JPS5845147Y2 - Dansen Kenshiyutsu Sochi - Google Patents

Description

[Detailed description of the invention] This invention detects when the used filament Y of the bi-beam filament button and low beam filament of a vehicle headlight is broken and automatically switches to the unused filament. The present invention relates to a disconnection compensation circuit, and particularly aims to provide a compensation circuit that does not affect the lighting of each filament t and has excellent vibration resistance.

The present invention is a distant relative of this, by connecting a coil in series with each filament of the headlamp, connecting one end of each capacitor to the midpoint of the connection, and connecting the other end with a resistor and a backflow prevention diode. Connect to each filament above,
In addition, the gate button and cathode of a thyristor forming a compensation power supply path to each filament are connected to both ends of the resistor, and the inductance L of the coil, the capacitance C of the capacitor, and the DC resistance of the series circuit including each element are connected to both ends of the resistor. It is characterized in that each constant is set so that the sum R is R<24T-.

The details will be explained below based on the attached drawings.

Referring to FIG. 1, numeral 1 is a switch having fixed contacts 2 and 3 that can be connected to and separated from an on-vehicle power supply (not shown), and 4 is a headlamp equipped with a bi-beam filament 5 and a low-beam filament 6.

Coils γ and 8 are arranged so as not to interact with each other and are connected in series to the bi-beam filament 5 and the low-beam filament 6.

9 and 10 are capacitors whose one end is connected to the connection midpoint between each of the filaments 5 and 6 and the coils 1 and 8, and the other end is commonly connected to the resistor 11, and the bi-beam is connected from the other end of the resistor 11. Current limiting resistor 1 on filament 5
2 and a backflow prevention diode 13, and a backflow prevention diode 14 is connected to the twisted low beam filament 6.

Furthermore, the gate buttons and cathodes of thyristors 15 and 16 are connected to both ends of the resistor 110, and the anodes thereof are connected to the contacts 2 and 3 of the switch 1 to form a compensation power supply path to the filaments 5 and 6.

1. When contact 2 of switch 1 is connected to the power supply as shown in Figure 1, the beam filament 5 passes through the
In a normal case, the headlight 4 is turned on.

At this time, the terminal voltage of the high beam filament 5 is prevented from rising rapidly by the counter electromotive force of the coil T, and rises relatively slowly at 1, which is stable at a steady current.

Therefore, capacitor 9, resistor 11. The gate voltage of the thyristor 15 (voltage drop due to the resistor 11) due to the charging effect on the capacitor 9 through the diode 14 and the low beam filament 6 also appears as a voltage one-time characteristic shown in FIG. 2A.

In other words, the conditions for triggering the thyristor 15, 16'r depend on the voltage drop across the resistor 11 connected between the gate and the cathode, but when the filaments 5 and 6 are energized under normal conditions, almost no voltage drop occurs due to the resistor 11. , the trigger level shown in FIG. 2 is not reached at 1, so the thyristor 15 is not triggered.

Similarly, when the contact 3 of the switch 1 is connected to the power supply and the filament 6 is energized to turn on the headlight 4, the voltage drop across the resistor 11 due to the constant charging current of the capacitor 10 triggers the thyristor 16. First, the headlight 4 performs normal lighting by switching the switch 1.

However, contact 2 of switch 1 is connected to the power supply,
If the high beam filament 5 of the headlight 4 is lit and breaks midway through, the lighting current that was flowing through the filament 5 in the headlight 4 will be cut off by opening the filament 5, but due to the back electromotive force of the coil T. In order to have the effect of continuously flowing current, a capacitor 9, a resistor 11,
Diode 14 button and normal low beam filament 6
The capacitor 9 is rapidly charged through the path,
As a result, the voltage drop across the resistor 11 also reaches the trigger level of the thyristor 15 as shown in FIG.
5 is made conductive and electricity is supplied to the low beam filament 6 via the diode 14, so that the headlamp 4 can be switched on and turned on.

In this case, the inductance of coil 1 and capacitor 9
The capacitance C button and the total DC resistance R of the series circuit including these are determined by setting each constant so as to satisfy the relationship R2[. A high and large trigger pulse can be obtained, and the thyristor 15 can be made conductive with certainty.

If the high beam filament 5 of the headlight 4 is already disconnected when it is energized, that is, if the high beam filament 5 cannot be turned on at the initial stage of lighting, the high beam filament 5 will suddenly turn on as shown in Figure 2 C. Similarly to the above, a trigger pulse is generated by the initial activation of the oscillating current to conduct the thyristor 15 (1), and in the same way, the low beam filament (6) of the headlamp 4 can be turned on instead.

In other words, if the high beam filament 5 is already broken at the beginning of energization or is broken during energization (on the side where the headlight 4 is used), the low beam filament 6 is used instead of the high beam filament R5. It is possible to energize it and turn it on as an alternative.

In addition, if the low beam filament 6 is disconnected at the time of energization or is disconnected at the start of energization, the trigger pulse (passed through the capacitor 10) causes the thyristor 16 to conduct, and the current limiting resistor 12. Electricity is supplied to the beam filament 5 of the headlamp 40 through the diode 13, and its illuminance can be reduced and adjusted by the resistor 12 to switch the headlamp 40 on.

In this way, the present invention connects a coil in series with each of the no-beam filament and the low-beam filament R of the headlight, and connects the coil from the middle point of the connection to the capacity filament via the capacitor button and resistor. , a thyristor triggered by the voltage drop across the resistor is connected to each filament 'F to form a compensating power supply path capable of conducting current;
Moreover, by setting each constant so that the series circuit of the coil, capacitor button, and resistor satisfies the conditions for generating oscillating current when the external filament is disconnected, it can be used reliably and stably without complicating the circuit configuration of the device. It is possible to detect a break in the side filament and switch to the normal filament on the unused side and energize it, thereby providing a compensation circuit that contributes to safe night driving.

[Brief explanation of drawings]

FIG. 1 is an electrical wiring diagram showing an embodiment of the disconnection compensation circuit according to the present invention, and FIG. 2 is a voltage one-time characteristic diagram showing the gate voltage of the thyristor when the filament shown in FIG. 1 is normal and when the filament is disconnected.

Claims (1)

[Scope of utility model registration request] Connect a coil in series with each of the high beam filament Y and low beam filament of the headlamp, connect one end of each capacitor to the midpoint of the connection, and connect the other end of each capacitor in common to one end of the resistor. Connect a series circuit of a current limiting resistor and a diode from the other end of the resistor to the bi-beam filament, connect a diode to the low-beam filament, and selectively energize the anodes of both ends of the resistor to the two filaments Y. The gate and cathode of the thyristor connected to the fixed contact of the switch are connected, and the inductance L of the coil, the capacitance C of the capacitor, and the sum total R of the DC resistance of the series circuit including each element are R(2↓ ] A disconnection compensation circuit for a headlamp, characterized in that each constant is set so that.