JP2983880B2 - Automotive air conditioner panel switch lighting circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automotive air conditioner panel switch lighting circuit which illuminates a panel switch for operating an air conditioner and displays the operation / stop state of the air conditioner and the position of the switch at night.

[0002]

2. Description of the Related Art As a prior art relating to an automotive air conditioner panel switch lighting circuit, there is a technique disclosed in Japanese Patent Application Laid-Open No. Hei 6-171345. FIG. 5 is a circuit configuration diagram of the LED lighting circuit disclosed in the above publication. In the circuit shown in the figure, the cathode of the LED 51 is directly grounded,
A power supply _I.L., which is supplied in conjunction with night lighting of a vehicle, is connected to the anode side. When the night illumination of the car is turned on and the power supply _ILL is supplied, the panel switch 52 is shut off (OF).
The LED 51 also lights up in the state F). This allows the driver or the like to know the position of the panel switch at the time of operating the air conditioner at night, and has the effects of not impairing the safety of driving the vehicle and having excellent operability.
On the anode side of the LED 51, a night dimming circuit 53 is provided. This circuit weakens the light emission intensity of the LED 51 when the panel switch 52 is in the conductive (ON) state when the night illumination of the vehicle is turned on. Thus, the illumination of the panel switch 52 is prevented from being dazzling to the driver at night, and the lighting of the panel switch 52, that is, the operation of each function of the air conditioner is easily recognized in the daytime even when the surroundings are bright. can do.

FIG. 6 is a circuit configuration diagram of a group of automotive air conditioner panel switches using the circuit of FIG. A / C is air conditioner operation, ECON is economical operation of air conditioner, RE
C / FRS switches between air introduction / internal circulation at the air inlet of air conditioner, FACE, B / L, FOOT, F /
D and DEF are circuits for designating the outlet, respectively. The vicinity of Tr ₁ is a night light dimming circuit 53. A / C, E
In circuits other than CON, the cathode of the LED is grounded. However, in the A / C and ECON circuits, the cathode of the LED is connected to the A / C main amplifier 61 and is grounded in conjunction with turning on the blower switch 62.
Such an A / C main amplifier and blower switch 62
Is a configuration taken to operate the air conditioner only when the blower motor 63 is operating.

[0004]

In an automotive air conditioner panel switch lighting circuit using the prior art shown in FIG. 6, REC / FRS, FACE, B / L, FOO are used.
Panel switches other than A / C and ECON, such as T, F / D, and DEF, are lit and illuminated by LEDs in conjunction with nighttime illumination of the vehicle. However, the panel switches of A / C and ECON are not illuminated unless the blower switch is in the ON state, resulting in poor operability at night, which may impair the safety of driving a car.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a first object of the present invention is to provide A / C and ECO of an air conditioner panel switch for a vehicle in conjunction with night lighting of the vehicle.
An object of the present invention is to provide an automotive air conditioner panel switch lighting circuit for lighting all panel switch lights including N.

A second object of the present invention is to provide an automotive air conditioner panel switch lighting system in which the amount of panel switch lighting increases in the order of daytime OFF state, nighttime OFF state, nighttime ON state, daytime ON state of the panel switch as in the past. It is to provide a circuit.

[0007]

SUMMARY OF THE INVENTION According to the present invention, there is provided an automobile
Akon panel switch lighting circuit, panel switch lighting
Connected in series with the light emitting element for
Switch and the switch that works with the blower switch in parallel.
Connected to the car's night light switch
Switch, panel switch light emitting element and
First resistance element connected in series between the
And the night ground switch side of the first resistance element and the voltage supply
Zener diode connected between terminals and reverse biased
And the Zener diode voltage supply terminal side and ground
Panel switch lighting light emitting element and panel switch
And a second resistance element connected in series with the switch.
Switch and the switch linked to the blower switch
Panel switch lighting light emitting element when conducting
The amount of light is set to
It is configured to be more than the amount of light when conducting
Things.

[0008]

According to the present invention , even when the blower switch is shut off, the night earth switch is brought into a conductive state in conjunction with the night lighting switch of the automobile, one end of the panel switch illumination light emitting element is grounded, and the panel switch illumination light is emitted. The element lights up.

Further, when the blower switch and the panel switch are in the conductive state and the night earth switch is in the conductive state, the voltage generated at both ends of the first resistive element increases, the Zener diode breaks down, and the panel switch lighting light emitting element. Current flowing through the earth switch during the night is reduced than before, and the light-emitting element for panel switch lighting is in the daytime conduction state of the blower switch and the panel switch;
Light is emitted in the order of the night conduction state and the night interruption state.

[0010]

【Example】

[ Basic Configuration Example ] FIG. 1 shows a basic configuration on which the embodiment of the present invention will be described later .
Is a circuit configuration diagram of the air conditioner panel switch lighting circuit for an automobile is a configuration example. LED1 is used as a light emitting element for panel switch illumination. The figure shows only circuits related to the A / C switch of the air conditioner for the sake of simplicity. Between the power source I _G and ground LED1, panel switch 2, the transistor switch 3 are connected sequentially in series. The heater relay switch 4 linked to the blower switch is connected to the base of the transistor switch 3. Heater relay switch 4 when the blower switch is ON in an ON state in synchronization, the transistor switch 3 is applied a voltage from a power source V _B based O
N. The feature of this configuration is that the LED 1 is also connected to the ground by the night switch 5 which is a transistor switch provided in parallel with the panel switch 2 and the transistor switch 3. When the night light switch of the vehicle is turned on, a current is supplied to the power supply terminal _ILL , and the night earth switch 5 is turned on by applying a voltage to the base.

The following effects can be obtained by the configuration of the automotive air conditioner panel switch lighting circuit described above. First, when the panel switch 2 is turned on in the ON state of the blower switch, the LED 1 emits light and the push button of the panel switch is illuminated. This indicates that the air conditioner is operating. This is the basic operation of the automotive air conditioner panel switch lighting circuit, which can be obtained by the prior art. The characteristic operation of this configuration is that when the night lighting switch of the car is turned on, the night earth switch 5 is turned on, the LED 1 emits light regardless of the blower switch and the panel switch 2, and the push button of the panel switch is illuminated. It is. Thereby, the person operating the air conditioner can recognize the position of the push button of the panel switch at night.

Next, an embodiment of the present invention will be described with reference to the drawings.
I will explain.

Embodiment 1 FIG. 2 is a circuit configuration diagram of an automotive air conditioner panel switch lighting circuit according to a first embodiment of the present invention. The figure shows only circuits related to the A / C switch of the air conditioner for the sake of simplicity. Components having the same functions as those in FIG. 1 are denoted by the same reference numerals. LED1 and night earth switch 5
The first resistive element 6 is connected, a Zener diode 7 is connected between the night ground switch 5 side and the power source I _G of the resistance element 6 in these series between the. Voltage supply terminal side of Zener diode 7 and LED 1 of resistance element 6
The second resistance element 8 is connected in series with the LED 1 between the second resistance element 8 and the LED 1.

For the sake of simplicity, the path grounded by the blower switch and the panel switch 2 is referred to as a normal path, and the path grounded by the night light switch 5 is referred to as a night bypass. ON /
Expressed as OFF.

The first function of the resistance element 6 is to increase the resistance of the night bypass from the normal path so that the LED 1 in the state in which the night bypass is ON and the normal path is OFF.
, That is, the emission intensity of the LED 1 is made weaker than the state where the night bypass is OFF and the normal path is ON. The second function is to make the current flowing through the LED 1 when both the night bypass and the normal path are ON, that is, the light emission intensity of the LED 1 weaker than the state where the night bypass is OFF and the normal path is ON.

The second function of the resistance element 6 will be described qualitatively. The resistance value R ₂ of the resistance element 8 is 0 at night bypass.
In a state where the FF and the normal path are ON, the voltage generated between both ends of the resistor 8 and the LED 1 is set to a value smaller than the breakdown voltage of the Zener diode, that is, a value at which the voltage control by the Zener diode does not operate. Since a voltage drop occurs in the resistance element 6 when both the night bypass and the normal path are ON, the reverse bias voltage applied to both ends of the Zener diode is smaller than that in the state where the night bypass is OFF and the normal path is ON. To increase. Accordingly, by both the nocturnal bypass the normal path to set the resistance value R ₃ of the resistor element 6 to operate the voltage controlled by the Zener diode in the ON state, the second function is realized.

A specific description will be given using equations. Power I _G voltage V _CC of the value each R ₁ of the resistor element 9,8,6,
R ₂ , R ₃ and the voltage drop of the rectifying diode 10 are represented by V _D ,
The voltage drop of LED1 is represented by V _LED , and transistors 5 and 3
The voltage drop between the collector and the emitter at N
_TR1, V _TR2, the breakdown voltage of the zener diode and V _Z. At this time, the current flowing through the LED 1 is given by the following equation.

(I) When the night bypass is OFF and the normal path is ON (corresponding to the ON state of the panel switch during the day) According to the design condition that the Zener diode is not voltage-controlled, I ₁ = (V _CC -V _D -V _LED- V _TR2 ) / (R ₁ + R ₂ ) (1) (ii) When the night bypass is ON and the normal path is ON (corresponding to the ON state of the panel switch at night) The Zener diode is voltage controlled. Depending on conditions, I ₂ = (V _Z + V _TR1 −V _LED −V _TR2 ) / R ₂ (2) (iii) When the night bypass is ON and the normal path is OFF (corresponds to the panel switch night OFF state) ) Zener diode by design conditions that the voltage _{control, I 3 = (V Z -V} LED) / (R 2 + R 3) ...... (3) (iv) at night bypass OFF and normal path is OFF situ (Corresponding to the day of the OFF state of the panel _{switch) I 4 = 0 ...... (4} )

Here, R ₁ = 51Ω, R ₂ = 470Ω, R
₃ = 8.2 kΩ, V _D = 1 V, V _LED = 1 V, V _TR1 =
Assuming that 1 V, V _TR2 = 1 V and V _Z = 5 V, (1) to
From equation (3), I ₁ = 17 mA, I ₂ = 8.5 mA, I _2
3 = 0.46 mA, and I ₁ > I ₂ > I ₃ > I ₄ = 0... (5) holds, and LE illuminates the push button of the panel switch.
The light emission intensity of D is the strongest in the ON state during the day, and thereafter, the ON state at night, the OFF state at night, and the OFF state during the day.

Embodiment 2 FIG. 3 is a circuit configuration diagram of an automotive air conditioner panel switch lighting circuit according to a second embodiment of the present invention. The figure shows a circuit related to the A / C switch of the air conditioner for simplifying the description. Components having the same functions as those in FIGS. 1 and 2 are denoted by the same reference numerals.

The difference from the first embodiment is that the second resistance element 8
Is connected between the LED1 side of the first resistance element 6 and the panel switch. The function of the resistance element 6 is the same as that of the first embodiment.

In the cases (i) to (iv) shown in the first embodiment, the current flowing through the LED 1 of this embodiment is given by the following equation.

(I) Daytime ON state of panel switch Due to the design condition that the Zener diode is not voltage controlled, I ₁ = (V _CC −V _D −V _LED −V _TR2 ) / (R ₁ + R ₂ ) 6) (ii) the design condition that the nighttime ON state Zener diode of the panel switches voltage _{control, I 2 = (V Z +} V TR1 -V LED -V TR2) / R 2 + (V Z -V LED) / R ₃ ... (7) (iii) Night state of panel switch I ₃ = (V _Z −V _LED ) / R ₃ ... (8) According to the design condition that the Zener diode is voltage-controlled. Daytime OFF state of the switch I ₄ = 0 (9)

In the cases (i) and (iv), the current value is expressed by the same equation as in the first embodiment. Here, for the same circuit conditions such as the resistance value as in the first embodiment, from the expressions (6) to (8), I ₁ = 17
_{mA, I 2 = 9.0mA, I} 3 = 0.49mA _{next, I 1> I 2> I} 3> I 4 = 0 ...... (10) is satisfied, similarly Example 1, the emission intensity of the LED, Daytime ON state, nighttime ON state, nighttime OFF state, daytime OFF state are in this order.

Embodiment 3 FIG. 4 is an overall configuration diagram of a circuit of an automotive air conditioner panel switch group according to a third embodiment of the present invention, and shows a usage example of a circuit related to an A / C switch of the air conditioner of FIG. It is.

The structure will be described. Descriptions common to FIG. 6 of the prior art are omitted. The circuit of FIG. 2 is directly applied to the LED ₇ and LED ₈ of the A / C and ECON panel switches related to the operation of the air conditioner and the economical operation of the air conditioner,
Other LED light emitting circuits have a circuit configuration in which the panel switch 2 is directly grounded without the heater relay switch 4 linked to the transistor switch 3 and the blower switch in FIG. The resistance element / LED group 41 corresponds to the second resistance element 8 and the LED 1 in FIG. The switch group 42 is a panel switch. Each panel switch is a switch of an air conditioner operation circuit (A / C main amplifier, inside / outside air servo, mode servo) corresponding to each panel switch, and a switch of the normal path of the LED light emitting circuit (corresponding to panel switch 2 in FIG. 2). And are linked. The resistance element group 43 corresponds to the first resistance element 6 in FIG. The LED drive circuit 44 corresponds to a portion configured by the transistor 5, the Zener diode 7, the resistor 9, and the diode 10 in FIG.

The present invention is used for A / C, EC
This is a light emitting circuit of LED ₇ and LED ₈ corresponding to the ON switch. Here, the transistor switch 3 is provided in the A / C main amplifier 45. Blower switch 46 is off
Heater relay switch 4 is turned ON at the set turns ON within the heater main relay 47 to a position other than the transistor switch 3 is in an ON state is applied a voltage from a power source V _B based.

The characteristic effects of the present invention can be obtained by the night bypass. In this embodiment, the night bypass of the light-emitting circuits of the LEDs ₇ and ₈ and the night bypass of the other LED light-emitting circuits have a common configuration. For this reason, at night, when the night lighting switch of the car is turned on to supply power to the _ILL and the transistor switch 5 in the LED drive circuit 44 is turned on, not only the LEDs ₇ and ₈ but all the LEDs are turned on. It is grounded and a voltage controlled by the Zener diode 7 is applied to light up. The strength is weaker than when each switch of the switch group 42 is turned ON and an earth circuit in parallel with the earth circuit by the transistor switch 5 is formed. Thus, the operator of the air conditioner can recognize the positions of all panel switches even at night, and can distinguish the ON / OFF state of each panel switch.

[0029]

According to the onset Ming automotive air conditioner panel switch lighting circuit according to the present invention, in conjunction to night lighting switch during blower switch is shut off, the air conditioner panel switch Automotive A / C, all including ECON The panel switch illumination is turned on, and the air conditioner operator such as a driver can easily recognize the position of the panel switch at night, so that the operability is improved and the safety of driving the vehicle is ensured.

In addition , according to the vehicle air conditioner panel switch lighting circuit of the present invention , the panel switch lighting light emitting element has the following intensity in the daytime conduction state, nighttime conduction state, and nighttime interruption state of the blower switch and the panel switch. The air conditioner operator can recognize the position of each panel switch in the OFF state even at night, and can distinguish the ON / OFF state of each panel switch.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram of an automotive air conditioner panel switch lighting circuit which is a basic configuration example used for describing the present invention .

FIG. 2 is a circuit configuration diagram of an automotive air conditioner panel switch lighting circuit according to the first embodiment.

FIG. 3 is a circuit configuration diagram of an automotive air conditioner panel switch lighting circuit according to a second embodiment.

FIG. 4 is a circuit configuration diagram of a group of automotive air conditioner panel switches according to a third embodiment.

FIG. 5 is a circuit diagram of a conventional LED lighting circuit.

FIG. 6 is a circuit configuration diagram of a group of automotive air conditioner panel switches according to the related art.

[Explanation of symbols]

1,51 LED, 2,52 panel switch, 4 heater relay switch, 5 night earth switch, 7
Zener diode, 45, 61 A / C main amplifier, 46, 62 blower switch, 47 heater main relay, 53 night dimming circuit.

Claims (1)

(57) [Claims] An automotive air conditioner panel switch lighting circuit in which a panel switch lighting light emitting element, a panel switch, and a switch linked to a blower switch are sequentially connected in series between a voltage supply terminal and ground. When connected in series to a panel switch lighting light emitting element
In addition, a switch linked to the panel switch and blower switch
Is connected in parallel to the switch, and night ground switch interlocked with the night light switch of the motor vehicle, the panel switch illumination light emitting element and the nighttime ground switch
A first resistance element connected in series between the first resistance element and the night earth switch side of the first resistance element and a voltage supply terminal
Zener diode connected between and reverse biased
Between the Zener diode voltage supply terminal and ground.
Panel switch Light emitting element for lighting and direct with panel switch
And a second resistor element connected to the column, and linked to the panel switch and the blower switch switch
Light emitting element for panel switch illumination when
The light intensity of the child
So that the light intensity is higher than when the switch is in the conductive state.
A lighting circuit for an automotive air conditioner panel switch.