KR930000302Y1 - Circuit for recharging automatically wireless communication device - Google Patents

Abstract

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Description

Automatic power charging circuit of portable wireless device

1 is a block diagram of the present invention.

2 is a detailed internal circuit diagram of FIG. 1 according to the present invention.

3 is an internal circuit diagram of the DC-DC converter controller U of FIG.

* Explanation of symbols for main parts of the drawings

A1: state of charge detector A2: switch means

A3: DC-DC converter A4: charging current adjusting means

K1: Relay T1: Car Battery Connector

T2: Built-in battery connector T3: Power input terminal for portable wireless device

The present invention is to automatically charge the internal battery of the wireless device by using the internal battery of the wireless device by using the car battery of the same voltage, the automatic power supply of the portable wireless device that is common for charging the battery built in the wireless device It relates to a charging circuit.

When the conventional car mounting and portable wireless device is used in a typical car, the battery is connected to the power source only. Therefore, the portable battery can be charged using a separate AC charger in a place where AC power is supplied. There was a problem that should be.

An object of the present invention is to solve the above problems by adding a charging circuit for charging the internal battery automatically while using a portable wireless device connected to the car battery charging circuit for charging the wireless device used in the car In addition, the present invention provides an automatic power supply charging circuit for a portable wireless device that solves a battery recharging problem that frequently occurs when a wireless device used in a car is used for a portable movement.

In order to achieve the above object, the present invention provides an automotive battery connection terminal, a built-in battery connection terminal, a power input terminal of a portable wireless device, and a power supply of the mobile battery connection terminal and a built-in battery connection terminal for a predetermined time. A charge means detector connected to an input terminal, a switch means connected to the charge state detector and the vehicle battery connection terminal, connected to the charge state detector and the vehicle battery connection terminal, and operated by the charge state detector, connected to the switch means DC-DC converter, and charging current adjusting means connected between the DC-DC converter and the built-in battery connection terminal.

With reference to the accompanying drawings will be described an embodiment of the present invention in detail.

1 is a block diagram of the present invention, T1 is a car battery connection terminal, T2 is a built-in battery connection terminal, T3 is a portable wireless device power input terminal, A1 is a battery charge detector, A2 is a DC switch, A3 represents a DC-DC converter, A4 represents a charge current adjusting circuit, K1 represents a relay, CT1 represents a first relay contact, and CT2 represents a second relay contact.

2 is a detailed internal circuit diagram according to the present invention.

The charging current adjusting circuit A4 is composed of an initial charging current limiting resistor R1 and a current backflow prevention diode D1.

The DC-DC converter (A3) is a parallel switch type DC-DC converter, a coil (L) for making a boosted pulse with the DC-DC converter controller (U), and a rectifier diode (D2) for making a pulse into DC. And smoothing capacitor (C1), current detection resistor (R5) for output current limiting, voltage divider (R2-R3) for output voltage feedback, switching oscillating capacitor (C3), resistor for driving transistor bias (R4), input balance Consists of the utilization capacitor (C2).

3 is an internal circuit diagram of the DC-DC converter controller (U).

An operation of the DC-DC converter A3 and the charging current adjusting circuit A4 will be described with reference to FIGS. 3 and 2 as follows.

When the vehicle battery power is applied to the Vcc terminal of the controller U through the switching transistor of the DC switch A2, a square wave of about 100 kHz is oscillated while the internal osc circuit connected with the external oscillation capacitor C3 operates. The square wave is applied to the base of the driving transistor through an internal control circuit to turn the transistor on and off. Therefore, while the switching transistor connected to the driving transistor is turned on and off, the coil L connected between the collector and the input power supply terminal is turned on and off with the GND terminal to generate a pulse at the collector terminal.

The amplitude of this pulse is higher than the vehicle battery voltage input by the current flowing through the coil L and the switching transistor switching time.

This pulse is rectified and smoothed by the connected rectifier diode D2 and capacitor C1 and converted to DC.

The voltage at the output stage is applied to the comparator inside the DC-DC conversion controller U by a voltage divider circuit composed of resistors R2 and R3, compared to the internal reference voltage (1.25V), and applied to the internal control stage, thereby providing an internal reference voltage. It is input to the internal control stage compared to (1.25V). The control stage outputs the application period of the internal oscillator output signal (100 kHz) applied to the driving transistor in accordance with the input signal, and accordingly changes the ON and OFF periods of the driving and switching transistors so that the resistances (R2-R3) change. Make the set output voltage. Normally the input vehicle battery voltage is 12V, in this case, the DC-DC converter output voltage is set to 15V. Output current detection resistor (R5) is connected to OSC circuit inside controller (U) and is connected to LOSC circuit when over current over set current value flows, and turns off OSC circuit when over current over set current value flows, DC-DC converter OFF the operation.

The DC-DC converter output is input to the charging current adjusting circuit A4, and the initial current charged by the resistor R1 inside the charging current adjusting circuit A4 is limited so that the internal battery connected to the connection terminal T2 is limited. Charge it. Diode D1 is for preventing charge current backflow.

When only the built-in battery is connected to the built-in battery connection terminal (T2) in the portable wireless device, since the current does not flow through the relay (K1), the built-in battery is connected to the power terminal of the portable wireless device through the contact point (CT1) which is always connected. do.

In this case, the additional current consumed to operate the portable radio device is extremely small, such as the number of currents consumed in a high input resistance battery state detector.

When only the car battery is connected to the car battery connection terminal (T1) while the built-in battery of the portable radio device is removed, the current flows through the relay (K1) to connect the contact (CT2) and the contact (CT1) is disconnected. The car battery is connected to the power supply terminal.

In this case, the additional current consumed to operate the portable radio device is supplied from a large-capacity automotive battery by the relay (K1) drive current (about 30 mA).

When the built-in battery of the portable wireless device and the car battery are connected at the same time, the relay K1 is driven using the car battery, and the contact CT2 is connected and the contact CT1 is disconnected, so the car battery is connected to the power terminal of the portable wireless device. Connected.

At the same time, if the built-in battery is not fully charged, the battery charge state detector (A1) saturates the DC switch (A2) and the car battery terminal is connected to the DC-DC converter (A3) input terminal. The reference voltage VEF is applied to the negative terminal of the state of charge detector A1. In this embodiment, the DC switch A2 uses a transistor.

In general, since the voltage of the car battery and the built-in battery is often the same, the DC-DC converter (A3) boosts the power supply voltage input from the car battery to a voltage capable of charging the built-in battery. The output of the DC-DC converter A3 is connected to the charging current adjustment circuit A4 to charge the internal battery while adjusting the charging current.

The present invention is configured as described above and frequently occurs when using the wireless device used in the mobile for the mobile movement by adding a charging circuit for automatically charging the built-in battery while using the conventional portable wireless device connected to the car battery Recharge problem was solved.

Claims (2)

In a power supply circuit of a portable wireless device that can use various power sources, an automotive battery connection terminal (T1), a built-in battery connection terminal (T2), a power input terminal (T3) of the portable wireless device, and the vehicle battery connection terminal ( Circuit switching means (K1, CT1, CT2) for connecting the T1) and the internal battery connection terminal (T2) to the power input terminal (T3) of the portable wireless device for a predetermined time, and the internal battery connection terminal (T2). A switch means A2 connected to the charging state detector A1, the charge state detector A1 and the vehicle battery connection terminal T1 operated by the charge state detector A1, and the switch means. An automatic power supply charging circuit comprising a charging current adjusting means (A4) connected between a DC-DC converter (A3) connected to (A2) and a built-in battery connection terminal (T2). The automatic power supply charging circuit according to claim 1, wherein said switch means (A2) consists of a transistor.