Signal lamps and apparatus
View Patent ↗An LED signal lamp comprises at least two separate LED arrays which have separate power feeds and wherein the LEDs of the arrays are positioned with respect to each other such that when lit they provide a composite light signal output and such that when the LEDs of only one of the two arrays are lit they provide a light signal with a visible distinctive pattern. A distinctive pattern is revealed, either lit or dark. Typically this pattern may be formed as a letter such as “X” or “F” or may be formed as a striped effect, for example. An LED signal apparatus comprises input signal power supply terminals 7,8 for the apparatus; a series connection of switch means S 1 to S 4 and a ballast load 6 connected across the supply terminals 7,8 ; an LED signal lamp 1,2 connected to the terminals to be supplied with current therefrom; and switch operating means D 1 to D 4 , in the supply path to the LED lamp, for controlling the state of the switch means S 1 to S 4 in the series connection, whereby total failure or substantially total failure of the current to the LED signal lamp results in said switch operating means D 1 to D 4 causing said switch means to open to disconnect the ballast load 6 from power from the supply terminals 7,8.
1. An LED signal lamp comprising at least two separate LED arrays which are connected in parallel such that they have separate power feeds and circuitry connected with the LED arrays and wherein the LEDs of the arrays are positioned with respect to each other such that when lit they provide a composite light signal output and such that should the current through either array fail, the LEDs of the other array may still light, and when the LEDs of only one of the two arrays are lit the lamp provides a signal with a visible distinctive pattern to provide a first indication of a failure of an array, said circuitry providing a second indication of said failure.
2. An LED signal lamp according to claim 1 wherein the distinctive pattern is revealed, either lit or dark.
3. An LED signal lamp according to claim 2 wherein the pattern is formed as an alphabetic letter or as a striped effect.
4. An LED signal apparatus comprising:
input signal power supply terminals for the apparatus;
a series connection of switch means and a ballast load connected across the supply terminals;
an LED signal lamp connected to the terminals to be supplied with current therefrom; and
switch operating means, in the supply path to the LED lamp, for controlling the state of the switch means in the series connection, whereby, during operation total failure or substantially total failure of the current to the LED signal lamp results in said switch operating means causing said switch means to open to disconnect the ballast load from power from the supply terminals.
5. An LED signal apparatus comprising:
input signal power supply terminals for the apparatus;
a series connection of switch means and a ballast load connected across the supply terminals;
an LED signal lamp connected to the terminals to be supplied with current therefrom; and
switch operating means, in the supply path to the LED lamp, for controlling the state of the switch means in the series connection, whereby, during operation total failure or substantially total failure of the current to the LED signal lamp results in said switch operating means causing said switch means to open to disconnect the ballast load from power from the supply terminals, wherein the switch operating means comprises an optocoupled diode for controlling an electronic switch such that, if electric current flows through the diode, the electronic switch closes and vice versa.
6. An LED signal comprising:
input signal power supply terminals for the apparatus;
a series connection of switch means and a ballast load connected across the supply terminals;
an LED signal lamp connected to the terminals to be supplied with current therefrom; and
switch operating means, in the supply path to the LED lamp, for controlling the state of the switch means in the series connection, whereby, during operation total failure or substantially total failure of the current to the LED signal lamp results in said switch operating means causing said switch means to open to disconnect the ballast load from power from the supply terminals, wherein the LED signal lamp comprises at least two separate LED arrays arranged jointly to provide a signal light output for the lamp and wherein each of said arrays has an individual switch control means in its supply path and said ballast load is connected to said supply terminals through a plurality of switch means each controlled by a respective one of the switch control means and the arrangement is such that, during operation, provided current flows to one of said arrays, the corresponding switch control means controls its respective switch means to permit current to flow through the ballast load.
7. An LED signal apparatus according to claim 6 , wherein detection means are provided to detect if any switch means is not permitting flow of current to the ballast load and, if this is the case, to provide a non-urgent alarm signal to that effect.
8. An LED signal apparatus according to claim 7 , wherein the detection means comprises a relay with its relay coil connected between switch means controlled points, in the supply to the ballast load, that during operation are at substantially the same voltage during closure of all switch means but which are at different voltages in the event of opening of only one of the switch means, whereby relay operating current flows through the relay coil.
9. An LED signal apparatus according to claim 6 , wherein, for each array, a pair of switch control means in parallel is connected in the supply to the array, such that, during operation, supply of current to the array is not interrupted solely as the result of failure of a single switch control means.
10. An LED signal apparatus according to claim 9 , wherein there is a pair of switch means for each array, each of which switch means is associated with a respective one of the pair of switch control means.
11. An LED signal lamp comprising at least two separate LED arrays which have separate power feeds and a switchable routing arrangement such that current may flow along different routes through the routing arrangement in dependence of a switching state of the routing arrangement, and wherein the LEDs of the arrays are positioned with respect to each other such that when lit they provide a composite light signal output and such that should the current through either array fail, the LEDs of the other array may still light, and when the LEDs of only one of the two arrays are lit the lamp provides a signal with a visible distinctive pattern providing a first indication of the failure of an array and the switchable routing arrangement is switched to provide a second indication of the failure of said array.
12. An LED signal lamp according to claim 11 , wherein the switchable routing arrangement comprises a plurality of switches.
13. An LED signal lamp according to claim 12 , wherein the LEDs of only one of the two arrays are lit, the routing arrangement is switched to enable current to flow through a particular route, thus activating the alarm.
14. An LED signal lamp according to claim 13 , wherein the switches are controlled by respective switch operating means responsive to the flow of current though an LED array.