FR2558121A1 - Fuse checker for motor vehicles - Google Patents

Abstract

The invention allows, by means of a light indicator, a driver to be warned of the blowing of a fuse as soon as it occurs. The fuse checker is formed, on the one hand, by detection modules which can be extended ad infinitum, comprising a switching diode 4 (i.e.: 1N4148, 1N914) and a protective resistor 3 (2 K.Ohms 1/2 watt) intended to detect the potential difference between the points 7 and 8 or 9 caused by the failure of one of the fuses and, on the other hand, by a warning module comprising a red light-emitting diode 5 and a protective resistor 6 (0.5 K.Ohm 1/2 watt) intended to warn the driver of the blowing of one of the fuses. This invention allows the avoidance of many incidents caused by the blowing of a fuse which is not detected in time.

Description

 The present invention makes it possible to know the state of the fuses of a.

vehicle at any time.

 At the present time, a driver only realizes that a fuse has failed when he uses the device protected by it.

 The controller according to the invention makes it possible, by means of indicator lights, to be notified of the breaking of a fuse as soon as it occurs.

 According to a first variant, an indicator located above each fuse lights up when the latter is defective. This system is only intended for a fuse compartment located in the passenger compartment and visible from the driver's seat.

 The second variant is made up of a system identical to that of the first, to which is added a warning light which, placed on the dashboard, lights up when one of the fuses is out of order. This model has the advantage of being able to be placed on a fuse compartment wherever it is located in the vehicle.

In the third variant, only a warning light placed on the dashboard warned of the breaking of one of the fuses. This system can be placed anywhere in the vehicle, it is cheaper than the other two systems,
A controller for two fuses is shown, in Figure I by the invention according to the first variant, in Figure 2 by that according to the second variant. The indices are intended to improve understanding of how it works; all components with the same number are identical.

In figure I, the fuse (I) is good; the anode and the cathode of the light-emitting diode (2) are at the same potential so it does not light up. The fuse (I ') is defective; the current flows from the battery (I2) into the light-emitting diode (2 ') ,. then in the resistor (4 ') to ground (I3) The diode (2') lights up. Each module (2,3,4) requires only a ground connection wire, their power being supplied by that of the fuse it controls. The light-emitting diode (2) is of the 3 mm or f 5 mm red type; the resistance (4) of 2 K. Ohms, I // 2 Watt; the switching diode (3) must at least support a direct current of 50 mA and a reverse voltage of 50 V (ex; ils4148,
IN9I4). This latter protects the light-emitting diode (2), which risks being directly connected to ground due to the destruction of the fuse and the very low resistance of vehicle signaling bulbs.

 A pilot light bulb (5 W) has a resistance of around 30 Ohms, which represents a current of 400 mA; a light emitting diode supporting only 20 mA, it would destroy without the protection of the switching diode (3) For a voltage of I2 V each module (2,3,4), of the invention according to the first variant, has a consumption, at rest (good fuse) of 72 mW, at work (faulty fuse) of 66 mW. these consumptions represent an energy 70 times less important than that consumed by a pilot light bulb (5 W). This system can control the fuses of all vehicles, whether their supply voltage is I2 V or 24 V.

In Figure 2, it is assumed that the fuse (9) is defective and the (9 ') good. The latter being good, the light-emitting diode (5 ') has its cathode and anode at the same potential, it does not light up. The fuse (9) being defective, the current flows, on the one hand from the battery (I2) in the light-emitting diode (5), the resistors (6,7) to ground (I3), on the other hand from the battery (I2) in the light-emitting diode (II), the resistance (IO), the diode (8), the resistance (7) to ground (I3) *
The light-emitting diodes (5six) light up. Because the fuse (9 ') is good, the cathode of the diode (8') is connected to the positf. Without the diodes (8.8 ') current would flow from the battery (I2) into the fuse (9' ), the resistors (7,7 ') to ground (I3); the light emitting diodes (5F51) would remain off, the circuits (I4, I4 ') being connected. your light-emitting diode (II) is plcée on the dashboard of the vehicle, it allows to warn the driver of the failure of one of the fuses.

The resistors (6,6 ', in) respectively protect the light-emitting diodes (5>5', II) as the diode (3) protects the light-emitting diode (2). Each module (5,6,7i, 8) requires the bond of two sons; the ground connection (I3) and the connection (I5) of the modules (5,6, 7,8) to the indicator light (II) on the dashboard. For a voltage of I2 V each module, of the invention according to FIG. 2, has a consumption, at rest (good fuse) of 96 mW, at work (faulty fuse) of 69 mW. These consumptions represent an energy 50 to 73 times less important than that of a pilot light bulb (5 W). The light-emitting diodes (5,11) are of type 3 mm or 5 mm red; the resistance (7) of
I, 5 K..Ohms, I / 4 of Watt; resistors (6, IO) of 0.5 K, Ohm I / 2 Watt; the diode (8) must at least support 50 mA of direct current and 50 V of reverse voltage (ex: lN4148, IN914).

 To install this system on vehicles supplied with 24 V, the value of all the resistors (6,7, IO) must be doubled. In order to improve the invention according to the second and third variants, it is possible to add a flashing cell to the light-emitting diode (II); a flashing light attracts the driver's attention more than a continuously lit lamp.

The fuse controller, object of the invention, can be presented in several ways:
- In elements of two and three modules allowing any driver to compose and place his controller himself. In this case the fixing system depends on the type of fuse used.

 - Mounted in series on vehicles, this controller will allow the manufacturer to obtain an additional argument during advertising and sales.

 - Mounted on vehicles with a large number of fuses, this controller will immediately detect the defective element and immediately warn the driver.

Claims (3)

 1. Fuse checker comprising a warning module characterized in that it is composed of a red light-emitting diode (5) and a protective resistance (6) of 0.5 K.Ohm 1/2 watt.  2. Fuse controller according to claim 1, characterized by  the fuse rupture detection diodes protecting the positive lines composed of a switching diode (4) [ex: lN4148, 1N914] and a protective resistor (3) [ex: 2 K.Ohms 1/2 watt ].  3. Fuse controller according to claim 2, characterized by the integrated circuits (not marked in the figure) tex: CD 40493 polarity reversers which, associated with the detection modules, allow the monitoring of the fuses protecting the ground lines.