GB2032155A - Lamp Failure Device - Google Patents

Abstract

Reed relays are used to monitor the correct functioning of bulbs by detecting the current supplying the bulbs. In the event of bulb failure, the release of the relay may cause a lamp or L.E.D. indicating correct operation to be extinguished; by drawing power from the circuit under test to feed the lamp or L.E.D. indicating correct operation, circuit power may be monitored as well. With bulbs which are operated a large number of times, a differential circuit may be used to minimise the risk of feed failure. <IMAGE>

Description

SPECIFICATION Lamp Failure Device for Use on Vehicles or Any other Type of Lighting Including Instrumentation The purpose of this device is to give an indication to the driver of any type of vehicle that any of its light bulbs have failed whether on the vehicle itself or any associated trailer or caravan.

In addition it could be used for any other purpose where such an indication is desirable, e.g.

instrumentation, security, etc.

This function can be carried out by the use of integrated circuit technology, thermal relay, but this has severe disadvantages especially when a product for a number of varying applications is considered.

The device below makes use if a dry reed relay which can detect the presence of a current flowing to bulb/lamp in question, the disappearance of the magnetic flux allowing the armature and contact of the relay to restore to its normal position which by the choice of contact configuration will allow an alarm (audio or visuai, e.g. bulb, LED) to be activated in either a positive or negative mode.

The correct operation of dual filament or a pair of lamps can be detected either by the use of two separate coils and dry reed relay inserts, or, alternatively, by the use of differentially wound coils, i.e. two coils with additive, opposing or flux from one coil only acting upon a single dry reed insert.

The current to power the indication device can be drawn from the bulb/lamp circuit itself If a negative indication rnode is used, i.e. the LED or other device goes out if the tested bulb/lamp fails.

The advantages this device are:- a) rugged construction with very extended life-typically 108 operations b) cheap and easy to manufacture c) non critical circuit parameters d) easily adapted to any wattage of bulb, AC or DC e) positive or negative indication of failure f) suitable for positive of negative earth vehicles g) suitable for any supply voltage h) any number of units can be interconnected so that only a single indication of failure device is necessary i) can be either used as an add on accessory or, alternatively, built in from new j) very low insertion loss k) can be used if required with one indication of failure device per lamp so that the failed lamp position can be defined I) can be easily encapsulated to provide additional mechanical and environmental protection m) small size

Claims 1. A means whereby the correct functioning of vehicle lights is monitored using reed relays.

a) As claimed in 1 but to also monitor the correct functioning of instrumentation bulbs.

b) As claimed in 1 but to also monitor any other type of lighting e.g. Security where the continuous monitoring of operation is required.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (1)

1. **WARNING** start of CLMS field may overlap end of DESC **.

   SPECIFICATION Lamp Failure Device for Use on Vehicles or Any other Type of Lighting Including Instrumentation The purpose of this device is to give an indication to the driver of any type of vehicle that any of its light bulbs have failed whether on the vehicle itself or any associated trailer or caravan.

   In addition it could be used for any other purpose where such an indication is desirable, e.g.

   instrumentation, security, etc.

   This function can be carried out by the use of integrated circuit technology, thermal relay, but this has severe disadvantages especially when a product for a number of varying applications is considered.

   The device below makes use if a dry reed relay which can detect the presence of a current flowing to bulb/lamp in question, the disappearance of the magnetic flux allowing the armature and contact of the relay to restore to its normal position which by the choice of contact configuration will allow an alarm (audio or visuai, e.g. bulb, LED) to be activated in either a positive or negative mode.

   The correct operation of dual filament or a pair of lamps can be detected either by the use of two separate coils and dry reed relay inserts, or, alternatively, by the use of differentially wound coils, i.e. two coils with additive, opposing or flux from one coil only acting upon a single dry reed insert.

   The current to power the indication device can be drawn from the bulb/lamp circuit itself If a negative indication rnode is used, i.e. the LED or other device goes out if the tested bulb/lamp fails.

   The advantages this device are:- a) rugged construction with very extended life-typically 108 operations b) cheap and easy to manufacture

   c) non critical circuit parameters d) easily adapted to any wattage of bulb, AC or DC e) positive or negative indication of failure f) suitable for positive of negative earth vehicles g) suitable for any supply voltage h) any number of units can be interconnected so that only a single indication of failure device is necessary

   i) can be either used as an add on accessory or, alternatively, built in from new j) very low insertion loss k) can be used if required with one indication of failure device per lamp so that the failed lamp position can be defined I) can be easily encapsulated to provide additional mechanical and environmental protection m) small size

   Claims 1. A means whereby the correct functioning of vehicle lights is monitored using reed relays.

   a) As claimed in 1 but to also monitor the correct functioning of instrumentation bulbs.

   b) As claimed in 1 but to also monitor any other type of lighting e.g. Security where the continuous monitoring of operation is required.