that consumes a large current at the time of transmission. The current is turned on at the time of transmission and turned off at the time of reception. Then, the current ON / OFF timing signal is supplied to the control unit via the signal line 31. 4 monitors the commercial power input to the power supply unit 1 via a signal line 11 and, when the commercial power is cut off, sends out the commercial power cutoff information to the control unit 2 via a signal line 41. It is a power failure detection unit. This power failure detection unit 4 may be provided in the power supply unit 1. 5
Is a charger which receives a DC 15 V voltage (generally higher in potential than the output voltage of the battery to be charged) from the power supply unit 1 and charges a backup battery 6 described later.

Further, this power supply system normally operates using a commercial power supply, and operates with a battery as a backup at the time of a power failure. Therefore, as a charging method, constant charging with a small current is sufficient. The charger 5 is connected to the power supply unit 1.
It may be provided inside. Reference numeral 6 denotes a backup battery for operating the base station apparatus when the commercial power is turned off. In FIG.
It is expressed as 10 VB. Here, B means a battery output. This output voltage is set to the same value as the operating power supply voltage of the transmission / reception unit 3. Reference numeral 7 denotes a DC / DC converter, which performs step-down conversion of a DC input voltage and outputs DC. In this example,
The output voltage from the backup battery 6 is
10V DC to convert to 5V DC voltage used in
(DC10VB) is required at a minimum. Also, as a power supply to the transmitting / receiving unit 3, without passing through the DC / DC converting unit 7,
That is, the output voltage of the backup battery 6 can be directly supplied without performing voltage conversion. This DC / DC conversion unit 7 can be provided in the power supply unit 1.

Reference numeral 8 denotes a switching unit, which is a DC voltage of 5 V (5 V DC) and 10 V (DC 1 V) output from the power supply unit 1.
0V), DC voltage 5 V (DC 5 VB) output from the DC / DC converter 7 and DC voltage 10 V (DC 10 VB) output from the backup battery 6 are switched. DC 10
V. This switching is controlled by the logic of the power failure detection signal input from the power failure detection unit 4 to the control unit 2 and the ON / OFF timing signal input from the transmission / reception unit 3 to the control unit 2. 9 detects a drop in the DC voltage output from the backup battery 6 via a signal line 91,
This is a battery voltage detection unit that is input to the control unit 2 via the signal line 92 as voltage drop information. The battery voltage detecting section 9 can be provided in the control section 2. Further, the control unit 2 having received the voltage drop information controls the switching of the switching unit 8. In addition, generally, the base station apparatus has a line connection unit connected to an exchange and performing wired communication, but is omitted in FIG.

FIG. 2 shows the internal configuration of the switching unit 8 shown in FIG. 1, which is composed of two switches K1 and K2. One of these switches K1 is connected to the power supply unit 1
Voltage 5V (DC5V) from DC and DC / DC converter 7
From the DC voltage of 5 V (DC 5 VB) and outputs it to the control unit 2. This switching operation is performed by a switching control signal from the control unit 2. The other switch K2 is connected to a DC voltage of 10 V (DC 10
V) and a DC voltage of 10 V from the backup battery 6
(DC 10 VB) and outputs it to the transmission / reception unit 3. When there is a commercial power supply, the DC voltage (5 VDC, 10 VDC) from the power supply unit 1 is selected, and when the commercial power supply is cut off, the DC voltage (5 VDC, 10 VDC) from the backup battery 6 is selected. .

Next, the operation will be described with reference to the flowchart of FIG. The simplified type mobile phone base station apparatus according to the present embodiment normally operates on a commercial power supply and performs communication, and the transmitting / receiving unit 3 repeats transmission / reception at a fixed timing (5 ms). The timing signal is always input to the control unit 2 through the signal line 31. Further, during operation with the commercial power supply, the power failure detection unit 4 does not input the commercial power interruption information to the control unit 2 through the signal line 41, so that the control unit 2 uses the switch K of the switching unit 8.
1 and K2 are connected to a DC voltage (DC5V, DC1
0V) is instructed through the signal line 21. That is, the power supply voltage from the power supply unit 1 is supplied to the transmission / reception unit 3.

On the other hand, when the commercial power supply is cut off (step S 1), the power failure detection section 4 outputs the commercial power supply cutoff information to the control section 2 via the signal line 41. Here, the control unit 2
Receives the on / off timing signal from the transmission / reception unit 3 via the signal line 31 and switches the switching signal via the signal line 21 when the on / off timing signal is off and the commercial power supply is determined to be cut off. Input to section 8. For this reason, the switches K1 and K2 in FIG. 2 use the DC voltage (DC5VB, DC10V
The mode is switched to the B) side (step S2). At this point, the base station apparatus is driven by receiving power from the backup battery. As described above, at the current-off reception timing in the transmission / reception unit 3, the voltage drop can be suppressed by switching from the commercial power supply to the backup battery 6, and if the base station apparatus and the slave unit are communicating with each other, Also, unstable operation due to voltage fluctuation can be suppressed. In some cases, the timing of turning off the commercial power supply and the transmission timing of turning on the current in the transmission / reception unit 3 may overlap with each other, so that the power supply unit 1 requires a certain time (at least 5 ms).
As described above, it is necessary to have a mechanism capable of holding the commercial power supply (until the next current-off timing).

When the commercial power is restored while the base station apparatus is being driven by the backup battery 6 as described above, the commercial power cutoff information from the power failure detection unit 4 to the control unit 2 is released. Also at this time, after waiting for the current-off timing signal (step S3), the control unit 2 switches the switches K1 and K2 of the switching unit 8, selects DC5V and DC10V of the DC voltage output from the power supply unit 1, and selects these. Supply to the control unit 2 and the transmitting / receiving unit 3 (Step S
4). If the commercial power supply is not restored, the operation is continued while being driven by the backup battery.

On the other hand, the battery voltage detector 9 monitors the output voltage of the backup battery 6 at regular intervals, and when the output voltage drops to a certain set value, for example, 8 V or less of the power supply voltage at which the transmission / reception unit 3 does not operate. , And outputs the battery output voltage drop information to the control unit 2 through the signal line 92. For this reason, the control unit 2 receives the current-off signal at the reception timing and when the battery output voltage value reaches the set value (step S
5) The further use of the backup battery 6 is stopped, and the switches K1 and K2 of the switching unit 8 are switched to the power supply unit 1 (step S3). This is because the battery output voltage drops below the operating voltage value of the transmission / reception unit 3, and even if only the control unit 2 operates, it does not have a function as a base station device.

Here, the determination of switching from the backup battery 6 to the power supply unit 1 based on the battery output voltage value at the current-off reception timing is based on the following. This is because the output voltage value cannot be determined. At the time of switching of the switching unit 8, since the commercial power is not restored, the operation of the base station device is stopped without power supply. Further, since the backup battery 6 is also separated, further useless battery discharge can be avoided. After this state, when the commercial power supply is restored, since the switches K1 and K2 of the switching unit 8 are connected to the power supply unit 1, the operation using the commercial power supply is restarted.

[0021]

As described above, according to the present invention, the power supply voltage used in the specific circuit is set to be substantially the same as the output voltage of the backup battery, and the output voltage of the backup battery during the power failure is reduced. Input to a specific circuit , wherein the specific circuit has a periodic current on / off timing;
If the current is turned off when
The switching unit is connected to the commercial power supply and the backup battery.
Since the power supply is switched from one side to the other side of the battery, DC /
Reduces the DC converter circuit, miniaturization of the backup battery, and it becomes possible <br/> to reduce the overall size of the apparatus, also the voltage drop at the time of switching of their power
In addition to avoiding the unstable operation of the specific circuit part due to the chip , the power supply voltage used in other circuits
The output voltage of the backup battery is set to the DC / D
By using a voltage converted to a low voltage by the C conversion unit, an effect is obtained that the optimum voltage can be supplied to other circuits while reducing the conversion loss.

According to the invention, the specific circuit is
When operating with periodic current on / off timing
In this case, when the current is turned off,
The output voltage of the backup battery is detected and confirmed.
By doing so, the output voltage of the backup battery can be accurately detected, and further, the output voltage of the backup battery detected by the voltage detector may be lower than the minimum operating voltage value of the specific circuit. In addition, by cutting off the voltage output of the backup battery, it is possible to obtain an effect that unnecessary discharge of the backup battery can be eliminated.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a power supply system according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing details of a switching unit in FIG. 1;

FIG. 3 is a flowchart showing an operation procedure of the power supply system of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Power supply part 2 Control part (other circuits) 3 Transmission / reception part (specific circuit) 4 Power failure detection part 6 Backup battery 7 DC / DC conversion part 8 Switching part 9 Battery voltage detection part

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02J 9/00-11/00 H04B ^7/ 24-7/26 H04Q ^7/ 00-7/04

Claims (4)

(57) [Claims] 1. A power supply unit for converting a commercial power supply voltage to a DC voltage, a backup battery for backing up a power supply when the commercial power supply voltage is cut off, and a DC / DC converter for converting an output voltage of the backup battery to a low voltage. A power outage detection unit that detects a power outage of the commercial power supply voltage; a power supply unit, a backup battery, and a DC / DC.
A switching unit for selectively switching and inputting each output voltage of the conversion unit to a specific circuit or another circuit according to a power failure detection result by the power failure detection unit, wherein a power supply voltage used in the specific circuit is an output of the backup battery. is a voltage substantially the same voltage, at the time of the power failure, the output voltage of the backup battery is input to the particular circuit, the specific circuit at the timing of the periodic current oN / oFF
When operating, at the timing of the current off,
The switching unit includes a commercial power supply and the backup battery.
A power supply system for switching power from one side to the other side . 2. A power supply voltage used in the other circuit, the output voltage of the backup battery being the DC voltage.
2. The power supply system according to claim 1, wherein the voltage is a voltage obtained by converting the voltage to a low voltage by a / DC converter. 3. A battery voltage detecting section for detecting and confirming an output voltage of the backup battery at a timing of the current off when the specific circuit operates at a periodic current on / off timing. The power supply system according to claim 1, further comprising: 4. The voltage output of the backup battery is cut off when the output voltage of the backup battery detected by the voltage detector drops below the minimum operating voltage value of the specific circuit. The power supply system according to claim 3 , wherein: