JPH0215708Y2 - - Google Patents

Description

[Detailed description of the invention] <Technical field of the invention> This invention provides disconnection compensation for turning on other lamps when one lamp is disconnected in automobile taillights having stop lights, tail lamps, and turn signal lamps. Regarding equipment.

<Prior art and its problems> Conventional such disconnection compensation devices include circuit configurations such as those shown in Japanese Utility Model Publication No. 57-23226. The reality is that there is only a single alternative function, such as replacing the stop lamp or vice versa, and no consideration is given to mutual replacement or breakage of the turn signal lamp.

<Purpose of the invention> Therefore, the object of the invention is to provide an improved wire breakage compensation device having a mutual compensation function including the wire breakage of a turn signal lamp.

<Structure of the invention> The disconnection compensating device according to this invention is a disconnection compensating device for turning on another lamp as an alternative when one lamp is disconnected in a tail light for an automobile having a stop lamp, a tail lamp, and a turn signal lamp. When each lamp is normal, an OR circuit outputs the lighting signals from the tail lamp lighting switch, stop lamp lighting switch, and turn signal lamp lighting switch as is, and when each lamp is disconnected, an AND circuit determines the lighting signal and the disconnection signal. circuit and an Ex-OR circuit, and generates a second rectangular wave oscillation circuit in response to a lighting signal output by closing a tail lamp lighting switch and a disconnection signal output from a tail lamp disconnection detection circuit described later. Then, a lighting control signal is output to the stop lamp's drive circuit described below, and by closing the turn signal lamp lighting switch, a blinking signal is outputted via the first rectangular wave oscillation circuit and is output from the disconnection notification circuit of the turn signal lamp, described later. A lighting control signal is output to the drive circuit of the stop lamp in response to the disconnection signal generated by the stop lamp, and the lighting signal outputted by closing the stop lamp lighting switch and the disconnection signal output from the disconnection detection circuit of the stop lamp described below. a logic circuit that outputs a lighting control signal to a driving circuit for the tar signal lamp (described later) when the tail lamp is not lit, and outputs a lighting control signal to the driving circuit for the tar signal lamp when the tail lamp is lit; , a drive circuit that turns on and off each of the lamps in response to a signal output from the logic circuit; The lamp burnout detection circuit is provided with an input to the logic circuit.

<Description of Embodiments> FIG. 1 schematically shows a circuit example of a disconnection compensating device according to this invention. The logic circuit, which is generally designated by the symbol A, receives a voltage of Vcc from a battery (not shown), which is a direct current power source for an automobile, and includes a tail lamp lighting switch SW1, a stop lamp lighting switch SW2, a turn signal lamp lighting switch SW3, and an AND circuit. IC1,5,6,
8, 9, 10, IC3, 4, 11 which is an OR circuit,
It consists of IC2, 7, etc., which are Ex-OR circuits.
Connected to the input side of the AND circuit IC5 for the turn signal lamp L3 is a first rectangular wave oscillation circuit 4a for giving desired blinking to the turn signal lamp L3, and is connected to the input side of another AND circuit IC9. Connected to the side is a second rectangular wave oscillation circuit 4b for providing desired dimming to the stop lamp L2 when the tail lamp L1 is disconnected.
On the output side of the logic circuit A, there is a drive circuit 1 that lights up each lamp L1 to L3 according to this output signal.
a, 2a, 3a are connected, and each lamp L1 to L3
are connected to lamp disconnection detection circuits 1b, 2b, and 3b for detecting these disconnections.

To explain the operation of this circuit, first, each lamp L
1 to L3 are normal, when switch SW1 is turned on, the output of IC3 becomes high level, drive circuit 1a is driven, and tail lamp L1 lights up.
Next, when the switch SW2 is turned on, the output of the IC4 becomes high level, and the stop lamp L2 is lit through the drive circuit 2a. And switch SW
3 turns on, IC5 turns on the first rectangular wave oscillation circuit 4.
Since it receives the signal from a and outputs a square wave,
The drive circuit 3a is driven via the IC 11, and the turn signal lamp L3 repeatedly blinks in accordance with the rectangular wave.

Next, when the tail lamp L1 is disconnected, the tail lamp L1 will not turn on even if the switch SW1 is turned on and the output 1d of the IC3 becomes high level.
The disconnection detection circuit 1b detects the disconnection of the tail lamp L1, and its output 1c becomes high level. Since this output 1c and the output 1d of IC3 are both at a high level, the output of IC8 is at a high level, and the output of IC9 becomes a rectangular wave because the second rectangular wave oscillation circuit 4b outputs a rectangular wave. The stop lamp L2 is dimmed and turned on in the same way as the tail lamp L1 via IC4. When the stop lamp lighting switch SW2 is turned on while the stop lamp L2 is replacing the tail lamp L1 in this way, the output of IC4 becomes high level.
The stop lamp L2, which had been dimmed, is now fully lit.

Next, when the turn signal lamp L3 is disconnected, even if the switch SW3 is turned on and the output of the IC5 becomes a rectangular wave as described above, the turn signal lamp L3 does not blink, but the disconnection detection circuit 3b detects the disconnection. is detected and its output 3c becomes high level. Since this output 3c is high level and the output of IC5 is a rectangular wave, the output of IC6 is a rectangular wave, which drives the drive circuit 2a via IC7 and IC4, and the stop lamp L2 blinks instead of the turn signal lamp L3. repeat. When the stop lamp lighting switch SW2 is turned on while the stop lamp L2 is replacing the turn signal lamp L3 in this way, the output of IC4 becomes high level, so the blinking stop lamp L
2 is normal full lighting.

And when the stop lamp L2 is disconnected,
Even if the switch SW2 is turned on and the output of IC4 becomes high level, the stop lamp L2 does not light up, but the disconnection detection circuit 2b detects the disconnection and its output 2c becomes high level, so IC1
The output becomes high level. At this time, if tail lamp L1 is not lit, IC2 is Ex-
Since it is an OR circuit, its output is high level, and the IC
3, the drive circuit 1a is driven, and the tail lamp L1 lights up instead of the stop lamp L2.
Also, if the tail lamp L1 is on at this time, the output of IC2 will be low level, but the IC
10 becomes high level, drives the drive circuit 3a via IC11, and turns on the turn signal lamp L3.
is fully lit instead of the stop lamp L2.

FIG. 2 shows drive circuits 1a to 3 in FIG.
Examples of the drive circuit 1a and the disconnection detection circuits 1b to 3b are shown and have the same configuration, so only the drive circuit 1a and the disconnection detection circuit 1b will be described. A base resistor R1, which receives a lighting signal output by closing the lamp lighting switch SW1, is connected to the base of the transistor TR1, and the collector of the transistor TR1 is connected to the base of the transistor TR2. The emitter of the transistor TR2 is connected to a battery, which is a DC power source for an automobile, and its collector is connected to the tail lamp L1 via a backflow prevention diode D. A connection point a between the diode D and the lamp L1 is connected to one input terminal of the comparator COM, and is also connected to another DC power source, such as a DC-DC converter, via a resistor R2. This other power supply outputs an output voltage Vcc2 larger than the output voltage Vcc1 of the battery, and this voltage Vcc1
driven by. The other input terminal of the comparator COM is connected to a connection point between distribution resistors R3 and R4 (R4>>R3) connected in series to another DC power source, and a reference voltage Vs is applied thereto.

Now, the tail lamp lighting signal is connected to the base resistor R1.
is input and transistors TR1 and TR2 are turned on, if the tail lamp L1 is normal,
A current _I1 flows into the tail lamp L1 from another power supply via the resistor R2 and point a, but the resistor R2 is
Since the resistance is set to be extremely high compared to the internal resistance r of the tail lamp L1, the current I1 is minute compared to the lamp current I2 flowing from the battery to the ground through the emitter and collector of the transistor TR2, the diode D, and the tail lamp L1. The voltage Va entering the input terminal of the comparator COM is Va
=r(I1+I2)rI2Vcc1.

Next, when the tail lamp L1 is disconnected while the lighting signal is input to the base resistor R1 and the transistors TR1 and TR2 are turned on, the connection point a becomes floating and Vcc1<Vcc2.
It becomes VaVcc2. In this case, Vcc2−Vcc
1 voltage will be applied to the diode D, but since the diode D is set within the reverse breakdown voltage range, no problem will occur. On the other hand, if this diode D is not inserted, Va=Vcc2-Vcc1, which makes it impossible to detect the disconnection of the tail lamp L1.

On the other hand, there is no lighting signal input, and the transistor
When TR1 and TR2 are off and tail lamp L1 is normal, R ₂ ≫r is set, so
Va=0. Further, when the tail lamp L1 is disconnected, the input impedance of the comparator COM is high, so the voltage becomes VaVcc2. In this way, the potential at the connection point a changes to the transistor TR1.
And regardless of whether TR2 is on or off, the voltage will be close to Vcc2 only when the tail lamp L1 is disconnected, and it will show a different value from the normal case.
It becomes possible to detect disconnection.

<Effect of the invention> As described above, the disconnection compensation device according to this invention has an OR circuit that outputs the lighting signals from the tail lamp lighting switch, stop lamp lighting switch, and turn signal lamp lighting switch as they are when each lamp is normal. and an AND circuit that determines the lighting signal and the disconnection signal when each lamp is disconnected.
The Ex-OR circuit is equipped with an Ex-OR circuit, and lights up via a second square wave oscillation circuit in response to a lighting signal output by closing the tail lamp lighting switch and a disconnection signal output from the tail lamp disconnection detection circuit described later. A control signal is output to the stop lamp's drive circuit described later, and by closing the turn signal lamp lighting switch, a blinking signal is outputted through the first rectangular wave oscillation circuit and a blinking signal is output from the turn signal lamp's disconnection detection circuit described later. In response to the disconnection signal, a lighting control signal is output to the drive circuit of the stop lamp, and in response to the lighting signal output by closing the stop lamp lighting switch and the disconnection signal output from the disconnection detection circuit of the stop lamp, which will be described later. a logic circuit that outputs a lighting control signal to a drive circuit for the turn signal lamp when the tail lamp is not lit, and outputs a lighting control signal to the drive circuit for the turn signal lamp when the tail lamp is lit; a drive circuit that turns on and off each of the lamps in accordance with a signal output from the logic circuit; and a drive circuit that is connected to each of the lamps and detects the disconnection when the lamp is turned on and off, and sends the signal to the logic circuit. The lamp burnout detection circuit is provided with a lamp burnout detection circuit that inputs the input signal to the lamp burnout detection circuit.

Therefore, when the tail lamp is disconnected, the lighting control signal output from the logic circuit drives the stop lamp drive circuit to dim the stop lamp, and when the turn signal lamp is disconnected, the lighting control signal output from the logic circuit is The lighting control signal from the logic circuit drives the stop lamp drive circuit to light the stop lamp, and if the stop lamp is disconnected and the tail lamp is not lit, the tail lamp drive circuit is driven by the lighting control signal output from the logic circuit. If the stop lamp is disconnected and the tail lamp is on, the turn signal lamp drive circuit can be driven by the lighting control signal output from the logic circuit to turn on the turn signal lamp.

In this way, when the tail lamp or turn signal is disconnected, it is replaced by the stop lamp, when the stop lamp is disconnected, it is replaced by the turn signal lamp when the tail lamp is on, and when the tail lamp is off, it is replaced by the tail lamp. is possible,
It is possible to realize a disconnection compensation device having a mutual compensation function including disconnection of a turn signal lamp.

[Brief explanation of drawings]

FIG. 1 is a circuit block diagram showing an example of a wire breakage compensating device according to this invention, and FIG. 2 is a circuit diagram showing an example of the drive circuit and wire breakage detection circuit shown in FIG. 1. A...Logic circuit, SW1 to SW3...Lamp lighting switch, Vcc1...Automotive DC power supply voltage,
Vcc2... Separate power supply voltage.

Claims (1)

[Scope of utility model registration request] This is a disconnection compensation device for turning on another lamp when one lamp is disconnected in an automobile taillight having a stop lamp, a tail lamp, and a turn signal lamp, and a switch for turning on the tail lamp when each lamp is normal, and a switch for turning on the stop lamp. The lighting signal from the turn signal lamp lighting switch and turn signal lamp lighting switch is output as is.
Equipped with an AND circuit and an Ex-OR circuit that determines the lighting signal and the disconnection signal when the OR circuit and each lamp are disconnected, and the lighting signal output by closing the tail lamp lighting switch and the disconnection of the tail lamp as described below. In response to the disconnection signal output from the detection circuit, a lighting control signal is output to the stop lamp's drive circuit (described later) via the second rectangular wave oscillation circuit, and the turn signal lamp lighting switch is closed. Outputting a lighting control signal to a stop lamp drive circuit in response to a blinking signal outputted through an oscillation circuit and a disconnection signal output from a turn signal lamp disconnection detection circuit described later, and closing a stop lamp lighting switch. In response to the lighting signal output from the stop lamp and the disconnection signal output from the disconnection detection circuit described below of the stop lamp, if the tail lamp is not lit, a lighting control signal is output to the tail lamp drive circuit described later, and the tail lamp is turned on. a logic circuit that outputs a lighting control signal to a drive circuit described below for the turn signal lamp when the turn signal lamp is turned on; a drive circuit that turns on and off each of the lamps in accordance with a signal output from the logic circuit; A lamp disconnection compensation device comprising: a lamp disconnection detection circuit that detects the disconnection both when the lamp is turned on and when the lamp is turned off, and inputs a signal thereof to the logic circuit.