MONTAGE DE DIODES LUMINESCENTES CLIGNOTANTES

FLASHING LED LAMP ASSEMBLY

Abrégé anglais

A circuit comprising a flashing LED lamp assembly which is able to operate
from
various forms and types of sinusoidal or quasi sinusoidal a.c. signals and
power
sources with electrical voltages of upto 11,000 Volts and frequencies upto
100,000
Hertz applied at its input.

Revendications

CLAIMS
1. A flashing LED lamp assembly and control circuit including a reactive
element,
(Capacitor C1), in which the said reactive element is connected in series with
a
first a. c power supply terminal having a voltage upto 11,000 volts and a
frequency
upto 100,000 Hertz; one side of a fourth resistor,(R4), is connected in series
with
the said reactive element with the other side of the said fourth resistor
connected to
a first circuit node; the anode side of a second power diode, (D2), is
connected
to the said first circuit node with the cathode side of the said second diode
connected to a second a.c. power supply terminal; a second resistor, (R2),
connected between the said first a.c. power supply terminal and the second
a.c.
power supply terminal; a metal oxide varistor connected between the said first
a.c.
power supply terminal and the second a.c. power supply terminal; The cathode
side of a first power diode, (D1), connected to the said first circuit node
and the
anode side of the said first power diode connected to a second circuit node;
the
anode side of a first zener diode, (Z1), connected to the said second circuit
node;
the cathode side of the said first zener diode connected to a third circuit
node, (R
); the anode of the flashing LED, (with a built-in integrated circuit),
connected
to the said third circuit node; the cathode side of the said flashing LED
connected
to a fourth circuit node, (S); the anode side of a bank of one or more
ordinary
LED's connected in series and in cathode to anode configuration and in series
with
the cathode side of the said flashing LED and with the said fourth circuit
node; the
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cathode side of the said bank of LED's connected to the said second circuit
node;
a first resistor, (R1), connected between the said third circuit node and the
said
second circuit node; a third resistor, (R3), connected between the said third
circuit node and the second a.c. supply terminal; the positive connection of a
second polarised capacitor, (C2), connected to the second a.c. supply
terminal;
the negative connection of the said second capacitor connected to the said
second
circuit node.
2. A flashing LED lamp assembly and circuit as claimed in claim 1 wherein the
said
first zener diode, (Z1), depicted may range in value from 2 Volts to 250 Volts
and
rated upto 25 Watts.
3. A flashing lamp assembly and circuit as claimed in claim 1 wherein the said
first
resistor, (R1), depicted may range in value from 0.01 Ohm to 10 Million Ohms.
4. A flashing LED lamp assembly and circuit as claimed in claim 1 wherein the
said
reactive element, (capacitor C1), depicted may range in value from 0.0000001
micro farad to 1 farad.
5. A flashing LED lamp assembly and circuit as claimed in clams 1 and 2 and 3
and 4
wherein the relative positions of the said fourth resistor, (R4), and the said
reactive element, (Capacitor C1), are reversed.
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6. A flashing LED lamp assembly and circuit as claimed in clams 1 and 2 and 3
and 4
and 5 including a of number of non flashing LED's connected in series with the
said
flashing LED may range in number from 1 to 5500.
7. A flashing LED lamp assembly and circuit as claimed in claim 1 wherein the
said
second capacitor, (C2), may range in value from 0.001 micro farad to 1 farad.
8. A flashing LED lamp assembly and circuit as claimed in claim 1 wherein the
said
third resistor, (R3), may take any value between 1 Ohm and 10 Million Ohms.
9. A flashing LED lamp assembly and circuit as claimed in claim 1 wherein the
said
second resistor, (R2), may take any value between 1 Ohm and 10 Million Ohms.
10. A flashing LED lamp assembly and circuit as claimed in claim 1 and 2 and 3
and 4
and 5 and 6 and 7 and 8 and 9 wherein a fifth resistor which may take any
value
between 1 micro Ohm and 150 million Ohms and is or may be connected between
the said third circuit node and the said fourth circuit node.
11. A flashing LED lamp assembly and circuit as claimed in claim 10 wherein a
first
thermistor and in particular a self-heating current limiting thermistor is
placed in
series with the said fifth resistor and where the combination, (resistor and
thermistor), is or may be connected between the said third circuit node and
the
said fourth circuit node.
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12. A flashing LED lamp assembly and circuit as claimed in claim 11 wherein
the said
first thermistor is placed in series with the said fifth resistor and with a
second
similar thermistor and where the series combination, (thermistor and resistor
and
thermistor), is or may be connected between the said third circuit node and
the
said fourth circuit node.
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Description

CA 02095730 2001-05-15
A FLASHING LED LAMP ASSEMBLY
This invention relates to an electric circuit for driving in a practical
manner and causing
to flash on and off a bank of semiconductor devices, commonly known as Light
Emitting Diodes, (hereinafter referred to as LED's), by means of an
alternating
current and voltage, (hereinafter referred to as a.c. or a.c. power sources,
or the
mains), and operating with elecl:rical voltages of upto 11,000 Volts and
frequencies of
up to 100,000 Hertz. The circuit and LED's together form a practical LED
Flashing Lamp Assembly and includes a reactive element which is in series with
the a.c.
source.
When LED devices are driven from high voltage sources current limiting means
must
be provided to avoid destruction of the LED's. For a.c. voltage sources
current
limiting may be achieved using capacitors rather than the conventional means
of using
resistors. Such a reactive feed arrangement avoids excess heat dissipation and
provides the LED's with the required drive current. When further voltage
sensitive
control of LED's is required, for example to flash a bank of LED's on and off
by
means of voltage sensitive elemc;nt such as an LED with a built in integrated
circuit,
additional voltage stabilisation is also required. When using reactive
circuits in
general but particularly when high voltage sources are involved discharging
circuits
and spike limners must be provided. It is hoped than an innovation to provide:-
1. Drive current, with current limiting.
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CA 02095730 2001-05-15
2. Voltage dropping without the associated heat dissipation and energy waste.
3. Voltage stabilisation to enable other, voltage sensitive , forms of
electronics to be
driven.
4. Discharging circuits and spike limiters to avoid personnel from getting a
shock
after removal of supply and to avoid damage to electronic circuits from
external
voltage surges.
may be beneficial to Electrical / I3lectronic Engineering, especially as
applied to
providing a flashing Led lamp assembly.
Prior Art:
1. Portable safety device for attracting visual attention. (Figure 1).
PCT International publication N°. WO 90/ 14647.
This document discloses a flashing LED driving non-flashing LED's with a
conventional resistor for current: limiting means.
According to the present invention there is provided a flashing LED lamp
assembly and
control circuits including a reactive element, (Capacitor, C1), which element
is in
series with an a.c. source having a voltage upto 11,000 Volts and a frequency
upto
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CA 02095730 2001-05-15
100,000 Hertz, said assembly and circuit comprising 4 resistors, a metal oxide
varistor, 2 capacitors, a zener diode, a flashing type LED with a built-in
integrated
circuit, (which causes the LED t:o flash), 2 power diodes, and an unspecified
but
finite number of LED's, (without a built-in flasher circuit), connected in
series with
the flashing LED. The whole lamp assembly and circuit being configured and
arranged in accordance with Figure 1.
Figure 1 shows a schematic circuit. diagram of the preferred embodiment of the
invention. When an alternating power source is applied a capacitor, Cl, acts
to
limit the current that flows in the circuit. Resistor, R4, acts to protect the
circuit
against power spikes. if the power source is removed a resistor, R2, acts to
discharge the circuit. A metal oxide varistor acts to protect the circuit from
overvoltage surges. Diodes, D 1 and D2, rectifies the power source and a
polarised capacitor, C2, provides the d.c. base voltage at the capacitor's
declared
voltage and C2 charges to its rated capacity. A reference voltage is provided
by a
zener diode, Zl, and a resistor, R3, combination and a resistor, Rl, is
provided to stabilise the load, (a flashing LED with built-in integrated
circuit
connected in series with one or more non-flashing LED's). It may be desired to
provide additional control for the circuit in which case third and fourth
circuit nodes
are brought out to the circuit's terminals and when this is done additional
thermistor
protection can be inserted to protect the circuit.
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CA 02095730 2001-05-15
In the preferred embodiment the various circuit elements may have the
following
values:-
a) Zener diode Z1, 2 to 250 Volts, (upto 25 Watts).
b) Resistor Rl, 0.01 Ohm to 10 million Ohms.
c) Capacitor C1, 0.0000001 micro farad to 1 farad.
d) Capacitor C2, 0.001 micro farad to 1 farad.
e) Resistor R3, 1.0 Ohm to 10 million Ohms.
f) Resistor R2, 1.0 Ohm to 10 million Ohms.
Also,
1. The relative position of R4 and C 1 may be reserved without effecting the
operation
of the circuit.
2. The total number of non flashing LED's may range in number 1 to 5,500.
According to the present invention the salient points of the circuit described
are as
follows:-
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CA 02095730 2001-05-15
1. Identification of the fact that it is the flashing LED which causes the
other non-
flashing LED's, which are connected in series with the flashing LED, to flash,
with current limiting means provided elsewhere.
2. The incorporation of resistor l~l connected across the flashing and non-
flashing
LED assembly.
In the context of the following claims and the rest of this application the
term
"reactive" is to be interpreted in the Electrical Engineering or as defined in
the Physics
manner, that is to say as one would discuss "real" power and "reactive" power
in the
Electrical Engineering or Physics domain and to give the word "reactive" its
Electrical
Engineering or Physics meaning.
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