KR100452043B1 - Apparatus and method for increasing discharge time of battery - Google Patents

Abstract

The apparatus for increasing the discharge time of a battery disclosed herein controls connecting power to one of the first and second batteries to an electronic device so that power is supplied, and if the discharge voltage of a battery currently connected to the electronic device When the voltage is lowered, the first and second batteries connected to the electronic device are switched. According to the present invention, when the battery is over-discharged, the discharge time is longer than that of a technique in which nickel-cadmium batteries are connected in parallel.

Description

Apparatus and method for increasing the discharge time of the battery {APPARATUS AND METHOD FOR INCREASING DISCHARGE TIME OF BATTERY}

The present invention relates to a device for supplying power to an electronic device, and more particularly to a device for increasing the discharge time of the battery.

Nickel-cadmium battery is an alkaline storage battery that uses nickel hydroxide at the cathode and cadmium at the cathode. Since then, it has been used in various industrial fields. The discharge capacity of conventional batteries such as sealed lead acid (SLA) and lithium ions can be up to 2C (coulomb), whereas the discharge capacity of nickel-cadmium batteries can be up to 8C.

As described above, the nickel-cadmium battery capable of overdischarging has a problem in that the discharge voltage is drastically lowered during the overdischarge and the discharge time is shortened. For example, when a nickel-cadmium battery of 12 V / 1800 mAH is discharged at a discharge capacity of 6 C (10.8 A), the calculation is about 10 minutes (i.e., ), But when the battery is actually discharged, it can only be used for about 2-4 minutes. This is due to the overdischarge characteristics of the battery.

1 is a graph showing a change in discharge voltage according to discharge capacity when over-discharging a nickel-cadmium battery.

Referring to FIG. 1, it can be seen that the discharge voltage is drastically lowered when the nickel-cadmium battery is discharged at a discharge capacity of 6C than when discharged at a discharge capacity of 1C. Such sudden drop in the discharge voltage is intensified as the discharge capacity increases. When the discharge voltage level is lower than the reference voltage, the electronic device cannot supply the normal voltage even though the battery capacity remains.

It is therefore an object of the present invention to provide an apparatus and method that can increase the discharge time of a battery.

1 is a graph showing a change in discharge voltage according to discharge capacity when over-discharging a nickel-cadmium battery;

2 shows discharge characteristics of a nickel-cadmium battery;

3 shows a schematic configuration of a power supply device according to a preferred embodiment of the present invention for supplying power to an electronic device;

4 is a view showing a configuration according to a preferred embodiment of the battery switching circuit shown in FIG.

5 is a view showing another embodiment of the battery switching circuit shown in FIG. 3; And

6 is a view illustrating a battery switching circuit according to another embodiment of the present invention.

* Description of the main parts of the drawings *

10: power supply 20: electronics

BT1, BT2: Nickel-Cadmium Battery 100, 200, 300: Battery Switching Circuit

RLY: Relay K1: Contact Plate

D1: Diode Q1: NPN Transistor

R1-R5: resistor C1-C3: capacitor

Y1: Crystal Oscillator 101: Microcontroller

201, 202: comparator 203: control logic

301: Timer

(Configuration)

According to a feature of the present invention for achieving the above object, the apparatus for increasing the discharge time of the battery, the first battery, the second battery and the first and second batteries are alternately connected to the electronic power source It includes a battery switching circuit for controlling to supply.

In a preferred embodiment, the battery switching circuit controls the remaining battery to be connected to the electronic device when the discharge voltage of a battery currently connected to the electronic device among the first and second batteries is lower than a reference voltage.

The battery switching circuit may include a microcontroller configured to detect the discharge voltage of a battery currently connected to the electronic device among the first and second batteries, and to reverse a switching control signal when the detected voltage is lower than the reference voltage. Switching means for switching said first and second batteries coupled to said electronic device in response to an inversion of a switching control signal.

In this embodiment, the switching means includes a transistor having an emitter connected to a collector and a ground voltage, a base connected to the switching control signal, and one end connected to a power supply voltage and the other end connected to a collector of the transistor. And a relay for switching any one of the second batteries to be connected to the electronic device.

In a preferred embodiment, the battery switching circuit is a comparator for comparing the discharge voltage and the reference voltage of the battery currently connected to the electronic device of the first and second batteries and outputs a comparison signal as a comparison result, from the comparator Switching control logic for inverting a switching control signal when the comparison signal indicates that the discharge voltage is lower than the reference voltage and switching the first and second batteries connected to the electronic device in response to the inversion of the switching control signal. Switching means.

In a preferred embodiment, the battery switching circuit controls the first and second batteries to be alternately connected to the electronic device every predetermined time.

In this embodiment, the battery switching circuit, the timer for inverting the switching control signal every predetermined time and the switching for switching the first and second batteries connected to the electronic device in response to the inversion of the switching control signal. Means;

In a preferred embodiment, each of said first and second batteries is a nickel-cadmium battery.

According to another aspect of the invention, a method for increasing the discharge time of a battery for supplying power to an electronic device, comprising: connecting any one of the batteries to the electronic device to supply the power, currently the electronic device and Comparing the discharge voltage and the reference voltage of the connected battery and switching the batteries connected to the electronic device when the discharge voltage of the battery currently connected to the electronic becomes lower than the reference voltage.

According to another aspect of the invention, a method for increasing the discharge time of the first and second batteries for supplying power to the electronic device comprises: connecting any one of the first and second batteries to the electronic device; Supplying power and switching the batteries connected to the electronic device at predetermined time intervals.

(Example)

2 is a view showing the discharge characteristics of the nickel-cadmium battery.

Referring to FIG. 2, initially, when the discharge voltage of the nickel-cadmium battery is V0, the discharge voltage of the nickel-cadmium battery gradually decreases as time passes. At this time, as described above, the decrease in the discharge voltage becomes larger as the discharge capacity increases. When the discharge voltage of the nickel-cadmium battery is stopped as the discharge voltage gradually decreases and reaches the reference voltage VREF, the discharge voltage of the battery rises again to a certain level after a certain time. At this time, the increased voltage V1 falls short of the initial discharge voltage V0. By repeating the discharge and forced discharge stop operations of the battery in this manner, the discharge time of the battery can be increased.

3 is a view showing a schematic configuration of a power supply device according to a preferred embodiment of the present invention for supplying power to an electronic device.

Referring to FIG. 3, the power supply device 10 for supplying power to the electronic device 20 includes a first battery BT1, a second battery BT2, and a battery switching circuit 100. The battery switching circuit 100 controls the first and second batteries BT1 and BT2 to be alternately connected to the electronic device 20 to supply power.

4 is a diagram illustrating a configuration of a preferred embodiment of the battery switching circuit 100 illustrated in FIG. 3. Referring to FIG. 4, the battery switching circuit 100 may include a first power terminal V + and a second power terminal V−, a microcontroller 101, a relay RLY, and a diode connected to the electronic device 20. (D1) NPN transistor Q1, resistors R1, R2, and R3, capacitors C1, C2, and crystal oscillator Y1.

The relay RLY connects the contact plate K1 with one end N1 of the first battery BT1 or the second depending on whether current flows between the power supply voltage VCC and the collector of the NPN transistor Q1. Connect to one end N2 of the battery BT2. The diode D1 has an anode connected to the collector of the NPN transistor Q1 and a cathode connected to the power supply voltage. The NPN transistor Q1 has a collector connected to the relay, an emitter connected to the ground voltage, and a base connected to the switching control signal CTRL output from the microcontroller 101 through the resistor R3. The resistors R1 and R2 are sequentially connected in series between the first power supply terminal V + and the ground voltage, and their connection node is connected to the input terminal IN of the microcontroller 101. The capacitor C1 has one end connected to the ground voltage and the other end connected to the clock terminal CLKIN of the microcontroller 101. The capacitor C2 has one end connected to the ground voltage and the other end connected to the clock terminal CLKOUT of the microcontroller 101.

The operation of the battery switching circuit 100 having the configuration as described above is as follows. First, the microcontroller 101 outputs a low level switching control signal CTRL for turning off the NPN transistor Q1. As the NPN transistor Q1 is turned off, the contact plate K1 is connected to one end N1 of the first battery BT1. Therefore, the first battery BT1 supplies power to the electronic device 20. The microcontroller 101 receives the discharge voltage of the first battery BT1 divided by the resistors R1 and R2 and compares the discharge voltage with the reference voltage VREF set therein. If the discharge voltage of the first battery BT1 is greater than the reference voltage VREF, the switching control signal CTRL is maintained as it is. If the discharge voltage of the first battery BT1 is less than the reference voltage VREF, the transistor Q1. Outputs a high level switching control signal (CTRL). As the switching control signal CTRL is inverted from the low level to the high level, the transistor Q1 is turned on, and as a result, the contact plate K1 is connected to one end N2 of the second battery BT2. Thereafter, the electronic device 20 receives power from the second battery BT2. In the same manner, when the discharge voltage of the second battery BT2 divided by the resistors R1 and R2 is lower than the reference voltage VREF, the microcontroller 101 inverts the switching control signal CTRL to invert the transistor. Control to turn off (Q1).

The battery switching circuit 100 controls the first battery BT1 to supply power to the electronic device 20, and as shown in FIG. 2, the discharge voltage of the first battery BT1 is set to the reference voltage (see FIG. 2). When lower than VREF, the voltage recovery time of the first battery BT1 is guaranteed by switching the battery that supplies power to the electronic device 20 to the second battery BT2. Therefore, the discharge time of the batteries BT1 and BT2 may be longer than that of supplying power to the electronic device 20 by connecting the first and second batteries BT1 and BT2 in parallel.

FIG. 5 shows another embodiment of the battery switching circuit shown in FIG. 3. In FIG. 5, the same circuit configuration as the battery switching circuit 100 shown in FIG. 4 is denoted by the same drawing code, and overlapping descriptions are generated.

Referring to FIG. 5, the battery switching circuit 200 includes comparators 201 and 202 and control logic 204 instead of the microcontroller 101 shown in FIG. 4. The non-inverting input terminal (+) of the comparator 201 is connected with the connection node of the resistors R1 and R2, and the inverting pressure terminal (−) is connected with the reference voltage VREF. The non-inverting input terminal (+) of the comparator 202 is connected with the reference voltage VREF, and the inverting pressure terminal (-) is connected with the connection node of the resistors R1 and R2. Each of the comparators 201 and 202 compares the voltages input through the input terminals, and outputs the comparison signals CMP1 and CMP2 as comparison results, respectively. The control logic 203 receives the comparison signals CMP1 and CMP2 output from the comparators 201 and 202 and outputs a switching control signal CTRL for controlling the turn on / off of the transistor Q1.

First, when the switching control signal CTRL from the control logic 203 is at a low level, the contact plate K1 is connected to one end N1 of the first battery BT1. Accordingly, power is supplied to the electronic device 20 by the first battery BT1, and the discharge voltage of the first battery BT1 divided by the resistors R1 and R2 is input to the non-inverting input of the comparator 201. It is input to the terminal (+) and the inverting input terminal (-) of the comparator 202.

When the discharge voltage of the first battery BT1 divided by the resistors R1 and R2 is higher than the reference voltage VREF, the comparator 201 receives the comparison signal CMP1 of the high level (ie, logic '1'). The comparator 202 outputs a comparison signal CMP2 at a low level (ie, logic '0'). The control logic 203 maintains the switching control signal CTRL when the comparison signals CMP1 and COM2 are at the high level and the low level, respectively.

When the discharge voltage of the first battery BT1 divided by the resistors R1 and R2 is lower than the reference voltage VREF, the comparator 201 outputs the low level comparison signal CMP1 and the comparator 202. Outputs a high level comparison signal CMP2. The control logic 203 inverts the switching control signal CTRL when the comparison signals CMP1 and COM2 are at the low level and the high level, respectively. As the switching control signal CTRL is inverted from the low level to the high level, the transistor Q1 is turned on, and as a result, the contact plate K1 is connected to one end N2 of the second battery BT2. Accordingly, power is supplied to the electronic device 20 by the second battery BT2, and the discharge voltage of the second battery BT2 divided by the resistors R1 and R2 is input to the non-inverting input of the comparator 201. It is input to the terminal (+) and the inverting input terminal (-) of the comparator 202.

When the discharge voltage of the second battery BT2 divided by the resistors R1 and R2 is lower than the reference voltage VREF, the comparator 201 outputs the low level comparison signal CMP1 and the comparator 202. Outputs a high level comparison signal CMP2. The control logic 203 inverts the switching control signal CTRL when the comparison signals CMP1 and COM2 are at the low level and the high level, respectively. As the switching control signal CTRL is inverted from the high level to the low level, the transistor Q1 is turned off, and as a result, the contact plate K1 is connected to one end N1 of the first battery BT1.

As described above, the battery switching circuit 200 according to the present invention alternately connects the first and second batteries BT1 and BT2 to the electronic device 20 according to the comparison result of the comparators 201 and 202. . Therefore, the discharge time can be longer than when the batteries BT1 and BT2 are connected to the electronic device 20 in parallel.

6 is a view illustrating a battery switching circuit according to another embodiment of the present invention. Referring to FIG. 6, the battery switching circuit 300 includes a relay RLY, a diode D1, an NPN transistor Q1, resistors R3, R4 and R5, a capacitor C3, and a timer 301. do. The battery switching circuit 300 having such a configuration switches the first and second batteries BT1 and BT2 connected to the electronic device 20 at predetermined times in the timer 301. For example, when the timer 301 outputs the low level switching control signal CTRL, the transistor Q1 is turned off so that the contact plate K1 is connected to one end N1 of the first battery BT1. . Therefore, power is supplied to the electronic device 20 by the first battery BT1. After a predetermined time elapses, the timer 301 inverts the switching control signal CTRL from a low level to a high level. As the switching control signal CTRL is inverted to a high level, the transistor Q1 is turned on, and as a result, the contact plate K1 is connected to one end N2 of the second battery BT2.

The preset time in the timer 301 is set in consideration of the average time at which the discharge voltages of the nickel-cadmium batteries BT1 and BT2 reach the reference voltage VREF.

While the invention has been described using exemplary preferred embodiments, it will be understood that the scope of the invention is not limited to the disclosed embodiments. Rather, the scope of the present invention is intended to include all of the various modifications and similar configurations. Accordingly, the claims should be construed as broadly as possible to cover all such modifications and similar constructions.

According to the present invention, it is possible to increase the discharge time of the nickel-cadmium battery for supplying power to electronic devices such as fire fighting equipment, medical equipment, military, aerospace, automobiles, ships and the like. In particular, when over-discharging the nickel-cadmium battery, the discharge time is longer than that of using the nickel-cadmium batteries connected in parallel.

Claims (10)

In a device powered by electronics: A first battery; A second battery; And A battery switching circuit configured to control the first and second batteries to alternately be connected to the electronic device to supply the power; The battery switching circuit, A microcontroller detecting a discharge voltage of a battery currently connected to the electronic device among the first and second batteries and inverting a switching control signal when the detected voltage is lower than a reference voltage; And And switching means for switching the first and second batteries connected to the electronic device in response to the inversion of the switching control signal. The method of claim 1, The battery switching circuit, And controlling the remaining battery to be connected to the electronic device when the discharge voltage of the battery currently connected to the electronic device among the first and second batteries is lower than a reference voltage. delete The method of claim 2, The switching means, A transistor having a collector, an emitter connected to a ground voltage, and a base connected to the switching control signal; And And a relay, the one end of which is connected to a power supply voltage and the other end of which is connected to the collector of the transistor to switch one of the first and second batteries to be connected to the electronic device. The method of claim 2, The battery switching circuit, A comparator for comparing a discharge voltage and a reference voltage of a battery currently connected to the electronic device among the first and second batteries and outputting a comparison signal as a comparison result; Control logic for inverting a switching control signal when the comparison signal from the comparator indicates that the discharge voltage is lower than the reference voltage; And And switching means for switching the first and second batteries connected to the electronic device in response to the inversion of the switching control signal. The method of claim 1, The battery switching circuit, And controlling the first and second batteries to be alternately connected to the electronic device every predetermined time. The method of claim 6, The battery switching circuit, A timer for inverting a switching control signal every predetermined time; And And switching means for switching the first and second batteries connected to the electronic device in response to the inversion of the switching control signal. The method of claim 1, Wherein each of said first and second batteries is a nickel-cadmium battery. In the method of powering the electronics: Connecting one of the batteries to the electronic device to supply the power; Comparing a discharge voltage and a reference voltage of a battery currently connected to the electronic device; Generating a switching control signal of a first level when a discharge voltage of a battery currently connected to the electronic device is lower than the reference voltage; And Switching the batteries connected to the electronic device in response to the switching control signal of the first level. A method for increasing the discharge time of first and second batteries powering an electronic device: Connecting one of the first and second batteries to the electronic device to supply the power; Inverting the switching control signal at a preset time; And Switching the batteries connected to the electronic device in response to inversion of the switching control signal.