JPH11278176A - Electric power source blocking device for on-vehicle equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent wasting of battery voltage by introducing a detection signal from a noise detection circuit to detect ignition noise generated in accordance with engine starting and blocking voltage supply to the side of a load when this detection signal is not input. SOLUTION: Since generation of ignition noise is stopped when a driver turns off a key by stopping a vehicle after travelling the vehicle, voltage of an L-level is not input to a control part 5. This control part 5 starts time counting of a timer at the point of time when a detection signal of noise is not input and actuates a switching circuit 4a of an electric power source part 4 to turn off when two minutes pass. Consequently, battery voltage is not supplied to the side of the load, and wasting of the battery voltage is stopped in a short period of time after an engine is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-vehicle device which is used by inserting a plug into a cigarette lighter socket provided in a vehicle compartment, and more particularly to a small television or a television integrated VTR (TVCR) after the engine is stopped. The present invention relates to a power supply cut-off device for an in-vehicle device which can automatically cut off a power supply to prevent waste of battery voltage.

[0002]

2. Description of the Related Art In a driver's seat of a general vehicle, a cigarette lighter socket for smoking (hereinafter referred to as a cigarette lighter socket) connected to an on-vehicle battery is provided.
Socket) is provided, and a small TV or a TV-integrated VT is inserted into this socket.
Various in-vehicle devices such as R (TVCR) are used. Such an in-vehicle device does not consume the battery voltage if the power switch of the power supply unit is turned on after the engine is started, but the power switch is turned off after stopping the engine when leaving the vehicle. If you forget to do so, the output will drop quickly due to battery voltage consumption. When the battery voltage is reduced in this way, there is a problem that the engine cannot be started due to so-called dead battery. By the way, there has been proposed an automatic power-off device for a vehicle control circuit for automatically turning off the power (see Japanese Patent Application Laid-Open No. 3-78947). This is a relay switch connected between the power supply and the control circuit, a normally open operation switch connected to the signal input terminal of the control circuit and turned ON only when an external force is applied, and a switch for controlling the rotation of the engine. OF detection means for detecting rotation and the relay switch
F is provided with switching means. In this automatic power cut-off device, when a detection signal is output from the rotation detecting means with the rotation of the engine, the time after the engine is stopped is measured, and after a predetermined time, the switching means turns off the relay switch. Thus, the power supply to the vehicle control circuit can be automatically cut off within a preset time after the engine is stopped.

[0003]

However, the above-described automatic power supply cutoff device for a vehicle control circuit prevents the battery voltage from being wasted in the control circuit provided on the vehicle after the engine is stopped. Although it can be done, it is impossible to cope with the case where the user forgets to turn off the power switch of the in-vehicle device used by inserting the plug into the socket. For this reason, the problem that the engine cannot be started due to the waste of the battery voltage still remains.

[0004] The present invention has been made in view of the above-mentioned problems, and the battery voltage is not wasted even if the power of the vehicle-mounted device connected to the cigarette lighter socket is forgotten to be turned off. It is an object of the present invention to provide a power supply cut-off device for a vehicle-mounted device that can prevent a problem that cannot be performed.

[0005]

In order to achieve the above-mentioned object, according to the first aspect of the present invention, there is provided a vehicle-mounted vehicle for receiving a voltage by inserting a plug into a cigarette lighter socket provided in a vehicle cabin. A noise detection circuit that detects the ignition noise generated when the engine is started and a detection signal from the noise detection circuit are led to the power supply section of the equipment, and when this detection signal is no longer input, the voltage supply to the load side is performed. And control means for performing a control for shutting off. The noise detection circuit may include a capacitor having one end connected to the plug side, a diode having an anode connected to the other end of the capacitor, a cathode of the diode and a ground side. , And the detection signal is guided to the control means from a connection point between the cathode of the diode and the electric field capacitor. Also, in the invention according to claim 3, the in-vehicle device is provided with a screen including a screen for displaying an image.
An automatic cut-off mode in which the control unit automatically cuts off the voltage supply to the load side when the detection signal is not input due to the setting operation of the operation unit on a menu screen for selecting various modes. It is characterized by the following.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an electrical block diagram showing a power cutoff device for a vehicle-mounted device according to an embodiment of the present invention. The power supply cutoff device 10 for an in-vehicle device is applied to a small television used by inserting a plug 2 into a socket (cigar lighter socket) 1 provided in a vehicle compartment of a general vehicle. Is automatically shut off. The battery B of the vehicle is connected to a starter switch (not shown) and various electric circuit units (not shown) via a terminal portion T on the positive electrode side, and the positive electrode side of the socket 1 is connected. Also,
The negative terminal side of the battery B is connected to the ground, and the negative terminal side of the socket 1 is connected. The socket 1 has a conventionally well-known structure, in which a positive electrode and a negative electrode are provided on the inner side. If an ignition section containing a heater is pushed into the socket 1 and waits for a while, a cigarette can be ignited by the heat generated by the heater. it can. In addition to the small television having the plug 2 that fits into the socket 1, AV devices such as an AC / DC dual power supply TVCR (television integrated VTR) and a CD radio-cassette, when the plugs are inserted, the positive and negative electrodes come into contact with each other. The supply voltage from the battery B can be introduced to the power supply unit.

In the small television of this embodiment, in addition to the functions of a general television, the power supply cut-off device is operated on the menu screen by operating the remote controller 8 to automatically stop the voltage supply from the power supply unit 4 to the load side. The mode can be selected. The power supply unit 4 has the input side connected to the positive electrode of the plug 2, the output side connected directly to the control unit 5, and the display processing unit 6 and other loads via a built-in switching circuit 4 a. Circuit is connected. When the voltage from the battery B or the DC voltage from the ignition which is output when the engine is started is introduced, the power supply unit 4 sends the voltage to the load circuit to operate each unit, and the control unit 5 turns off the power supply unit. When the command signal is transmitted, the switching circuit 4a is turned off to cut off the supply of the battery voltage.

[0008] The power supply cutoff device 10 is configured by including the control unit 5 in the noise detection circuit 3 and is provided on the power supply unit 4 side of a small television. The noise detection circuit 3 includes a capacitor C
1, a diode D and an electrolytic capacitor C2. One end of the capacitor C1 is connected between the positive electrode of the socket 1 and the input side of the power supply unit 4. The capacitor C1 cuts a DC component of a voltage input through the socket 1 and the plug 2 at the time of starting the engine so as to reduce ignition noise. Take out only. The diode D has an anode connected to the capacitor C1.
At the other end, the cathode is connected to one end of the electric field capacitor C2 and the input terminal of the control unit 5, and half-wave rectifies the ignition noise from the capacitor C1. The electric field capacitor C2 has one end connected to the cathode of the capacitor C1 and the other end connected to the ground, smoothes the half-wave rectified noise waveform, and sends it to the control unit 5 as an L-level noise detection signal. It has become.

The control unit 5 is connected to the power supply unit 4, the noise detection circuit 3, the display processing unit 6, the receiving unit 9 and the like in one or two directions according to each function. The display processing unit 6 processes an image to be displayed on the screen 7 of the television, and receives a video signal from a video signal processing unit (not shown) by operating the remote controller 8 to display a program of a television program or display a menu. The user to select various modes. In this mode, D for automatically operating the power cutoff device 10 is set.
The C power automatic OFF function is also included, and when the user selects and operates the automatic shutoff mode of the DC power automatic OFF instruction on the menu screen, ON / OFF is displayed on the next screen, and either one can be selected. The remote control 8 is ON /
An OFF key, a channel key, an up / down key, a mode selection key, and the like are provided. When any key is operated, an operation signal is transmitted and transmitted to the control unit 5 via the receiving unit 9. The control unit 5 includes a CPU, a ROM, and an R
A microcomputer comprising an AM, which is provided with a timer and controls the operation of the entire television,
Various functions are executed based on an operation signal from the remote controller 8. Automatic DC power OF from remote control 8
When the operation signal of F is transmitted, after the detection signal from the noise detection circuit 3 is no longer input, the power supply unit 4 after a predetermined time (for example, 2 minutes) has elapsed by the timer.
Of the switching circuit 4a is turned off, and the supply of the battery voltage to the load side is interrupted.

Next, the operation of the power supply cutoff device will be described.
This will be described with reference to the timing chart of FIG. First, when the plug 2 of the television is inserted into the socket 1, a voltage of 12 V is supplied from the battery B to the power supply unit 4 so that the television can be watched. Here, the power switch is turned on by operating the remote controller 8, and a menu is displayed on the screen of the television as shown in FIG. Then, if you operate the fourth DC power automatic OFF from this menu,
On the next screen, as shown in FIG.
The function and ON / OFF are displayed. At this time, when the driver selects and operates ON, the control unit 5 shifts to the automatic cutoff mode. Thereafter, when the driver rotates the key, the voltage from the battery B is sent to the ignition coil, and the engine starts. At this time, ignition noise occurs and is superimposed on the voltage of the battery B. Therefore, at point a in FIG.
A voltage V1 having a noise waveform as shown in FIG. When this voltage V1 is led to the capacitor C1, the DC component is cut off, so that at point b in FIG.
As shown in (b), a noise waveform V2 around 0V is obtained. When this noise waveform V2 is input to the diode D, it is sent to the electrolytic capacitor C2 after being subjected to half-wave rectification. When the electrolytic capacitor C1 smoothes the noise waveform V2, FIG.
At point c, as shown in FIG.
3 appears and is sent to the control unit 5. This control unit 5
The level voltage V3 is determined as a noise detection signal, and the next state change is waited for.

When the driver stops the vehicle after running the vehicle, turns off the key, and stops the engine, the generation of ignition noise stops. Therefore, the L level voltage V3 is not input to the control unit 5. The control unit 5 starts counting the time of the timer when the noise detection signal is no longer input, and turns off the switching circuit 4a of the power supply unit 4 when two minutes have elapsed. Therefore, since the battery voltage is not supplied to the load side, the waste of the battery voltage stops in a short time after the engine is stopped. This prevents the battery voltage from dropping when the occupant leaves the vehicle after stopping the engine, even if he forgets to turn off the power switch of the TV. No problems occur when starting. However, if such an automatic shut-off mode is unnecessary, the D displayed on the television screen 7 as shown in FIG.
In the C power automatic OFF function, the OFF side may be selected and operated. In the above embodiment, an example in which the present invention is applied to a small television has been described.
It can be widely used in various AV devices such as a D-boom box, as well as in-vehicle devices such as refrigerators that are used by inserting a plug into a socket.

[0012]

As described above, according to the first aspect of the present invention, when the ignition noise is no longer detected on the power supply unit side of the vehicle-mounted device due to the stop of the engine, the voltage supply to the load side is performed. Since the battery is cut off, the battery for the vehicle will not be consumed by the vehicle-mounted device connected to the cigarette lighter socket. This has the effect of preventing the problem that the engine cannot be started. In addition, when the ignition noise is guided to the capacitor via the cigar lighter socket and the plug by starting the engine, the DC voltage from the vehicle battery is cut, and the noise superimposed on the voltage is reduced. Since only the waveform component is sent out to the diode, rectified and smoothed by the electric field capacitor, it is introduced into the control means as a noise detection signal, so that this control means cuts off the voltage supply to the load side, so the engine After stopping the power supply, the power transmission to the in-vehicle device is surely stopped to prevent the battery from running down. According to the third aspect of the present invention, the automatic shut-off mode can be selected on the menu screen while looking at the screen of the AV device by the driver's setting operation. This has the advantage that power transmission from the battery can be automatically stopped after the engine stops.

[Brief description of the drawings]

FIG. 1 is an electric block diagram showing a power cutoff device for a vehicle-mounted device according to an embodiment of the present invention.

FIG. 2 is a timing chart for explaining the operation of the power supply cutoff device of the vehicle-mounted device.

FIG. 3 is an explanatory diagram of a television screen on which a menu is displayed.

FIG. 4 is an explanatory diagram of a television screen on which the automatic power-off mode is displayed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cigarette lighter socket 2 Plug 3 Noise detection circuit 4 Power supply unit 5 Control means

Claims (3)

[Claims] 1. A noise detection circuit for detecting an ignition noise generated by starting an engine in a power supply unit of an in-vehicle device receiving a voltage by inserting a plug into a cigarette lighter socket provided in a vehicle interior. A power supply cut-off device for an in-vehicle device, comprising: a control unit that guides a detection signal from a noise detection circuit and cuts off voltage supply to a load when the detection signal is not input. . 2. The noise detection circuit includes: a capacitor having one end connected to the plug side; a diode having an anode connected to the other end of the capacitor; and a diode connected between a cathode of the diode and a ground side. The power cutoff device for a vehicle-mounted device according to claim 1, wherein the detection signal is guided to the control means from a connection point between the cathode of the diode and the electric field capacitor. 3. The on-vehicle device is an AV device having a screen for displaying a video, and the menu screen for selecting various modes is displayed when the detection signal is not input by a setting operation of an operation means. 3. The power supply cut-off device for a vehicle-mounted device according to claim 1, wherein the control means has an automatic cut-off mode for automatically cutting off a voltage supply to a load.