KR980012770A - Constant voltage and constant current regulator when charging battery - Google Patents

Abstract

The present invention prevents overheat and rupture of a battery due to application of a transient voltage during charging of the battery and switches the battery between a constant voltage and a full current mode according to the type of the battery to charge the battery, / Constant voltage regulator. The conventional battery charging device has a problem that it is impossible to use batteries (nickel cadmium, nickel hydride, lithium ion, etc.) which require both a constant voltage and a constant current mode because of the risk of rupture due to excessive charging. In order to solve this problem, the present invention relates to a field effect transistor for performing a switching operation in response to a pulse width modulation signal output from a pulse width modulating means only for outputting a pulse width modulated signal and adjusting a level of an input voltage, A rectification means for rectifying and outputting a voltage output from the other two sides of the transformer; a rectifying means for rectifying the DC voltage output from the rectifying means by a constant voltage / A constant voltage / constant current control means for cutting out the constant voltage / constant current according to the constant current selection mode, a light emitting element for controlling the operation of the pulse width modulation means at a constant voltage / constant current level output from the constant voltage / constant current control means, With a photocoupler. And charge control means for controlling the charge amount of the battery in accordance with the signal output from the constant voltage / constant current control means

Description

Constant voltage and constant current regulator when charging battery

FIG. 1 is an operational circuit diagram of a conventional battery charging apparatus,

FIG. 2 is an output waveform of part A of FIG. 1,

FIG. 3 is a block diagram of a constant voltage and constant current regulator when the battery is charged according to the present invention;

FIG. 4 is a detailed circuit diagram of the constant voltage and constant current regulator when the battery is charged according to the present invention;

FIG. 5 is a configuration diagram of another embodiment of the voltage selector shown in FIG. 4,

FIG. 6 is a configuration diagram of another embodiment of the constant voltage / constant current mode switching unit shown in FIG. 4; FIG.

Description of the Related Art [0002]

100: pulse width modulation section 101: rectification section

102: constant voltage / constant current control unit 102a: constant voltage / constant current mode switching unit

102b: Constant voltage regulator 102c: Constant current regulator

1024: voltage selection unit 103: charge control unit

The present invention relates to a battery charger that prevents overheat and rupture of a battery caused by overcharging and overcharging of a battery, and by switching to a constant voltage and a constant current mode according to the type of the battery, And to a battery constant current / constant voltage regulating device. As shown in FIG. 1, the conventional battery charging apparatus includes a bridge diode (BDI) for full-wave rectifying an input AC power, a pulse width adjusting unit for adjusting a voltage output from the bridge diode (BDI) A field effect transistor 01 which is switched according to the pulse width modulation signal outputted from the modulation section 1 and the pulse width modulation section 1 and a bridge diode BDI2 according to the switching operation of the field effect transistor 01, And a transformer 71 for maintaining the primary input voltage from the secondary side and outputting the same. A rectifying part 2 composed of a diode Dl and a capacitor Cl for outputting a DC voltage as a half voltage of a voltage output from the outside of the transformer 71 and an output voltage outside the rectifying part 2, Variable limiters (VRI) to adjust. And a photocoupler (PC) composed of a light-receiving element PCa emitting light according to the output voltage of the variable resistor VRI and a light-receiving element PCb receiving light. When the AC voltage (110 V / 220 V) is applied to the bridge diode (BDI), the bridge diode (BDI) rectifies the applied AC voltage and outputs the AC voltage. Thereafter, the resistor R1 is outputted to the pulse width modulating unit 1, and the pulse width modulating unit 1 modulates the output voltage with a stable pulse width and outputs the modulated voltage to the field effect transistor 01. Then, the field effect transistor (01) performs a switching operation in accordance with the pulse width modulation signal output from the pulse width modulation section (1). Accordingly, the transformer 71 generates the secondary voltage from the primary input voltage from the bridge diode BDI by the switching operation of the field effect transistor 01, and outputs the secondary voltage to the rectifying unit 2. [ The rectifying unit 2 rectifies the voltage output from the transformer 71 and outputs the smoothed voltage to the output line Veut through the diode D1 and the condenser Cl. At this time, the voltage of the output terminal (Vout) is detected by the resistor (R3) and the variable resistor (VRI) to control the amount of light emission of the light emitting element (PCa) ) Is emitted. Accordingly, the photocoupler (PC) adjusts the pulse width signal of the pulse width modulating unit 1 according to the amount of light emitted, thereby stabilizing the voltage. At this time, the current flowing in the resistor R2 is detected through the field effect transistor 01, and when the current exceeds the predetermined current, the output voltage is short-circuited, so that the pulse of the A portion is generated as shown in FIG. However, the limit point of the pulse width current of the portion A shown in Fig. 2 is different from that of the used portion, and is usually several hundreds mV to 1V. Therefore, the designer has set the value of the resistor (R2) appropriately to minimize the rated error. However, even if the designer sets the resistance value well, the conventional battery charging device can not set the detection point constant, There is a problem that the battery is ruptured due to excessive charging and the lifetime is shortened. Accordingly, it is an object of the present invention to prevent the overheat and rupture of the battery due to the application of the excessive current and voltage during the charging of the battery, A constant voltage regulator and a constant current regulator in which the life and safety of the battery are improved by charging the battery in a constant voltage and constant current mode. According to an aspect of the present invention, there is provided a pulse width modulation apparatus comprising: pulse width modulation means for outputting a pulse width modulation signal to adjust a level of an input voltage; and switching means for performing a switching operation according to a pulse width modulation signal output from the pulse width modulation means. A rectifying means for rectifying and outputting a voltage output from a secondary side of the transformer; and a rectifying means for rectifying and outputting a voltage output from the secondary side of the transformer, A constant voltage / constant current control means for switching a direct current voltage outputted from the rectifying means to a constant voltage / constant current according to a constant voltage / constant current selection mode; and a control means for controlling the pulse width modulation means A photocoupler composed of a light emitting element and a light receiving element for controlling the operation of the constant voltage / Depending on the signal output from the charge will be made of control means for controlling the amount of charge of the battery. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 3 is a block diagram of a constant voltage / constant current switching device according to the present invention. FIG. 4 is a detailed circuit diagram of FIG. 3. As shown in FIG. 3, A field effect transistor (01) for performing a switching operation in response to the pulse width modulation signal output from the pulse width modulation section (100); a field effect transistor And a diode Cl and a capacitor C2 for rectifying and outputting a voltage output from the secondary side of the transformer 71. The transformer 71 is connected to the transformer 71 via a transformer 71, (OP2) OP2 and transistors 02 (03) and 04 for switching the DC voltage output from the rectifying part 171 to a constant voltage / constant current according to the constant voltage / constant current selection mode A constant voltage / constant current control 102 and a constant voltage / A photocoupler PC composed of a light emitting element PCa and a light receiving element PCb for controlling the pulse width modulation signal of the pulse width modulation section 100 in accordance with the voltage / And a control unit 103 for adjusting the charge amount of the pick-up according to the control signal output from the constant voltage / constant current control unit 102. The operation and effect of the present invention constructed as described above will be described with reference to FIG. 3 and FIG. 4. First, to charge the battery, the power (AC110V / 220V) is full-wave rectified and output through the bridge diode (BDI). The pulse width modulating unit 170 modulates the output DC voltage with a stable pulse width and outputs the modulated DC voltage to the field effect transposed sheet 01 through the resistor R2. do. Then, the field effect transistor (01) performs a switching operation in accordance with the pulse width modulation signal output from the pulse width modulation section (100). The trruster 71 outputs the primary input voltage to the secondary side through the switching operation of the field effect transient interrupter 01 and is outputted to the rectifying section 101. The rectifying section 101 is connected to the transformer 71 Is rectified through a diode (B1) and smoothed through a capacitor (Cl) (C2), and a constant voltage regulator (102b) and a constant current regulator (102b) in a constant voltage / constant current controller 102c to the output terminal Vout at the same time. The constant voltage / constant current mode switching unit 102a in the constant voltage / constant current control unit 102 controls the output signals of the constant voltage regulator 102b and the constant current regulator 102c according to an input selection signal. When the selection signal of the constant voltage / constant current mode switching unit 1027 is a "high" input signal, the transistor 02 is turned on to drive the constant voltage regulator 102b. In this case, the differential amplification OPI in the constant voltage regulator 102b is controlled such that a constant reference voltage output from the constant voltage element ICI of the rectifier 101 is lower than the reference voltage through the resistor R4, The divided voltage obtained by the voltage dividing resistors R5 and R7 is compared with each other to output the differential voltage. At this time, the transistor 02 is turned on to output the difference voltage to the light emitting element PCa of the porter coupler PC, and the light emitting element PCa emits the differential voltage outputted. Accordingly, the light receiving element PCb of the photocoupler PC detects the amount of light emitted from the light emitting element PCa to control the pulse width modulation signal of the pulse width modulation section 100. In this case, the transistor Q4 and the resistor R6 of the voltage selection unit 102d are connected in parallel with a resistor R5 connected to the input terminal of the differential amplifying unit OPI, and the transistor Q4 and the resistor R6 are connected in parallel according to the output voltage level selection signal Vont Sector 04 are turned off or turned off, the input voltage of the constant voltage regulator 172b can be varied to output two kinds of voltages. after. The constant voltage / constant current control unit 102 outputs a control signal to the charge control unit 103, and the charge control unit 103 controls the charge amount of the battery according to the output control signal. When the selection signal of the constant voltage / constant current mode switching portion 102a is a "low" input signal, the transistor 02 is turned off and the transistor 03 is turned on to drive the differential amplification OP2. At this time, the differential amplification OP2 in the constant current regulator 102c is controlled such that a constant reference voltage output from the constant voltage element ICI of the rectifier 101 is divided by the divided voltage through the resistor R9 (RIO) Is compared with the voltage output through the resistor R11 divided by resistors R5 and R7 to amplify and output the difference voltage. Then, the transistor 03 is turned on to output the difference voltage to the light emitting element PCa of the photocoupler PC and the light emitting element PCa emits light corresponding to the difference voltage. Accordingly, the light receiving element PCb controls the pulse width modulation signal output from the pulse width modulator 100 according to the output light emission detection amount, thereby adjusting the output current. FIG. 4 is a block diagram illustrating another embodiment of the voltage selector according to the present invention. For example, as shown in FIG. 5, the switcher 04 (05) for switching operation and the two signal lines inputted are composed of a heavy automatic amplifier (OPI). When the output voltage level select symbol Vout Selector of the voltage selection unit is "High ", the transistor Q5 is turned on and the voltage divided through the resistor R13 and the resistor R5 To the differential aeration (OPI). Then, the differential amplifier OPI compares the constant reference voltage Vcc with the voltage divided by the resistors R5, R13 and R7, and amplifies and outputs the other voltage. In addition, when the output voltage select signal Vout Selector of the voltage selection unit is "LOW ", the transistor 05 is turned off and not operated, and the transistor 04 is turned on. That is, when the transistor 04 is turned on and outputs a voltage divided by the resistors R6 and R7 and a voltage through the resistor R5 to the differential amplifying circuit OPI, The divided voltage is compared with a constant reference voltage Vcc through the resistors R6, R7, and R5, and the differential voltage is output. The output voltage Vout can be adjusted because the transistors 04 and 05 are turned on or off according to the output voltage level select signal Vout Selector of the voltage line portion. FIG. 4 is a block diagram of the constant voltage / constant current mode switching unit As another embodiment, if the constant voltage and the constant current are simultaneously implemented in the constant voltage / constant current mode switching unit as shown in FIG. 7, the transistors 02 and 03 are removed and only the diodes D2 and D3 are used to generate the constant voltage / It can be implemented at the same time. In addition, if only the constant voltage is to be implemented in the constant voltage / constant current mode switching section, the diode D3 may be omitted and only the transistor 02 may be driven to realize a constant voltage. On the contrary, if only the constant current is to be implemented in the constant voltage / constant current mode switching section, the constant current can be realized by erasing the diode 02 and driving only the transistor 03. As described above, the output voltage of the battery charging device can be varied depending on the number of cells of the battery, and the output voltage of the battery can be varied depending on the type of the battery (nickel tadmium, nickel hydride, lithium ion, etc.) Therefore, it is possible to maximize the characteristics of the battery and to charge the battery in an optimum state by automatically cutting out the battery in the constant voltage and constant current mode.

Claims (2)

A pulse width modulation unit 100 for outputting a pulse width modulation signal and adjusting an input level thereof, a field effect transistor 01 which is switched according to a pulse width modulation signal output from the pulse width modulation unit 100, A rectifier 71 for rectifying and outputting the voltage output from the other two sides of the transformer 71, a transformer 71 for rectifying the voltage output from the other side of the transformer 71, A constant voltage / constant current control unit 102 for switching the DC voltage output from the rectifying unit 101 to a constant voltage / constant current according to a constant voltage / constant current selection mode, a constant voltage / (PC) for controlling the operation rate of the pulse width modulation unit 100 according to a constant current level and a charge control unit 103 for controlling the charged amount of the battery according to the control signal output from the constant voltage / constant current control unit 102 ) And a constant voltage / constant current regulator for charging the battery. 2. The plasma display apparatus according to claim 1, wherein the constant voltage / constant current control unit (102) comprises a constant voltage / constant current mode switching unit (102a) for switching to a constant voltage / constant current mode and a constant voltage / constant current mode switching unit A constant voltage regulator 102b for generating a voltage for regulating a constant voltage by amplifying a differential voltage between the two voltages, and a constant voltage regulator 102b for regulating the difference voltage between the two voltages input in accordance with the constant current mode switching of the constant voltage / constant current mode switching unit 102a And a voltage selection unit 102d for selecting a level of an output voltage according to the number of battery cells. The battery charger according to claim 1, Constant voltage / constant current regulator. ※ Note: It is disclosed by the contents of the first application.