KR20080018546A - Apparatus for detecting battery voltage of battery equalizer on large vehicle - Google Patents

Abstract

A battery voltage detecting device of a battery equalizer for a large vehicle is provided to prevent dark current by restricting power of first and second batteries from being discharged through a dummy resistor and four sensing resistors by cutting off a gap among the first and second batteries and a sensing unit, if an engine stops. A battery voltage detecting device of a battery equalizer(20) for a large vehicle detects voltage of first and second batteries(B1,B2) connected in series, through the divided voltage of sensing resistors(RS1~RS4) by a sensing unit(30), and has a switching unit(40) installed among the first and second batteries and the sensing unit and intermitted by an ignition signal(IG) according to the starting state of the vehicle. The switching unit connects the first and second batteries and the sensing unit to each other if the ignition signal is turned on and cuts off the first and second batteries and the sensing unit if the ignition signal is turned off.

Description

Battery Voltage Sensing Device for Battery Equalizer for Large Vehicles {APPARATUS FOR DETECTING BATTERY VOLTAGE OF BATTERY EQUALIZER ON LARGE VEHICLE}

1 is a circuit diagram illustrating a battery voltage sensing device of a battery equalizer for a large vehicle according to the prior art.

2 is a circuit diagram illustrating a battery voltage sensing device of a battery equalizer for a large vehicle according to an exemplary embodiment of the present invention.

   -Explanation of symbols for the main parts of the drawings-

10: Alternator

20: battery equalizer

30: detector

40: switching unit

The present invention relates to a battery voltage sensing device of a battery equalizer for a large vehicle, and more particularly, to convert the 24V power to 12V so as to use 12V power independently in a large vehicle. The present invention relates to a battery voltage sensing device of a commercial vehicle battery equalizer capable of removing a dark current generated when a vehicle is stopped by a dummy resistor used to sense a voltage.

Typically, large vehicles use a 24V system with two 12V batteries in series. Therefore, if you want to use a 12V power supply independently, it is damaged by the unbalance of the two batteries, so the battery equalizer is used to prevent this and to provide a stable 12V power supply. In other words, such a battery equalizer is a DC / DC converter that converts a 24V supply into a 12V supply.

In order to supply stable power in the battery equalizer, the voltage of the battery is sensed by using a resistor for controlling the DC / DC converter and processing various analog signals.

1 is a circuit diagram illustrating a battery voltage sensing device of a general vehicle battery equalizer for a large vehicle.

As shown here, the first to second batteries B1 and B2 of 12V for charging the 24V power generated by the alternator 10 are connected in series and the first to second batteries B1 and B2 voltage. The voltages of the first to second batteries B1 and B2 are always the same according to the detection unit 30 and the first to second battery B1 and B2 voltages detected by the detection unit 30. It is composed of a battery equalizer 20 for maintaining.

As described above, the battery equalizer 20 compensates the discharge of the second battery B2 due to the use of the 12V load in the 24V system using the 12V first to second batteries B1 and B2 to compensate for the first to second batteries. The voltages of B1 and B2 are kept constant at all times.

By the way. In order to perform such a function by the battery equalizer 20, a DC / DC converter (not shown) is used inside the DC / DC converter, in which the 12V output voltage of the battery is equal to 24V of the input voltage generated by the alternator 10. The voltage is controlled to be half so that the voltages of the first to second batteries B1 and B2 are the same.

At this time, in order to control the voltages of the first to second batteries B1 and B2 equally, the voltage of the first battery B1 is detected by the sensing unit 30 and the first sensing resistor R _S1 . The voltage is sensed by the partial pressure of the second sensing resistor R _S2 , and the voltage of the second battery B2 is sensed by the partial pressure of the third sensing resistor R _S3 and the fourth sensing resistor R _S4 . In addition, the voltage of the first to second batteries B1 and B2 is sensed for various analog signal processing.

In addition, a dummy resistor R _D of several KΩ is used for control stability at no load of the DC / DC converter.

However, the use of the sensing resistors R _S1 to R _S4 of the sensing unit 30 used for the stable supply of the battery voltage in this way generates a dark current of the battery when the vehicle is stopped.

In particular, the dummy resistor R _D of several KΩ has a problem of accelerating the imbalance of the first to second batteries B1 and B2 due to discharge of the lower battery when the vehicle is stopped for a long time.

The dummy resistor R _D can increase the resistance value to satisfy the dark current regulation of the vehicle. However, due to the control circuit characteristics of the battery equalizer 20, the dummy resistor R _D can not increase the sense resistor unconditionally, and the dummy inserted for control stability at no load. There is a problem in that resistance exists as an inevitable dark current source.

The present invention has been made to solve the above problems, an object of the present invention is to convert the 24V power supply to 12V so as to use a 12V power source independently in a large vehicle of the battery of the vehicle battery in the equalizer for stable supply The present invention provides a battery voltage sensing device for a commercial vehicle battery equalizer that can remove a dark current generated when a vehicle is stopped by a dummy resistor used to sense a voltage.

According to an aspect of the present invention, there is provided a battery voltage sensing device of a battery equalizer for a large vehicle, which senses a voltage at a partial pressure of a sensing resistor for each of the first to second batteries connected in series through a sensing unit. It characterized in that it further comprises a switching unit intermittent by the ignition signal according to the starting state between the two batteries and the sensing unit.

In the present invention, when the ignition signal is turned on, the switching unit connects the first to the second battery and the sensing unit, and when the ignition signal is turned off, it is characterized in that the first to the second battery and the detection unit is cut off.

According to the present invention, when the vehicle is started, that is, when the ignition signal is turned on, the first to second battery voltages are normally detected by the sensing resistor in the sensing unit, but the ignition is turned off. When turned off, the first to second batteries and the sensing unit are blocked to prevent the battery power from being discharged to prevent the dark current.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings, and the same parts as in the prior art use the same reference numerals and names. In addition, the present embodiment is not intended to limit the scope of the present invention, but is presented by way of example only and those skilled in the art will be capable of many modifications within the technical spirit of the present invention.

2 is a circuit diagram illustrating a battery voltage sensing device of a battery equalizer for a large vehicle according to an exemplary embodiment of the present invention.

As shown here, 12V first to second batteries B1 and B2 for charging a 24V power generated by the alternator 10 are connected in series and each of the first to second batteries B1 and B2 is connected. The voltage of the first to second batteries B1 and B2 is measured according to the detector 30 for sensing the voltage and the voltage of each of the first to second batteries B1 and B2 sensed by the detector 30. It is composed of a battery equalizer 20 for keeping the same at all times.

In addition, the switching unit 40 intermittently interposed by the ignition signal IG is configured between the first to second batteries B1 and B2 and the sensing unit 30.

At this time, the switching unit 40 is turned on and off according to the output value of the NPN transistor TR and the NPN transistor TR operated by the ignition signal IG, and thus the first to second batteries B1 and B2 and the sensing unit ( 30) PMOSFETs Q1 and Q2 that switch between.

Accordingly, in the normal operation state, as the ignition signal IG is turned on, the NPN transistor TR is turned on and the PMOSFETs Q1 and Q2 are turned on, so that the first to second batteries B1 and B2 and the sensing unit 30 are turned on. The first and second sensing resistors R _S1 and the second sensing resistor R _S2 are divided into voltages, and the voltage of the second battery B2 is detected. The partial pressure of the resistor R _S3 and the fourth sensing resistor R _S4 is sensed.

However, when the ignition is turned off, as the ignition signal IG is turned off, the NPN transistor TR of the switching unit 40 is turned off and the PMOSFETs Q1 and Q2 are turned off. , B2 and the sensing unit 30 are disconnected from each other so that the power source of the first to second batteries B1 and B2 supplies the dummy resistor R _D and the first to fourth sensing resistors R _S1 to R _S4 . As it is not discharged through, it is possible to prevent the generation of dark current.

As described above, the present invention provides a vehicle by a dummy resistor used to detect a voltage of a battery of a vehicle in a battery equalizer for stably supplying a 24V power source to 12V so that a 12V power source can be used independently in a large vehicle. There is an effect that can remove the dark current generated when the stop.

Claims (2)

In the battery voltage sensing device of a large-sized vehicle battery equalizer for sensing the voltage by the partial pressure of the sensing resistor for each of the first to second batteries connected in series through the sensing unit, A switching unit intermittently interposed by an ignition signal according to a starting state between the first and second batteries and the sensing unit Batteries voltage sensing device for a large vehicle battery equalizer, characterized in that made further comprising. The method of claim 1, wherein the switching unit connects the first to second batteries and the sensing unit to each other when the ignition signal is turned on, and connects the first to second batteries and the sensing unit to each other when the ignition signal is turned off. Blocking Battier voltage sensing device of a large vehicle battery equalizer characterized in that.

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