KR100368906B1 - Apparatus charging battery for Cellular Phone - Google Patents

Abstract

According to the present invention, a current path is formed between the secondary coil of the charging transformer and the ground, and is opened and closed according to a predetermined PWM control signal to output a variable pulse width modulation signal, and is operated according to opening and closing of the PWM switching means. A photocoupler for controlling the power applied to the primary coil of the transformer, switching means for intermittently controlling the power induced by the secondary coil of the transformer to be controlled within a set range by operating according to whether the photocoupler is opened or closed; Power and charge applied to the battery with voltages across the first resistor connected in series between the first terminal and the second terminal, and through the fourth and fifth resistors connected between the fourth terminal of the charging port and the predetermined detection control terminal, respectively. A battery power monitoring unit which detects and monitors a state and a capacity of the battery, and a voltage between both ends of the first resistor and a preset reference After comparing the voltages, a PWM control signal having a variable frequency was generated according to the comparison result to control the PWM switching means, and the capacity, mounting state, and full charge related signal of the battery from the second and third terminals of the charging port. It is equipped with a system controller to control various devices, and by using a PWM switching method instead of controlling the primary power supply using an operational amplifier and a plurality of comparators, thereby simplifying the internal circuit of the charger significantly The present invention relates to an AC charging device for a battery for a mobile terminal, which reduces the productivity and reduces the defective rate.

Description

AC charging device for battery for mobile terminal {Apparatus charging battery for Cellular Phone}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charger for charging a battery, and in particular, to control a primary power supply using a conventional operational amplifier and a plurality of comparison circuits, using a pulse width modulation (PWM) signal source built into a controller. The present invention relates to an AC charging device for a battery for a mobile terminal, which is configured to control a primary power supply, thereby reducing parts of a charger and reducing production defects.

The conventional battery charger adopts a linear method for controlling the primary side AC power using the operational amplifier 50 for controlling the current / voltage and the plurality of comparators 55 and 60 as shown in FIG. 1. .

The battery charging device includes a charging port 10 including a power supply terminal 1 for monitoring a battery, a monitoring terminal 2 and 3 and a grounding terminal 4, and an AC power input from the outside for a predetermined noise prevention. AC / DC converter 20 for full-wave rectifying and converting into high voltage DC power through line filter NF, bridge diode BD and capacitor C1, first transformer T1 for battery charging and control agent 2 having a transformer T2 and a switch circuit 35, the switching element M1 of the switch circuit 35 is turned on / off in accordance with a switch control signal input from the outside and thus the first and second transistors T1. And a low voltage switching switch unit 30 which induces a high voltage DC power applied to the primary coil of T2 to low pressure and a power induced by the secondary coil of the first transformer T1. L, C filter (L, C2, C3) to smooth and output low-voltage DC power In addition, it is composed of a DC low voltage output unit 40 including a monitoring circuit for monitoring the amount of current applied to the battery by a capacitor (C4) and a resistor (R1) connected in series between the one end and the ground of the secondary coil, respectively.

In addition, the low-pass operational amplifier for detecting the current applied to both ends of the resistor (R1) of the current monitoring circuit (C4, R1) of the DC low voltage output unit 40 is received by the inverting terminal (-) and amplified through a closed loop. (50) and the output current of the operational amplifier 50 is provided to the inverting terminal (-), and a predetermined control signal is provided to the non-inverting terminal (+) and compared, and then the low voltage switching switch unit 30 Receiving a first comparator 55 for outputting a current control signal for controlling the amount of primary current applied to the primary side and a voltage applied to the power supply terminal 1 of the charging port 10 as an inverting terminal (-); In addition, a predetermined control voltage, which is preset, is supplied to the non-inverting terminal (+), and then a voltage control signal for controlling the primary side voltage applied to the low voltage switching switch unit 30 is compared with that of the first comparator 55. The second comparator 60 outputs to the output stage.

In addition, between the secondary coil of the first transformer (T1) of the low voltage switching switch unit 30 and the output terminal of the first comparator 55 is installed in the forward direction to generate an optical signal for controlling the switch in accordance with the current flow and the light emission signal And a photo coupler 65 for controlling the power applied to the low voltage switching switch unit 30 by opening and closing the switching element M1 of the switch circuit 35 and the low voltage DC output unit 40. The charging switch unit 70 is installed between the power supply terminals 1 of the charging port 10 to cut off the supply power according to a predetermined control signal when the battery mounted in the charging port 10 is fully charged. The display unit 80 includes a plurality of light emitting devices for indicating whether the battery is mounted, the mounting error, and the full charge state according to the control signal, and the capacity ID of the battery mounted in the charging port 10 and the battery are applied to the battery. Check the voltage status and battery charge The system controller 90 controls the charging switch unit 70, the first comparator 55, and the general systems 60 and 80.

Looking at the operation of the charger configured as described above is as follows.

When the battery is mounted on the charging port 10, the DC power is supplied to the battery through the low voltage switching switch unit 30, the DC low voltage output unit 40, the charging switch unit 70, and the current passages of the charging port 10. do.

On the other hand, the voltage applied to both ends of the resistor (R1) provided in the DC low voltage output unit 40 is supplied to the inverting terminal (-) of the current detection operational amplifier 50 and amplified, and then the first comparator 55 for current control. The first comparator 55 compares the voltage inputted to the inverting terminal (-) with a preset reference voltage inputted to the non-inverting terminal (+) and supplies a signal according to the result. It outputs to control the operation of the photocoupler (65).

Accordingly, the switching element M1 forming the closed loop with the primary power supply controls the current applied to the primary coils of the first and second transformers T1 and T2 in response to whether the photocoupler 65 is opened or closed. The amount of current induced in the secondary coil is controlled.

In addition, the second comparator 60 for controlling the voltage receives the voltage applied to the power supply terminal 1 of the charging port 10 as the inverting terminal (-) and receives the constant fixed voltage as the non-inverting terminal (+) and compares the result. The switching device M1 for outputting the voltage according to the result of the comparison to the photocoupler 65 to determine the opening and closing of the photocoupler 65, and forming a closed loop with the primary power supply is determined whether the photocoupler 65 is open or closed. In response, the voltage applied to the primary coils of the first and second transformers T1 and T2 is controlled to control the voltage induced in the secondary coil.

The conventional technique of controlling the primary side power supply of the charger in the manner as described above uses the operational amplifier 50 and the plurality of comparators 55 and 60 as a means for controlling the current and voltage of the charger 10. As well as the design is complicated, there was a problem that the defects and productivity of the parts are reduced accordingly.

Accordingly, an object of the present invention is to implement the control of the primary power by using a pulse width modulation (PWM) signal source built into the controller to control the primary power using a conventional operational amplifier and a plurality of comparison circuits, The present invention provides an AC charging device for a battery for a mobile terminal which reduces the parts of a charger and improves productivity by reducing production defects.

The technical means of the present invention for achieving the above object is a power state in which the battery is charged or supplied to the battery through the first to fourth terminals of the charging port after converting the alternating current into a low voltage direct current through the rectifying circuit and the charging transformer An alternating current (AC) charger comprising: a PWM switching means configured to form a current path between a secondary coil of the transformer and a ground, and to be opened and closed according to a predetermined PWM control signal to output a variable pulse width modulation signal; A photocoupler operated according to opening and closing of the PWM switching means to control power applied to the primary coil of the transformer; Switching means installed in a current path of a primary coil of the transformer to form a closed loop, and operated according to whether the photocoupler is opened or closed to control power induced in the secondary coil of the transformer to regulate within a setting range; A charging switch unit disposed between the secondary coil of the transformer and the first terminal of the charging port to cut off power supplied to the battery according to a predetermined full charge control signal; Applied to the battery with voltages across the first resistor connected in series between the first terminal and the second terminal of the charging port and through the fourth and fifth resistors connected between the fourth terminal of the charging port and the predetermined detection control terminal, respectively. Battery power monitoring unit for detecting and monitoring the power and the state of charge and the capacity of the battery; And comparing the voltages of both ends of the first resistor with a preset reference voltage and generating a PWM control signal having a variable frequency according to the comparison result to control the PWM switching means, and the second terminal and the third terminal of the charging port. It is characterized in that it comprises a system controller for controlling a variety of devices by receiving the capacity and mounting state of the battery and a full charge-related signal from the terminal.

1 is a circuit diagram showing a conventional AC charging apparatus,

2 is a view showing the appearance of a typical charger and the mounting state of the battery,

3 is a circuit diagram showing an AC charging apparatus according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

110: AC / DC conversion unit 120: low voltage switching switch unit

130: DC low voltage output unit 140: PWM switch unit

150: photo coupler 160: charging switch unit

170: battery power monitoring unit 180: alarm signal generating unit

190: system controller ① to ④: charging port

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

2 is a view showing a mounting state of a typical charger and a battery, Figure 2a shows the appearance of the charger, Figure 2b shows the mounting state of the battery.

The charger is externally mounted to the removable device 100 for mounting the battery of the mobile terminal, and installed on one side of the removable device 100 and electrically coupled with the battery, and supply power to the battery or supply voltage and capacity of the battery. And a plurality of terminals (1) to (4) for monitoring the signal, a display unit 181 for indicating a charging state and a mounting error of the battery, and a buzzer 185 for alarming the charging state and a mounting error of the battery.

The internal circuit of the charger having the external shape as described above, the power source for generating a secondary voltage of the constant voltage and constant current from the AC power, and based on this, whether the battery is inserted, the capacity (ID) and the state of charge of the battery, etc. It can be broadly divided into a control part for controlling, and a detailed configuration of the present invention for a charger having the above structure will be described with reference to FIG. 3 below.

3 is a circuit diagram showing an AC charging apparatus according to an embodiment of the present invention, the charging port (① ~ ④), AC / DC conversion unit 110, low voltage switching switch unit 120, DC low voltage output unit 130 ), A PWM switch unit 140, a photo coupler 150, a charging switch unit 160, a battery power monitoring unit 170, an alarm signal generator 180, and a system controller 190.

The charging ports (1) to (4) comprise a terminal for applying charging power to the battery and a plurality of terminals for detecting the mounting, type, and state of the battery, and the AC / DC converter 110 is input from the outside. AC power is rectified and rectified by a predetermined noise prevention line filter (NF), bridge diode (BD) and capacitor (C1) to convert to a high-voltage DC power, the low voltage switching switch unit 120 is charged A first transformer T1 for control, a second transformer T2 for control power supply, and a switch circuit 125, and the switching element MN1 of the switch circuit 125 is turned on according to a switch control signal input from the outside. It is configured to secondaryly induce high voltage DC power applied to the primary coils of the plurality of transformers T1 and T2 to low pressure, and the DC low voltage output unit 130 is turned on / off of the first transformer T1. Secondary coil Receiving offer the organic power is constituted by a smooth through a predetermined L, C filter (L, C2, C3) so as to output a direct-current power supply with a low voltage.

In addition, the PWM switch 140 has a current path formed between one end of the secondary coil of the first transformer T1 and the ground, and is opened and closed according to a predetermined PWM control signal to be applied to the low voltage switching switch 120. The photocoupler 150 is installed in the forward direction between the secondary coil of the first transformer T1 of the low voltage switching switch unit 120 and the output terminal of the PWM switch unit 140 in accordance with the current flow. It is configured to generate an optical signal for control of the switch and to be connected in accordance with the light emission signal to open and close the switching element MN1 of the switch circuit 125 to open and close the power applied to the primary coils of the transformers T1 and T2. .

In addition, the charging switch unit 160 is installed between the low voltage DC output unit 130 and the power supply terminal (①) of the charging port, and when the battery BT mounted in the charging port is fully charged, supply power according to a predetermined control signal. It is composed of a plurality of switching elements (Q2, Q3) for blocking, and the battery power monitoring unit 170 is installed between the output terminal of the charging switch unit 160 and the battery BT and the first terminal ① of the charging port and A current which detects a voltage between both ends of the first resistor R1 connected in series between the second terminals ② and detects a voltage applied to the second terminal ② of the charging port through the third resistor R3; It consists of voltage supervisors.

In addition, the alarm signal generation unit 180 is turned on according to a predetermined control signal to the plurality of light emitting elements 181 and the buzzer 185 which display or alert whether the battery BT is mounted, the mounting error, and the full charge state. The system controller 190 controls the opening and closing of the PWM switch unit 140 by comparing the current applied to the battery BT with the voltages detected through both ends of the first resistor R1. The amount of current supplied to the primary coil of the first transformer T1 is constantly controlled, and the voltage applied to the battery BT is detected through the third resistor R3 to control the opening and closing of the PWM switch 140. The voltage applied to the primary coil of the first transformer T1 is constantly controlled, and the capacity ID of the battery BT mounted on the charging port, the voltage state applied to the battery, and the state of charge of the battery are detected. To control the charging switch unit 160 and the general system 180 It is configured.

In addition, the battery voltage monitor 170 may include a first resistor R1 connected in series between the first terminal ① and the second terminal ② of the charging port, which is an output terminal of the charging switch unit 160, and the charging port. The second resistor R2 provided in series between the first terminal ① and the first A / D terminal ADC1 of the system controller 190 and the second terminal of the charging port coupled with the + electrode of the battery BT. (2) and the third resistor R3 provided between the second A / D terminal ADC2 of the system controller 190, the fourth terminal ④ of the charging port coupled with the negative electrode of the battery BT, and the system. It is composed of fourth and fifth resistors R4 and R5 which are provided in series between the third A / D terminals ADC3 of the controller 190 and detect the capacity ID of the battery.

Looking at the operation of the present invention configured as described above are as follows.

The AC power input through the input plug is rectified by the bridge diode BD and the capacitor C1 of the AC / DC converter 110 and converted into a high voltage DC power.

In addition, the AC / DC converter 110 is provided with various elements for preventing overcurrent, protecting a circuit from a surge AC power supply, or preventing noise input from an external system.

The primary coils of the first and second transformers T1 and T2 convert the DC power output through the bridge diode BD into a secondary coil and convert the DC power to a low voltage DC power. The transformers T1 and T2 have a closed loop through the current path of the switching element MN1 provided in the switch circuit 125 to open and close the power supply according to the PWM switching of the switching element 125.

The PWM signal induced to the secondary coil of the first transformer T1 is rectified to low voltage through the smoothing circuits L, C2, and C3 of the DC low voltage output unit 130, and the battery BT becomes full charged. Until the current is supplied to the battery BT through the first terminal (①) and the second terminal (②) of the charging port through the current path of the charging switch unit 160 is continuously turned on.

On the other hand, the response of the switching device MN1 of the switch circuit 125 is determined according to the operation of the photocoupler 150. When the transistor of the photocoupler 150 is turned on, the switching device MN1 When turned off to cut off the power supplied to the primary coil, when the photocoupler 150 is closed (off) the switching element (MN1) is turned on to supply power to the primary coil.

In addition, the photocoupler 150 is determined according to whether the PWM switch unit 140 is opened or closed. When the pulse width applied to the PWM switch unit 140 is variously modulated, the primary side of the plurality of transformers T1 and T2 is provided. Various amounts of current and voltage applied to the coil can be controlled.

Accordingly, the photocoupler 150 is operated according to the power state induced by the secondary coil of the first transformer T1 and the pulse output from the PWM switch unit 140 to switch the switching element MN1 of the switch circuit 125. By controlling the power supplied to the primary coil by opening and closing the control panel, constant power can be induced to the secondary coil.

In addition, the diodes used in the low voltage switching switch 120 and the DC low voltage output unit 130 are most preferably using a Schottky diode having a fast switching speed.

As described above, it is possible to control the photocoupler 150 and the switch circuit 125 to adjust the power induced to the secondary coil of the first transformer T1 by the PWM control signal of the system controller 190. The controller 190 adjusts the pulse width output to the PWM switch unit 140 based on the power information detected by the battery power monitoring unit 170.

The system controller 190 is an 8-bit controller for controlling a charging system and has an input / output port, a timer, and an analog / digital converter.

The current flowing to the secondary coil of the first transformer T1 is applied to the battery BT through the first terminal ① and the first resistor R1 and the second terminal ② of the charging port. The controller 190 detects a voltage applied to both ends of the first resistor R1 through the second resistor R2 and the third resistor R3 after detecting the current flowing through the secondary coil through the ADC1 and ADC2 terminals. Compared with the set reference voltage and according to the result of the comparison, that is, if the detected voltage is higher than the preset voltage, output 'high' signal in the low state, and if the detected voltage is lower than the preset voltage, By outputting a predetermined PWM control signal in a manner of outputting a 'low' signal to control the on / off of the PWM switch unit 140, the voltage difference between the both ends of the first resistor (R1) is adjusted to the set reference value. .

In addition, a third resistor R3 is connected in series between the second terminal ② of the charging port and the ADC2 terminal of the system controller. The resistor R3 detects a voltage applied to the secondary coil. PWM control by outputting 'high' signal when the detected voltage exceeds 0.005V more than the preset voltage according to the comparison result after comparing with reference voltage of By outputting a signal to control the on and off of the PWM switch unit 140, it is possible to supply a constant voltage to the battery.

Therefore, the system controller 190 should use a controller having a resolution in units of 0.005V. If the voltage detected through both ends of the first resistor R1 is greater than or equal to a preset voltage, the voltage control is given priority. If the voltage detected through the resistor R3 is less than or equal to the preset voltage, current control is given priority.

The system controller 190 generates an appropriate PWM signal according to the power information detected through the first resistor R1 and the third resistor R3 to generate the PWM switch unit 140 and the photocoupler 150 and The switching element MN1 is switched at a predetermined variable frequency to control the power of the secondary coil induced through the first and second transformers T1 and T2.

In addition, if the power information detected through the third resistor R3 is information indicating that the battery BT is fully charged, the system controller 190 sends a 'low' signal to the switching element Q2 of the charging switch unit 160. Outputs to cut off the power applied to the battery (BT).

On the other hand, the system controller 190 is driven to be supplied by a constant power supply (VDD) after down the power induced in the secondary coil of the second transformer (T2) to a predetermined voltage through a predetermined constant voltage power supply circuit (not shown). Consists of.

In addition, the system controller 190 controls the overall system 140 and 160 by detecting the capacity, the mounting state, and the charging state of the battery through the second terminal ② and the third terminal ③ of the charging port. By controlling the plurality of light emitting elements 181 and the buzzer 185 of the alarm signal generating unit 180, an alarm signal is generated when the battery is in a bad mounting state or is fully charged, and thus it is possible to immediately detect and confirm audible and unnecessary. This can prevent current leakage.

Therefore, in the present invention, instead of controlling the primary power supply of the charger by using an operational amplifier and a plurality of comparators, by using a PWM switching method and a resistance monitoring circuit, the internal circuit of the charger can be simplified to greatly reduce the parts used. In addition, there is an advantage of improving productivity, reducing defective rate, and reducing production costs.

In addition, by attaching a plurality of light emitting elements as well as a buzzer on the display unit, the battery mounting error and the state of full charge can be visually and audibly alerted, so that the charging information can be delivered more accurately and quickly, thereby increasing convenience and unnecessary. There is an effect that can prevent the waste of current by preventing the leakage of current.

Claims (6)

In the AC charger for converting the AC into a low voltage direct current through the rectifier circuit and the charging transformer and charging the battery through the first to fourth terminals of the charging port or monitoring the power supply state supplied to the battery, PWM switching means for forming a current path between the secondary coil of the transformer and ground and open and close according to a predetermined PWM control signal to output a variable pulse width modulation signal; A photocoupler operated according to opening and closing of the PWM switching means to control power applied to the primary coil of the transformer; Switching means installed in a current path of a primary coil of the transformer to form a closed loop, and operated according to whether the photocoupler is opened or closed to control power induced in the secondary coil of the transformer to regulate within a setting range; A charging switch unit installed between the secondary coil of the transformer and the first terminal of the charging port to cut off power supplied to the battery according to a predetermined full charge control signal; Applied to the battery with voltages across the first resistor connected in series between the first terminal and the second terminal of the charging port and through the fourth and fifth resistors connected between the fourth terminal of the charging port and the predetermined detection control terminal, respectively. Battery power monitoring unit for detecting and monitoring the power and the state of charge and the capacity of the battery; And After comparing the voltage between the both ends of the first resistor and a predetermined reference voltage and generating a PWM control signal of a variable frequency in accordance with the comparison result to control the PWM switching means and the second terminal and the third terminal of the charging port And a system controller for controlling various devices by receiving a battery capacity, a mounting state, and a full charge-related signal from the battery. The method of claim 1, The system controller, AC charging device for a battery for a mobile terminal, characterized in that configured to control the alarm generating means for visually and audible alarm in accordance with the information on the mounting error and the full charge state of the battery detected by the battery power monitoring unit. The method of claim 1, The battery voltage monitoring unit, A first resistor connected in series between the first terminal and the second terminal of the charging port; A second resistor disposed in series between the first terminal of the charging port and the first A / D conversion terminal of the system controller; A third resistor provided between the second terminal of the charging port and the second A / D conversion terminal of the system controller; And A fourth and fifth resistors installed in series between the fourth terminal of the charging port and the third A / D conversion terminal of the system controller to detect power, mounting state, and capacity applied to the battery, respectively; AC charging device for terminal batteries. The method according to claim 1 or 3, The system controller, And a voltage control PWM signal is output when the voltage detected through both ends of the first resistor is higher than a preset reference voltage. The method according to claim 1 or 3, The system controller, And a current control PWM signal is output when the voltage detected by the second resistor is lower than a preset voltage. The method according to claim 1 or 3, The system controller, At the initial stage of charging the battery, the voltage induced across the secondary coil of the transformer is controlled by using the voltage across the first resistor, and the voltage detected by the second resistor is used from the time when the battery is fully charged. AC charging device for a battery for a mobile terminal, characterized in that for controlling the voltage induced by the secondary coil of the transformer.