KR19980058758U - LCD display charger - Google Patents

Abstract

The present invention relates to a liquid crystal display charger that can easily inform the state of the current charger and the rechargeable battery by various characters or icons by mounting the liquid crystal module in the charger of the portable telephone. A charger having a rectifying circuit for rectifying the DC into a direct current, an insulation transformer for transforming the rectified DC power, a filter circuit for filtering the transformed DC power, and a transistor switch for interrupting the output of the filter circuit. A microcomputer comprising: a microcomputer for controlling a control signal to the transistor switch, a state of charge current and a charge voltage of a current rechargeable battery, and a built-in analog digital converter; It is composed of a liquid crystal for displaying the output of the micom in various forms of characters or icons, the effect of the present invention is to express the error and the current state of the various chargers on the liquid crystal for the convenience of the user, and also to the micom and the clock It can provide a liquid crystal display charger that can be used as a substitute for the table clock by displaying the time on the liquid crystal display.

Description

LCD display charger

Referring to Figure 1, the configuration of a light-emitting diode charger according to the prior art, the rectifying circuit (1) for rectifying the general home AC power supply; An insulation transformer (2) for transforming the rectified DC power; A filter circuit (3) for filtering the transformed DC power; A transistor switch (4) for interrupting the output of said filter circuit (3); A constant voltage circuit (5) for converting the output of the insulated transformer (2) to a constant voltage; An output field effect transistor (FET) control circuit and an overcurrent protection circuit (6) for controlling the output of the isolation transformer (2) and for protecting the overcurrent; A feedback circuit (7) for feeding back the output of the output FET control circuit overcurrent protection circuit (6); An overvoltage overcurrent protection circuit (8) for receiving the outputs of the filter circuit (3) and the feedback circuit (7) to protect overvoltage and overcurrent; The microcomputer 10 which receives the output of the constant voltage circuit 5 and the output of the overvoltage overcurrent protection circuit 8 and controls the control signal to the transistor switch 8 and the state of charge current and charge voltage of the current rechargeable battery. and; An over temperature protection circuit 9 for protecting the over temperature of the microcomputer 10; It consists of a light emitting diode (LED) for displaying the output of the microcomputer 10.

The operation of the conventional LED charger according to the above configuration is as follows.

As shown in FIG. 1, when general household alternating current is applied, the battery is charged in the rechargeable battery after being converted to direct current in the isolation transformer 2 and the filter circuit 3, and the charging voltage, the charging current, etc. are adjusted by the microcomputer 10. When the full charge is reached, the charging current is cut off using the transistor switch 4 so that no further charging is performed. At this time, the charger displays the color of the light emitting diode (LED) in red when the charger is being charged and turns on the green when charging is completed, thereby displaying the state of completion of charging.

In other words, when household AC power is applied, after full-wave rectification and conversion to DC by the rectifier circuit 1, the AC power induced in the secondary side of the isolation transformer 2 passes through the filter circuit 3 again. , While maintaining the voltage of 8.35V and charging, the current is supplied to the rechargeable battery through the transistor switch (4). At this time, the protection circuits (8, 9) are inserted to prevent overvoltage, overcurrent, and overtemperature. The charging voltage and the charging current are confirmed by (10), and accordingly, the output FET circuit 6 is driven through the feedback circuit 7 to adjust the current to be charged.

On the other hand, when charging starts, the microcomputer 10 displays the color of the light emitting diodes 11 in red until full charge, and when the microcomputer 10 is fully charged afterwards, the microcomputer 10 supplies a current so that no further charging is performed by the transistor switch 4. After blocking, the color of the light emitting diode 11 is changed from red to green to indicate that charging is completed.

In the conventional LED charger, since there is no way to know the state of the rechargeable battery except an external LED, it is impossible to know how much current is currently charged or how much more time is required. However, there is a problem that it is difficult to sufficiently express the values confirmed in the microcomputer such as a malfunction of the rechargeable battery or a malfunction of the charger.

An object of the present invention for solving the above problems is to display the various current states of the charger and the rechargeable battery in the charger of the portable telephone by using a liquid crystal display, so that accurate status diagnosis and easy recognition can be taken in advance. The present invention also relates to a liquid crystal display charger which can avoid an explosion and the like.

1 is a block diagram of a light emitting diode charger according to the prior art.

2 is a block diagram of a liquid crystal display charger according to an embodiment of the present invention.

3 is a charger circuit diagram according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

1 ... rectifier circuit 2 ... isolated transformer

3 ... filter circuit 4 ... transistor switch

5. Constant voltage circuit 6. Output FET control circuit and overcurrent protection circuit

7 ... feedback circuit 8 ... overvoltage overcurrent protection circuit

9 ... Overtemperature protection circuit 20 ... Microcomputer (with analog digital converter)

21 ... LCD

The present invention relates to a liquid crystal display type charger, and more particularly to a liquid crystal display type charger that can easily inform the state of the current charger and the rechargeable battery by various characters or icons by mounting the liquid crystal module in the charger of the portable telephone.

As a means for achieving the above object, the configuration of the present invention, a rectifier circuit for rectifying a general household AC power source to DC, an isolation transformer for transforming the rectified DC power source, filtering the transformed DC power source A charger having a filter circuit and a transistor switch for interrupting the output of said filter circuit;

A microcomputer for controlling a control signal to the transistor switch, a state of charge current and charge voltage of a current rechargeable battery, and a built-in analog digital converter;

The liquid crystal is configured to display the output of the micom in various forms of characters or icons.

Hereinafter, with reference to the accompanying drawings, it will be described an embodiment of the present invention.

As shown in Figure 2, the configuration of the liquid crystal display charger according to an embodiment of the present invention;

A rectifier circuit (1) for rectifying general household AC power with direct current; An insulating transformer (2) for transforming the rectified DC power; A filter circuit (3) for filtering the transformed DC power; A transistor switch (4) for interrupting the output of said filter circuit (3); A constant voltage circuit (5) for converting the output of the insulated transformer (2) to a constant voltage; An output FET control circuit and an overcurrent protection circuit (6) for controlling the output of the isolation transformer (2) and for protecting the overcurrent; A feedback circuit (7) for feeding back the outputs of the output field effect transistor FET control circuit and the overcurrent protection circuit (6); An overvoltage overcurrent protection circuit (8) for receiving the outputs of the filter circuit (3) and the feedback circuit (7) to protect overvoltage and overcurrent; Receives the output of the constant voltage circuit 5 and the output of the overvoltage overcurrent protection circuit 8, and controls the control signal to the transistor switch 8 and the state of the charge current and the charge voltage of the current rechargeable battery, analog analog converter A microcomputer 10 having a built-in; An overtemperature protection circuit (9) for protecting the overtemperature of the microcomputer (20); It consists of a liquid crystal 21 for displaying the output of the microcomputer 20 in various forms of characters or icons.

The operation of the liquid crystal display charger according to the embodiment of the present invention by the above configuration is as follows.

Referring to FIG. 2, the present invention basically includes the configuration of the conventional charger of FIG. 1, and the liquid crystal 21 using proper phrases whenever the current state of the charger identified by the microcomputer in the charger or malfunctions of the charger are used. By displaying on the screen, the user can easily recognize the current state of the charger and the rechargeable battery or errors and handle them. That is, by attaching a liquid crystal display instead of a light emitting diode to display various current states of a conventional charger using a light emitting diode, the current state obtained from an overtemperature protection circuit, an overvoltage and overcurrent protection circuit, a rechargeable battery, and a driving clock of a microcomputer. Expression of the current time, the charge remaining time, etc. can be expressed on the liquid crystal display by the microcomputer.

The circuit diagram of FIG. 3 is currently a mobile phone charger circuit of our company. The voltage of the dot is a voltage for driving the microcomputer and represents a constant voltage of 5 V. The voltage is input to the analog digital converter (ADC) terminal of the microcomputer and this voltage is divided by 1,000 equally (5mV). Will be set. And each Point and The value of the ADC terminal reading the point voltage is calculated as many times the reference voltage, and the difference is compared with the value at full charge, and the comparison value is displayed on the liquid crystal 21.

Meanwhile, above The point is a circuit for measuring the amount of charge current, and converts the current flowing through the resistors R5, R62, and R65 between OPAMP (U3) Nos. 2 and 3 into voltage, since the converted value is very small. 10 times amplification by R6, R7, R8, and R9, and by connecting it to the analog-to-digital converter (ADC) terminal of the microcomputer 20, the current amount of current is measured. And The point is a circuit that measures the voltage of the charger, which can be forcibly stopped by using a switching circuit to prevent the voltage from exceeding 8.4V, which is the full charge voltage of a typical lithium ion battery.

However, in order to implement the above operation, since the microcomputer U7 on the circuit diagram of FIG. 3 is not possible, a microcomputer (eg, Hitachi, Japan Hitachi Co., Ltd.) has a built-in analog / digital converter (ADC) circuit. MICON HD-6473726H) should be used.

On the other hand, by using the micom 20 and the clock to display the time on the screen of the liquid crystal 21 can be used as a table clock.

The effect of the present invention is that the light emitting diode alone has a lot of difficulty in expressing the current state of the charger and the rechargeable battery, and because the current state cannot be represented accurately, by compensating the conventional disadvantage of not knowing the cause of the error when overcharge or error occurs, It is possible to provide a liquid crystal display charger which can be used as a substitute for a table clock by displaying various errors and the current state on the liquid crystal for convenience of the user and displaying the time on the liquid crystal screen using a microcomputer and a clock.

Claims (2)

Rectifier circuit for rectifying general household AC power to DC, Insulation transformer for transforming the rectified DC power, Filter circuit for filtering the transformed DC power, and Transistor for interrupting the output of the sound filter circuit In charger with switch, A microcomputer for controlling a control signal to the transistor switch, a state of charge current and charge voltage of a current rechargeable battery, and a built-in analog digital converter; And a liquid crystal for displaying the output of the micom in various forms of characters or icons. The method according to claim 1, After calculating the current time by using the drive clock of the microcomputer, the liquid crystal display charger, characterized in that it can be used as a clock by displaying on the liquid crystal.