JPH0525035Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a burnout check circuit for a warning lamp installed in an automobile.

[Background of the idea]

An example of a conventional warning lamp circuit of this type is the circuit shown in FIG. 3. This includes multiple warning lamps 1a, 1b, 1c, 1
For each sensor 2a, 2b, 2c, 2
n are connected, and when those sensors (switches) work (turn on), the warning lamp corresponding to that sensor lights up. In addition, each warning lamp is connected to a common check switch 4, that is, an ignition switch, through respective diodes 3a, 3b, 3c, and 3n, and is turned off when the generator starts operating. If there is a warning lamp that does not light up when the check switch 4 is closed, it can be confirmed that the warning lamp that does not light up is burnt out.

However, in the case of such a conventional warning lamp bulb check circuit, for example,
During maintenance of the vehicle or due to trouble in the circuit, the check switch 4 may remain closed and all warning lamps 1a may be turned off.
~ If 1n is left lit for a long time,
If the heat generated by these warning lamps becomes large enough to deform or melt the resin case or lamp socket that houses the warning lamp, causing the lamp to fall off, or the warning lens to become deformed and discolored, A problem arose.

[Purpose of invention]

The present invention was devised by focusing on these conventional problems, and includes connecting a thermally responsive element in parallel with the warning lamp in a lamp case that houses the warning lamp, and By interposing a resistor that limits the current flowing to each of the above warning lamps according to the operation of the element, if the temperature inside the case of the warning lamp rises, the current flowing to that warning lamp is automatically reduced and the warning is turned off. The object of the present invention is to provide a warning lamp burnout check circuit that can suppress heat generated by the lamp.

[Example of idea]

The present invention will be explained below based on the embodiment shown in FIGS. 1 and 2. The same parts between the structure of this embodiment and the structure explained in the conventional example will be designated by the same reference numerals as in the conventional example. Therefore, the explanation of the same structural parts will be omitted.

That is, in this embodiment, in the warning lamp bulb burnout check circuit described in the conventional example, a thermally responsive element (for example, a thermistor element) 5 is connected in parallel with the warning lamps 1a to 1n, and this thermally responsive element 5 and A resistor 6 is connected between the check switch 4 and the check switch 4. To explain this structurally, in FIG. 2, 7 is a case formed by dividing a plurality of warning lamp storage chambers 7a, 7b, 7c, and 7n by a partition wall 8, and the storage chambers 7a, 7n are separated by a partition wall 8. , 7b, 7c, and 7n, respective warning lamps 1a to 1n are attached via sockets 9, and diodes 3a to 3n are arranged in each housing chamber. Further, the thermally responsive element 5 and the resistor 6 are housed in one of the warning lamp housing chambers 7b. 10 is a printed circuit board for power supply, and 11 is a translucent front cover.

As described above, in this embodiment, the case 7 that houses the warning lamp is provided with the thermally responsive element 5 that detects the temperature inside the case 7, and when the temperature inside the case exceeds the normal temperature,
The resistance value of the thermally responsive element 5 decreases depending on the amount of heat generated. Therefore, when the entire current is divided into the warning lamp section and the thermally responsive element section, the current flowing through the thermally responsive element increases and, conversely, the current flowing through the warning lamp decreases compared to the normal state. This reduces the heat generated by the warning lamp and eliminates the problem of deformation of the case socket and the like. Therefore, if the temperature inside the case rises due to the warning lamps being lit for a long time, the thermal response element 5 operates to limit the current to each warning lamp, and the heat generation of the lamps is automatically suppressed. As a result, the inside of the case housing the lamp is not raised abnormally, and problems such as deformation of the case, socket, etc. due to heat generation can be solved.

[Summary of the idea]

As described above, the present invention provides the warning lamp 1a
-1n, sensors 2a-2n connected in series to the warning lamps, and a check switch 4 connected in parallel to the sensors, in which the warning lamps 1a-1n are housed. A thermally responsive resistive element 5 whose resistance value decreases as the temperature rises is arranged in the lamp case 7, and the thermally responsive resistive element 5 is connected in parallel to the warning lamps 1a to 1n, and a resistor 6 is connected to the check switch 4. This is a warning lamp bulb check circuit that is characterized by connecting the following warning lamps in series.

[Effect of idea]

Therefore, according to this warning lamp burnout check circuit, if the temperature inside the case rises due to the warning lamp being lit for a long time, the thermally responsive element 5 operates to limit the current to each warning lamp. Since the heat generation of the lamp is automatically suppressed, the inside of the case housing the lamp will not become abnormally high.
This has the effect of eliminating problems caused by deformation of sockets etc. due to heat generation.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the check circuit according to the present invention, FIG. 2 is an explanatory diagram of its structure, and FIG.
The figure is a circuit diagram of a conventional example. 1a~1n...warning lamp, 2a~2n
...Sensor, 3a-3n...Diode, 4...
Check switch, 5...Thermal response element, 6...Resistor, 7a-7n...Lamp housing chamber, 8...Dividing wall, 9...Socket, 10...Printed circuit board, 1
1...Front cover.

Claims (1)

[Scope of utility model registration request] In a warning lamp bulb out check circuit comprising warning lamps 1a to 1n, sensors 2a to 2n connected in series to the warning lamps, and a check switch 4 connected in parallel to the sensors, the warning lamps 1a to 1n A thermally responsive resistance element 5 whose resistance value decreases as the temperature rises is disposed in a lamp case 7 in which a lamp is housed, and the thermally responsive resistive element 5 is connected to the warning lamps 1a to 1a.
1n, and a resistor 6 is connected in series to the check switch 4.