KR0132416B1 - Battery backup control circuit for use in a vehicle's tracking system - Google Patents

Abstract

The present invention relates to a circuit for controlling a backup power supply in the event of a power failure and a breakdown of a main power supply of a stolen vehicle tracking device mounted on a vehicle in an automatic vehicle tracking system.

The backup battery is charged by detecting a voltage level of the backup battery and varying a current according to the level detection of the main power supplied from the vehicle battery power supply terminal.

Digitally converts the voltage of the main power supplied from the vehicle battery power supply to the operating power of the system, and detects the main power supply voltage level by a switch input of the power control terminal and the digitally converted data value and sets the voltage to a predetermined value. The backup power of the backup battery is supplied to the system for a period of time, and when not detected, an alarm signal is generated at the same time as the backup power supply to prevent the system from malfunctioning.

Description

Backup power control circuit of the stolen vehicle tracking device

1 is a circuit diagram according to the present invention.

* Explanation of symbols for main parts of the drawings

10: backup battery 20: level detector

30: variable current charging unit 40: A / D converter

50: control unit 60: timer

70: switching unit 80: reverse power protection unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a back-up power control circuit of a stolen vehicle tracking device. In particular, the present invention relates to controlling a backup power supply when a main power supply of a stolen vehicle tracking device mounted on a vehicle is cut off and a power supply voltage decreases. It is about a circuit.

In general, in an automatic vehicle tracking system, when a user requests the central control station to locate a vehicle, the central control station transmits a signal including a unique address assigned to each vehicle. Then, the onboard equipment mounted on each vehicle receives the signal and compares it with its own address, and if it is the same, it sends a signal indicating its location. The central control center receives the signal and calculates the location of the vehicle and informs the user.

The automated vehicle tracking system as described above is disclosed in detail in 1989 Patent Application No. 6624 and 1990 Patent Application No. 13280 filed by the same applicant as the patent applicant. In addition, the automated vehicle tracking system can track a stolen vehicle. The stolen vehicle tracking device, which is mounted on the vehicle, detects the risk of theft of the vehicle and transmits an emergency message to the central control center informing of the occurrence of an emergency. Then, the central control station receives the emergency message, checks the location of the stolen vehicle, and informs the police station of the information and the location of the stolen vehicle. Theft risk detection here means forcibly attempting to start the vehicle without the key being inserted into the ignition lock cylinder, or if the vehicle power cable or alarm interface cable is cut off or This is to detect when the vehicle is tilted for a certain time due to towing.

As described above, a backup battery was attached to the stolen vehicle tracking device in case the main power supply to the stolen vehicle tracking device was stopped due to the thief removing the vehicle battery. Accordingly, the backup power control circuit of the stolen vehicle tracking device detects when the vehicle battery is cut, connects backup power of the backup transition to the operating power, and generates an alarm signal to transmit an emergency message to the central control center.

On the other hand, in the stolen vehicle tracking device, the backup power supply control circuit as described above has a problem in that a malfunction of the system occurs due to the failure of the backup operation when the main power supply voltage decreases due to the deterioration of the vehicle battery. In addition, there is a problem that an emergency message is transmitted by generating an alarm signal even when the main power line of the vehicle battery is disconnected due to the repair of the vehicle.

Accordingly, an object of the present invention is to provide a backup power control circuit for detecting a backup power control circuit of a stolen vehicle tracking device mounted on a vehicle, which detects when the voltage of the main power supply falls below a set voltage and backs up the power for a set time. In providing.

Another object of the present invention is to provide a backup power control circuit in a backup power control circuit of a stolen vehicle tracking device, which can prevent a malfunction of generating a power backup and an alarm signal when a main power line is disconnected due to repair of a vehicle. have.

Still another object of the present invention is to provide a backup power control circuit in a backup power supply control circuit of a stolen vehicle tracking device that detects the backup power supply voltage when the main power supply is normal and varies the current according to the voltage level to charge the backup battery. Is in.

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

1 is a circuit diagram according to the present invention,

Rechargeable backup battery 10 for backup power supply,

A level detector 20 connected to the backup battery 10 and detecting a voltage level of the backup battery 10;

The main power connected to the vehicle battery power source 101 and the level detector 20 and supplied from the vehicle battery power source 101 to the operating power of the system is varied according to the level detection of the level detector 20. Variable current charging unit 30 for charging the backup battery 10,

An analog-to-digital (A / D) converter 40 connected to the vehicle battery power supply terminal 101 and digitally converting the voltage of the main power supplied from the vehicle battery power supply terminal 101;

Connected to a power control terminal 102 and the A / D converter 40 and controlled by a switch input of the power control terminal 102, and the main power voltage by an output data value of the A / D converter 40; A controller 50 which generates a timer driving signal when the level is detected and falls to a set value, and generates an alarm signal PIS at the same time as the timer driving signal when the level is zero;

A timer 60 connected to the controller 50 and triggered by a timer driving signal of the controller 50 to generate a backup signal for a set time;

The backup battery (10) is connected to the backup battery (10) and the timer (60), while the backup signal is generated by interrupting the backup power supply from the backup battery (10) by the backup signal of the timer (60). A switching unit 70 for supplying backup power as an operating power to the system from 10);

It is connected to the vehicle battery power source 101 and the switching unit 70 and is configured to reverse power protection unit 80 to prevent the backup power is discharged to the vehicle battery power source 101 when the backup power supply. .

The level detector 20 of FIG. 1 is a comparator composed of resistors R1-R3 and an operational amplifier OP, and the resistors R1 and R2 are connected in series between the positive terminal of the backup battery 10 and ground. The connection points of the resistors R1 and R2 are connected to the inverting input terminal (-) of the operational amplifier OP, and the non-inverting input terminal (+) of the operational amplifier OP is connected to the power supply voltage Vcc. A resistor R3 is connected between the non-inverting input terminal + and the output terminal of the operational amplifier OP.

The variable current charging unit 30 includes a diode D1, resistors R4-R7, and transistors Q1-Q2, and includes a diode between the vehicle battery power supply terminal 101 and the positive terminal of the backup battery 10. D1, resistor R4, and transistor Q1 are connected in series. The anode terminal of diode D1 is connected to the vehicle battery power supply terminal 101, and the cathode terminal of transistor Q1 is connected via resistor R4. It is connected to the terminator, the collector terminal of the transistor Q1 is connected to the positive terminal of the backup battery 10, and the resistor R5 is connected between the emitter terminal and the selector terminal of the transistor Q1. In addition, the collector terminal of transistor Q2 is connected to the base terminal of transistor Q1 through a resistor R7, the emitter terminal of transistor Q2 is grounded, and the base terminal of the operational amplifier OP of the level detector 20 is grounded. ) Is connected to ground through resistor R6.

In addition, the control unit 50 is composed of an end gate (G1, G2) and noa gate (G3) and an oragate (G4), the five input terminals of the AND gate (G2) and the no-gate (G3) is an A / D converter (40) is commonly connected to the output terminals (D0-D4) of the two input terminals of the AND gate (G2) two input terminals of the lower third bit output terminal (D2) and A / D converter (40) and Inverts the output of the most significant bit output terminal D4, and two input terminals of the AND gate G1 are connected to the output terminal of the power supply control terminal 102 and the oragate G3 one by one, and the oragate G4 The two input terminals of are connected to the output terminals of the AND gates G1 and G2, one by one.

In addition, the timer 60 includes a resistor R8, a capacitor C1, and a monostable multivibrator M. The positive-edge trigger input terminal A of the monostable multivibrator M is a control unit. Negative-edge trigger input terminal B is connected to the supply voltage Vcc, and terminal T2 is connected to the output terminal of the orifice G4 of the terminal 50 via a resistor R8. It is connected to Vcc and the capacitor C1 is connected between the terminal T1 and the terminal T2.

In addition, the switching unit 70 includes resistors R9-R10 and transistors Q3. The emitter terminal of the transistor Q3 is connected to the positive terminal of the backup battery 10, and the base terminal of the resistor R9. Inverting output terminal of the timer (60) Is connected to the inverting output terminal of the resistor R9 and the timer 60 The resistor R10 is connected between the connection point between the terminals and the emitter terminal of the transistor Q3.

In addition, the reverse power protection unit 80 is composed of a diode (D2-D3), the diode (D2) is the anode terminal is connected to the vehicle battery power supply terminal 101, the cathode terminal is connected to the system, the diode (D3) The anode terminal is connected to the collector terminal of the transistor Q3 of the switching unit 70 and the cathode terminal is connected to the cathode terminal of the diode D2.

Hereinafter, a specific embodiment according to the present invention will be described in detail with reference to the circuit diagram of FIG. 1.

First, the voltage of the main power supplied from the vehicle battery through the vehicle battery power stage 101 of FIG. 1 is supplied to the operating power of the system via the diode D2 and simultaneously converted into digital data by the A / D converter 40. The 5-bit digital data output from the output terminals D0-D5 of the A / D converter 40 is input to the noar gate G3. At the same time, 5 in the state where the lower third bit output terminal D2 and the most significant bit output terminal D4 are inverted among the 5-bit digital data output from the output terminals D0-D5 of the A / D converter 40. Bit data is input to the AND gate G2.

Here, the main power supply voltage by the vehicle battery is typically 13.8V or more in a normal state, and the A / D converter 40 uses the step size of 1V in the description of the present invention, for example. Assume that you use an A / D converter for digital conversion. Then, when the main power voltage drops to about 80% of 11V, that is, about 13.8V of the steady state voltage due to deterioration of the vehicle battery, the three output terminals D0, D0, D0, D4 of the A / D converter 40 D1 and D3 go logic high and the remaining two output terminals D2 and D4 go logic low. As a result, a logic high is generated at the output terminal of the AND gate G2. In addition, when the vehicle battery is separated during theft, and the main power supply voltage becomes 0V, the output terminals DO-D4 of the A / D converter 40 are all logic low. As a result, a logic high is generated at the output terminal of the no-gake G3. At this time, the signal input to the power control terminal 102 is a switch input selected by the user from the outside is a high signal in the normal state. Accordingly, the AND gate G1 is enabled in the normal state to output the logic high signal output from the NOA gate G3 to the OR gate G4 and to output the alarm signal PIS. The alarm signal PIS is applied as an interrupt to a microcomputer (not shown) that controls the system. The microcomputer then transmits an emergency message to the central control center due to the vehicle battery separation when theft is carried out as in the prior art.

At this time, when the vehicle battery is disconnected due to the repair of the vehicle, a logic low signal is input to the power supply control unit 102 by switching the external switch. Accordingly, when the vehicle battery is disconnected due to the repair of the vehicle, the AND gate G1 is disabled to prevent the alarm signal PIS from being generated, thereby preventing malfunction.

On the other hand, the output logic high of the AND gates G1-G2 triggers the monostable multivibrator M at the high edge as a timer driving signal through the orgage G4. Then, the inverting output terminal of the monostable multivibrator (M) Output, i.e., the backup signal transitions from logic high to logic low. Accordingly, the transistor Q3 is turned on so that the backup power of the backup battery 10 is supplied to the operating power of the system via the diode D3. Therefore, due to the deterioration of the vehicle battery, the main power voltage is lower than the normal voltage, and as a result, when the voltage falls below 11V, which is 80% of the normal voltage, or when the vehicle battery is disconnected, the system backs up the power supply. To do.

Therefore, it is possible to prevent the malfunction of the system due to the drop in the main power supply voltage, even when the vehicle battery is separated in theft, it is operated by the backup power supply to detect this and send an emergency message. Here, the power supply backup operation is performed only for a pulse duration of the monostable multivibrator M, that is, a predetermined time set by the external resistor R8 capacitor C1.

Meanwhile, the backup battery 10 is charged through the variable current charging unit 30 when the main power supply voltage is in a normal state, and is charged with a variable current according to the voltage level of the backup battery 10. That is, the voltage level of the backup battery 10 is divided by the resistors R1-R2 and then input to the inverting input terminal (-) of the operational amplifier OP to the non-inverting input terminal (+) as a reference voltage. The voltage level is detected by comparing with the operating power supply voltage Vcc of the input system. When the backup power supply voltage is lower than or equal to the set voltage, the outputs of the operational amplifiers OP become logic high, thereby turning on the transistors Q1-Q2. Accordingly, the main power source charges the backup battery 10 via the diode D1-resistor R4-transistor Q1. On the contrary, when the backup power supply voltage is greater than or equal to the set voltage, the output of the operational amplifier OP becomes a logic low and the transistors Q1-Q2 are turned off so that the main power supply charges the backup battery 10 through the resistor R5. .

At this time, the charging current of the backup battery 10 is set by the resistance value of the resistors R4-R5. For example, set it to charge to 1% of the capacitive current at normal voltage and to 50% of capacitive current when below the set voltage. As a result, when the voltage falls below the set voltage, charging can be performed at a high speed.

Here, the diodes D2-D3 prevent the discharge of the backup battery to the vehicle battery power stage 101 when the backup power is supplied to the system.

On the other hand, the present invention as described above is not limited to the stolen vehicle tracking device, and those skilled in the art can be applied to a mobile communication device or the like using a backup battery.

As described above, the present invention can prevent the malfunction of the system due to the decrease of the main power voltage by backing up the power for the set time when the main power voltage falls below the set voltage, and when the main power line is disconnected due to the repair of the vehicle. There is an advantage that can prevent the malfunction of generating power backup and alarm signal. In addition, by charging the backup battery by varying the current according to the backup power supply voltage level, there is an advantage that can be quickly charged when the backup power supply voltage is greatly reduced.

Claims (1)

A backup power supply control circuit of a stolen vehicle tracking device having a backup battery 10 for controlling power backup, comprising: a level detector 20 for detecting a voltage level of the backup battery 10; The main battery supplied to the system operation power supply from the vehicle battery power supply terminal 101 and connected to the level detection unit 20 and the current is varied according to the level detection of the level detection unit 20 so that the backup battery 10 A variable current charging unit (30) charging the battery, an A / D converter (40) connected to the vehicle battery power supply terminal (101) and digitally converting the voltage of the main power supplied from the vehicle battery power supply terminal (101); And controlled by a switch connected to a power control terminal 102 and the A / D converter 40 and input to the power control terminal 102, and the main power supply being controlled by an output data value of the A / D converter 40. Detect and set the voltage level The controller 50 generates a timer driving signal when the value decreases to a value and generates an alarm signal PIS at the same time as the timer driving signal, and the timer of the controller 50 is connected to the controller 50. A timer 60 that is triggered by a drive signal to generate a backup signal for a set time, and is connected to the backup battery 10 and the timer 60 and is connected to the backup battery 10 by a backup signal of the timer 60. A switching unit 70 for supplying backup power to the system from the backup battery 10 as the operating power while the backup signal is intermittently supplied from the backup battery 10, and the vehicle battery power supply 101; The backup power control circuit is connected to the switching unit (70) and comprises a reverse power protection unit (80) for preventing backup power from being discharged to the vehicle battery power stage (101) when backup power is supplied.