JPS5850894B2 - Automotive light control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a light control device for an automobile that automatically turns on and off headlamps and the like according to the surrounding brightness and darkness.

Generally, in this type of automobile light control device, in order to ensure safety when driving the car,
It is necessary to ensure normal operation of the device.

The present invention has been made with this point in mind.The main circuit of the light control is provided in two parallel systems and has a back amplifier function, and a monitoring circuit is built in to monitor both systems. An object of the present invention is to provide an automobile light control device that detects and displays this.

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows the basic circuit configuration of an automobile light control device according to the present invention, in which a battery B is used as the main power source, and a relay RY is connected via an ignition switch SW1, a light switch SW2, and a transistor switch Q. and each of these switches S
A circuit in which a cancel switch SW3 is connected in parallel with WI, SW2, and a transistor Q is also provided in parallel with the circuit of the relay RY using the batch IJB as the main power source, and the a contact of the relay RY is inserted. A circuit consisting of a lamp L is connected to the base side of the transistor Q, and the transistor Q changes depending on the surrounding brightness state.
A control circuit A is provided to perform on/off control.

The control circuit A also includes an illuminance sensor (photodiode) 1 provided to detect external light, a switch group 2 for adjusting the sensitivity of the sensor 1, and a switch group 2 for amplifying the output voltage of the illuminance sensor 1. Arithmetic amplifier 3 and its amplification output■.

The first comparator 4 compares the first comparator 4 with the reference voltage 8; the integrating circuit 5 integrates the comparison output; the integrated output vQ is compared with the reference voltage 8; and a second comparator 6 that turns on and off.

In the figure, F indicates a main fuse provided in the main circuit of batch IJB, and F2 indicates a fuse for protecting lamp L from overcurrent.

The operation of the automobile light control device according to the present invention configured as described above will be explained below.

First, when the ignition switch SW1 and the light switch SW2 are closed, when the illuminance sensor 1 detects the illuminance from the outside, the detected output is amplified by the amplifier 3, and the amplified output (2) is obtained.

is first compared with the reference voltage 8 by the first comparator 4.

Next, the comparison output is integrated by the integrating circuit 5, and then compared again with the reference voltage 8 by the second comparator 6.

At this time, in the first comparator 4, ■.

When ≦■8, the comparison output becomes 1", and when ■o>■8, the comparison output becomes "L".

Furthermore, by integrating the comparison output (integration time ta) and comparing it with the reference voltage vR, the output of the second comparator 6 has an operating hysteresis characteristic between lHII and L11. Become.

That is, by the combination of the first comparator 4, the integrating circuit 5, and the second comparator 6, the disturbance light or the relay RY
In order to prevent malfunctions due to chattering or the like, the switching command of the transistor Q is provided with an operation hysteresis characteristic and noise absorption is performed.

Therefore, the output of the second comparator 6 enables instantaneous and reliable switching of the 1-transistor Q.

Next, when the output of the second comparator 6 is H'' (control circuit A
), transistor Q turns on and the electromagnetic coil of relay RY is energized, which closes the a contact of relay RY and turns on lamp L.
lights up.

Also, when the output of the second comparator 6 is 1+L 11 (
When control circuit A determines that the surroundings are bright),
Transistor Q is turned off and the electromagnetic coil of relay RY is deenergized, thereby opening the a contact of relay RY and turning off lamp L.

Further, even when controlling the lighting and extinguishing of the lamp L by the illuminance sensor 1 described above, the lamp L can be turned on by forcibly energizing the relay RY by turning on the cancel switch SW3.

Note that if this cancel switch SW3 is turned on even when the ignition switch SW1 is open and the engine is stopped, the lamp L can be turned on.
For example, an automatic return type switch that utilizes the balance between electromagnetic force and spring force is used as the switch SW3, so that the cancel switch SW3 can be closed only when the ignition switch SW1 is in the on state, and the ignition switch SW1 can be closed. When the cancel switch SW3 is turned off, the cancel switch SW3 automatically returns to release the cancel state, thereby preventing forgetting to turn off the lamp L.

The present invention provides such basic light control circuits in two systems in parallel as shown in FIG.
A circuit 8 for monitoring both these systems is integrated.

That is, in FIG. 2, the components 3, 4, 5, 6 and the transistor Q1 and relay RY in the basic circuit of FIG. The sections starting from .5 and 6 are shown in blocks as the write control main circuit T1, and the other system has the same configuration as the write control back amplifier circuit 12.

The monitoring circuit 8 also includes transistors Q1 . A matching circuit 9 that detects whether the respective outputs of Q2 are the same, a transistor Q3 that controls the photodiode 10 to turn on or off according to the NOR output thereof, and another circuit that is provided in parallel with the photodiode 10. A circuit consisting of a photodiode 11.

In addition, check relays 121 and 122 are connected in series to the collector sides of transistors Q1 and Q2, respectively, and a common contact circuit of each of these relays 121 and 122 is connected to the cathode side of photodiode 11 of monitoring circuit 8 and battery B. connected between.

Furthermore, a check relay circuit 13 is provided in parallel with the first and second systems, and is energized by being supplied with current from the batch IJB when the light switch SW2 is closed.

Note that the same symbols in the drawings as in FIG. 1 indicate the same constituent elements.

In the automobile light control device according to the present invention configured as described above, by providing a backup circuit 72 system in parallel with the main circuit 71 system, the entire device has a fail-safe function.
In order to ensure that each system of 1 and the backup circuit 72 is always operating normally, the monitoring circuit 8 performs constant diagnosis, and when a failure occurs in a failed system, it is detected and an indication to that effect is displayed. I am trying to get them to do this.

That is, the ignition switch SW1 is now on,
Light switch SW2 is off (check relay circuit 1
(The input sides of the main circuit 11 and the bank amplifier circuit 72 are short-circuited because the coil No. 3 is de-energized), the circuit of the check relay 121, the transistor Q1, the relay RY1, the check relay 122, the transistor Q2, A check current flows through each circuit of IJ relay RY2 (main circuit 11 and bank amplifier circuit 7).
Transistors Ql and Q2 even when each output of 2 is °L”
(Each circuit constant is determined so that a minute base current is supplied to each check relay 12L).
The a-contacts 122 are respectively closed, and as a result, a positive bias voltage is applied to the cathode side of the photodiode 11, so that it does not emit light.

At this time, the main circuit 71 or the backup circuit 12,
Transistor Q1.

Q2: If a failure occurs in even one part of the check relays 121 and 122, the check current will not flow.
The a contact of the check relay 121 or 122 is opened and the photodiode 11 emits light to indicate this fact.

Note that the check current is determined by the check relays 121 and 122.
The check current is a minute current determined mostly by the impedance of each coil (in ohms), and the check current is configured so that the relays RY1 and RY2 will not be energized.

Next, when both the ignition switch SW1 and the light switch SW2 are in the on state, the light switch SW
A current also flows through the coil of the check relay circuit 13 through the circuit 2, which energizes the two contacts and trips them from the b terminal to the a terminal, respectively, and the illuminance sensor 1 is connected to the main circuit 11 and the backup circuit 72, respectively. A detection signal will be sent.

As a result, each output of the write control main circuit 71 and its bank up circuit 12 (transistor Q1
and Q2 output) are constantly monitored by the matching circuit 9 of the monitoring circuit 8, and if the main circuit T1 and the backup circuit 72 are operating normally and both are producing +1 L" or H" output, the NOR output becomes H. ”, turning on transistor Q3, and as a result, photodiode 1
0 circuit is short-circuited and no light is emitted.

At this time, the circuit system of the main circuit 71 and the transistor Q1 or the backup circuit 72 and the transistor Q1
When a failure occurs in the circuit system No. 2 and the respective outputs do not match, the NOR output of the matching circuit 9 becomes "L" and the transistor Q3 turns off, causing the photodiode 10 to emit light and cause an abnormality. Perform display.

In this case as well, the circuits of check relays 121 and 122 operate to monitor each system doubly, as described above.

In addition, in the present invention, even if one control system fails when lighting the lamp L, the other control system provides backup, thereby preventing the lamp L from not lighting even when the surroundings become dark. In particular, in case of failure when lamp L is turned off,
Even if the lamp L remains lit in bright surroundings, it does not pose a problem to the driving of the vehicle.
No backup amplifier measures are taken.

As described above, in the automotive light control device according to the present invention, a back amplifier circuit is provided in parallel with the main circuit of the light control, and a monitoring circuit that constantly monitors the operating status of both systems is integrated. In addition to fully fulfilling the fail-safe function of the light control, in the event of a breakdown in the system, a notification to that effect (not only a light display but also an audible alarm may be issued) can be made. This has the excellent advantage of completely ensuring safety when the vehicle is running.

[Brief explanation of drawings]

FIG. 1 is an electrical wiring diagram showing the basic circuit configuration of a light control according to the present invention, and FIG. 2 is an electrical wiring diagram showing an embodiment of the invention. 1... Illuminance sensor, 2... Sensitivity adjustment switch group, 71... Light control main circuit, T2... Back amplifier circuit, 8...
...Monitoring circuit, 9... Matching circuit, 10,1
1...Photodiode, 121.122...
...Check relay, 13...Check relay circuit, SWl...Ignition switch, SWl...Light switch, SW3...
...Cancel switch.

Claims (1)

[Claims] 1 An electronic switch is turned on and off in response to a detection signal of the surrounding brightness and darkness from an illuminance sensor, and the lamp power supply circuit is automatically opened and closed via a relay connected to the main circuit of the electronic switch. In an automobile light control device, a backup circuit with the same configuration is installed in parallel with the main circuit of the light control, and the output status of the main circuit and backup circuit is constantly monitored, and when the two outputs do not match, the An automobile light control device characterized by incorporating a monitoring circuit that detects and issues an alarm.