IT201600112984A1 - LIGHTING EQUIPMENT WITH BUILT-IN CIRCUIT FOR EMERGENCY LIGHTING - Google Patents

Description

LIGHTING DEVICE WITH BUILT-IN CIRCUIT

FOR EMERGENCY LIGHTING

The present invention generically refers to a lighting device, such as an electronic LED bulb, with built-in circuit for emergency lighting.

More specifically, the invention relates to an electronic circuit, complete with battery, which, suitably incorporated in addition to the circuits present in any ordinary lighting fixture, such as an electronic LED bulb, allows it to be transformed into a lighting fixture for emergency.

Lighting bulbs are devices that include a converter of electrical energy into light, an electrical / electronic circuit for powering this light source, an electrical / mechanical connection system and a transparent protective casing.

The bulbs have different formats based on the standardization that has occurred in the technical evolution to incorporate the different possible light sources; the most common shapes are the bulb ones, with E27 or E14 screw connector, created to encapsulate the incandescent tungsten filament, and the light tubes with a diameter of 26 mm or 15 mm, created for fluorescent sources with indirect discharge. of low pressure gas.

The advent of solid-state lighting sources (LEDs) has evolved the technology of bulb and tube shapes by replacing in both cases the content of these bulbs, but preserving their external appearance; This is how LED bulbs were born, characterized by very high energy efficiency, in which the built-in LEDs are driven by an electronic power supply that converts the 230V AC power supply into a form suitable for LEDs. White LED bulbs have spread to the market pervasively, replacing almost every type of traditional filament light source, from traditional tungsten filament bulb bulbs to more modern halogen bulbs.

Thanks to greater energy efficiency, LED bulbs are also replacing electronic bulbs, the so-called “compact fluorescent”. The availability of small batteries allows the integration of the emergency power function inside the new LED bulbs or the addition of the emergency function to the bulbs themselves through an accessory to be interposed between the bulb and the lamp holder.

The object of the present invention is to provide a lighting device equipped with a universal electronic circuit, complete with battery, which, added to the pre-existing circuits in each electronic bulb, allows it to be transformed into an emergency bulb.

Another purpose of the present invention is to provide a universal emergency circuit for lighting devices, which allows to detect, automatically and directly on the system where the lighting device is installed, an activation condition of the emergency lighting. regardless of the state of the ignition switch.

Another object of the present invention is to provide a universal emergency circuit for lighting appliances, which allows the use of traditional LED bulbs without modifying existing lamp holders and / or lighting systems. A further purpose of the invention is to create a universal emergency circuit for lighting equipment, which is able to monitor the emergency condition with very low energy expenditure.

These and other purposes are achieved by a lighting device with an incorporated circuit for emergency lighting, according to claim 1 attached; other detailed technical characteristics, according to the invention, are provided in the further dependent claims.

Advantageously, the present invention refers to a new electronic circuit, complete with battery, which, added to the pre-existing circuits in each electronic light bulb, allows it to be transformed into an emergency light bulb with the following functions:

- in the presence of a 230V (AC) power supply on the lamp holder, the bulb turns on with full light and at the same time the built-in emergency battery is recharged;

- if you turn off the isolator switch of one of the two conductors that power the lamp holder, the light bulb goes out, battery charging stops and the light bulb goes into a stand-by state;

- if there is no voltage on the entire circuit of the lamp holder upstream of the isolating switch, the bulb turns on in emergency with reduced light using the built-in battery.

This new electronic circuit, adaptable to all LED bulbs, is connected in series to the input of the original electronic ballast of the LED bulb, manages a rechargeable battery using the electric current that powers the electronic converter of the bulb, manages a dedicated set of LEDs used only for the emergency lighting function that are isolated from the LEDs dedicated to the ordinary lighting of the bulb and, finally, incorporates a control device for managing the emergency function, which analyzes the voltage at the ends of the bulb power supply terminals, identifying the emergency lighting condition and distinguishing it from an ignition switch off condition.

Further objects and advantages of the present invention will become clear from the following description, which refers to an exemplary and preferred, but not limiting, embodiment of the lighting apparatus with incorporated circuit for emergency lighting, according to the invention, and the accompanying drawings, in which:

- figure 1 shows an ignition system of a traditional light bulb LT with phase L interruption by means of the ignition switch I; - Figure 2 shows an ignition system of a traditional LT light bulb with phase L interruption, via the ignition switch I, and highlighting the parasitic capacities CPC towards the other conductors of the electrical system subjected to the phase potential;

- figure 3 shows an ignition system of a traditional light bulb LT with neutral interruption N and with ignition switch I;

- figure 4 shows an ignition system of a traditional light bulb LT with neutral interruption N, by means of switch I, and highlighting the parasitic capacitances CPN towards earth; Figure 5 shows a schematic block diagram of a known type of electronic LED light bulb; - Figure 6 shows a block diagram of an electronic LED light bulb with the new emergency circuit incorporated, according to the invention; - figure 7 shows the electric diagram of the electronic light bulb of figure 5 with incorporated the emergency circuit, according to the present invention;

Figure 8 shows a perspective view of an E14 olive-shaped LED bulb with the universal emergency circuit and the battery incorporated, according to the present invention;

- figure 9 shows an exploded and detailed view of the light bulb in figure 8, according to the invention;

- Figure 10 shows a perspective view from above of a 6-7W LED filament bulb with E27 ball socket that incorporates the emergency circuit, according to the invention;

Figure 11 shows a detailed view of the circuits of the light bulb and of the emergency circuit of Figure 10, according to the present invention;

- Figure 12 shows a diagram relating to the signal detection thresholds seen by the microcontroller at the input of the amplifier of the circuit of Figure 7, according to the invention; Figure 13 shows a schematic diagram of the main operating states of the microcontroller used in the circuit of Figure 7, according to the present invention.

With reference to the aforementioned figures, in particular the attached figure 6 shows the same electronic LED bulb of figure 5 (the latter of the traditional type), equipped with a LED light source 10, which diffuses the light through the transparent plastic bulb 14 and which is connected to a LED power supply 11 (connected in turn to the terminals 12 of the lamp holder 13), in which an emergency circuit 15, a battery 16 and an additional LED light source 17 necessary for the lighting function are incorporated of emergency.

In the attached figure 6 the simplicity of the solution is already evident in which the new emergency circuit 15 is connected in series to the input conductors of the original power supply 11 of the bulb, while the battery 16 is connected to the emergency circuit 15 with its two conductors and the additional LED light source 17 is connected in turn with two dedicated conductors.

With particular reference to figures 7, 8, 9, 10 and 11, the new emergency circuit 15 can be adapted to all electronic bulbs and has the following characteristics:

• uses the elements Di, D2, LV1, Ci, C3, C_LDE, Ri, R2, R3, Ql, LDE1, LDE2, ..., LDEN;

• it is connected in series to the input of the power supply 11 of the electronic light bulb (input D_LD or Driver Led);

• manages the battery 16 using the electric current that flows in the electronic light bulb; • manages a dedicated set of LEDs LDE1, LDE2, ..., LDEN (which constitute the emergency light source 17), used only for the emergency lighting function and isolated from the LEDs LD1, LD2, ..., LDN (which they constitute the ordinary light source 10) dedicated to ordinary lighting and originally installed in the bulb;

• incorporates a C_LDE element for managing the emergency function, which analyzes the state of the circuit located upstream of the bulb, distinguishing the various possible configurations of this circuit by measuring the electrical parameters read on the lamp holder 13.

The emergency light bulb according to the present invention, in addition to a traditional electronic light bulb, allows to detect on the system in which an emergency lighting activation condition is installed (lack of the AC power supply of the system) and to discriminate it from simple opening of the ignition switch of the light bulb itself, opening which is caused by the normal switching off of the light bulb voluntarily commanded by the user.

With reference to figures 1, 2, 3 and 4, it can be seen that, when the circuit breaker I is on, the AC voltage of the 230V electrical network is present at the ends of the two power supply terminals L, N of the bulb LT; in this condition, the bulb according to the invention is switched on normally and the built-in battery 16 is recharged.

When the circuit breaker I opens, the light bulb according to the invention goes out like a normal light bulb, but the emergency circuit 15 continues to monitor the electric line to detect the presence of the power supply upstream of the switch I.

In practice, all the cases described in figures 1 to 4 can occur:

• with particular reference to fig. 1, the switch I disconnects the phase conductor L in a system in which the two conductors are well insulated from the other electric lines (typical case of a table or floor lamp with the plug inserted so that the switch cuts the conductor L); in this case, with the switch I open, the residual AC voltage coupled through the parasitic capacitance of a few pF of the switch I itself remains at the ends of the bulb, while the residual AC voltage at no load is very small, but measurable (of the order of a few tenths of a Volt); • with particular reference to fiq. 2, the switch I disconnects the phase conductor L in a system in which the two conductors are adjacent to other electrical lines of the building (typical case of a ceiling or wall lamp wired directly in a civil electrical system, in which the conductor L is isolated by the switch I, but the sectioned part of the conductor runs in the raceways and in the electrical conduits near other conductors connected to L, at the potential of 230V, 50Hz or 115V, 60Hz); in this case, with the switch I open, the measurable voltage across the bulb is the sum of the AC voltage coupled through the parasitic capacitance of a few pF of the switch I itself and the voltage induced through the parasitic capacitance CPC for coupling with the electric cables adjacent to the interrupted section, the latter contribution of a higher entity, while the AC voltage across the bulb, when empty, is within the range of values from a few volts to a few tens of volts, depending on the parasitic couplings;

• with particular reference to fiqs. 3 and 4, the switch I disconnects the neutral conductor N; in this case, the conductor L, at the highest potential of 230V, 50Hz or 115V, 60Hz, is always connected to one of the two inputs of the bulb and the parasitic capacitances towards ground CPN allow to easily couple a voltage of several Volts, no-load , at the ends of the bulb, with the switch I open.

In all cases, the light bulb according to the invention, using the built-in emergency circuit 15, which is powered by the battery 16 consuming only a very small part of the accumulated energy, measures the AC voltage at its input and compares it with multiple pre-defined profiles. -stored to determine the state of the electric circuit to which the lamp holder 13 to which the bulb is connected is connected upstream.

For this purpose, two different thresholds Si, S2 are stored inside the microcontroller Mi of the emergency circuit 15, linked to the profiles of the AC voltage (signal M) read on the lamp holder 13 (as shown in the graph in fig. 12) and the circuit power supply integrated in the bulb distinguishes all the possible cases, by comparing with the two thresholds Si, S2 memorized, according to the following methods.

1) If the voltage on the lamp holder 13 corresponds to intensity and profile lower than the threshold Yes, this means that the AC voltage upstream of the switch I is missing regardless of the state of the switch I open or closed and, as a consequence of this condition, the light source 17 of the emergency LEDs turns on.

2) If the voltage on the lamp holder 13 corresponds to intensity and profile included between the thresholds S1 and S2, this means that the switch I is open, but there is an AC voltage upstream of the switch I itself and, in this condition, the light source 17 of the emergency LEDs remains off; the bulb is in a waiting state, ready to intervene by switching on the emergency and possibly, in this intermediate state, the bulb, if suitably configured in the factory, can switch on the light source 17 of the emergency LEDs with reduced light, so as to be used as a marker or marker in dark places.

3) If the voltage on the lamp holder 13 corresponds to an intensity and profile greater than the threshold S2, the switch I is closed and the AC voltage is present upstream, with the consequence that the light source 17 of the emergency LEDs remains off since the source bright 10 of the ordinary lighting LEDs is certainly on.

The light bulb according to the invention is therefore able to distinguish the states of

- switch I open and upstream AC power supply present e

- circuit breaker I open and AC power supply upstream absent,

allowing to automatically turn on the light source 17 of the emergency LEDs in any real emergency condition (absence of electricity upstream of switch I) regardless of the state of switch I.

In particular, when the management microcontroller M1 of the C_LDE element of the emergency circuit 15 identifies the emergency condition by analyzing the AC input voltage and comparing it with the thresholds S1 and S2, the aforementioned management microcontroller M1 also commands the automatic switching on of the emergency LEDs LDE1, LDE2,…, LDEN using the energy stored in the built-in battery 16 and possibly adjusts its intensity to optimize battery use 16.

This operating regime continues until the microcontroller M1 identifies again the presence of the AC power supply at 230V, 50Hz or 115V, 60Hz upstream of the switch I, by recognizing a voltage (seen by the microcontroller M1) at the frequency F of network (signal M of Fig. 12), which is greater than the threshold S1, in which case the emergency is inhibited again by switching off the emergency light source 17.

A second function of the light bulb according to the present invention, during an emergency phase, allows the control of the light source 17 of the emergency LEDs by means of the switch I even in the absence of the AC network upstream of the switch itself.

This operation of the light bulb according to the invention, in the emergency phase, is shown in detail in the state diagram of fig. 13.

As soon as a condition of absence of AC voltage is identified upstream of the switch I, the light bulb goes into a first state of emergency (state C in fig. 13) turning on the relative light source 17 of the emergency LEDs.

At the same time, following the activation of this state, the microcontroller M1 activates a new operating mode in which the input impedance measurement operates (this operating mode is not active in the presence of AC voltage upstream of the switch I) .

Once the input impedance measurement is activated, the operation of the light bulb is regulated by the impedance variations caused by any maneuvers of the switch I.

If switch I was open at the time of activation of the emergency, a first maneuver of switch I from open to closed causes a strong reduction in the impedance read by the light bulb at its input; in fact, the closure of the switch I determines the connection of the light bulb to the low impedance electrical loads present on the electrical network. This first transition from high impedance to low impedance is interpreted by the microcontroller M1 as a confirmation of the fact that the light source 17 of the emergency LEDs must remain on, since the user, by closing the switch I, has confirmed his need for have the light on, even if there is no AC voltage upstream.

The bulb then passes into the state D of the diagram of fig. 13.

If now the user operates switch I a second time by placing it in an "open" state, the intention is to turn off the light, even if there is no AC electricity upstream. Then, the light bulb, detecting the impedance transition from low impedance to high impedance, at this second transition, turns off the light source 17 of the emergency LEDs (it switches to state E of fig. 13), preserving the battery energy. 16 for possible subsequent use.

Subsequently, a third transition from high impedance to low impedance (corresponding to a new third action of the user who closes switch I) detected by the microcontroller M1 causes the light source 17 of the emergency LEDs to be switched on again (state D of fig. 13), and so on for subsequent maneuvers (the light bulb passes alternately from state D to state E in fig. 13).

At the same time, the microcontroller M1 continues to measure the AC input voltage and compare it with the thresholds S1 and S2 and, at any time, if the AC input voltage (signal M in fig. 12) exceeds the threshold in intensity and profile. S1, the microcontroller M1 immediately ceases the impedance measurement mode and switches off the light source 17 of the emergency LEDs (with an immediate return to state A of fig. 13); in fact, this means that the AC voltage upstream of the switch I has been restored and therefore the emergency condition must still be inhibited, with the consequence that the light bulb resumes its ordinary operation.

Returning to the moment of activation of the input impedance measurement (state C of fig. 13), if the circuit-breaker I was closed at the moment of the activation of the emergency, a first operation of the circuit-breaker I from closed to open causes the increase in the impedance read by the bulb at its input; in this case, the microcontroller M1 immediately identifies the user's will to turn off the light while preserving the battery 16 for later use and, therefore, the microcontroller M1 immediately turns off the light source 17 of the emergency LEDs (transition to state E of fig. . 13), continuing however to measure the impedance and the AC input voltage and continuing to compare it with the thresholds S1 and S2.

Subsequent impedance transitions determine the switching on or off of the light source 17 of the emergency LEDs as a function of the sign of the impedance transition (the light bulb switches alternately between state E and state D in fig.

13), while exceeding the S1 threshold always has the effect of interrupting the impedance measurement and turning off the light source 17 of the emergency LEDs. In this way, the bulb combines a real emergency function (the light source 17 of the emergency LEDs always switches on in the absence of AC electricity upstream of the switch I, regardless of the state of the switch I itself, even when the latter is open), the possibility of being controlled in the on or off position as desired by the user, by means of the same switch I, even in the emergency condition, allowing the user to possibly preserve the energy of the battery 16; all this, however, only after the emergency condition has been detected and the light source 17 of the emergency LEDs has turned on automatically.

A further advantage of the mode of operation described is that of synchronizing the ignition state of the LED light sources 10, 17 to the actual command state that the switch I would have in the presence of the AC network upstream.

In this way, if the user decides to turn off the light source 17 of the emergency LEDs in the emergency phase itself, by appropriately controlling the switch I, when the AC mains returns, the switch I is already in a circuit condition " open ”and, therefore, the light bulb remains correctly off without unnecessarily consuming electricity when the mains returns.

Similarly, if the user leaves the light bulb on in an emergency after acting on switch I, when the mains returns, the light bulb will be switched on again. The bulb is constructed in such a way that the circuits for monitoring the power supply condition and the AC voltage upstream of the switch I, as well as for monitoring the impedance, consume a very small part of the energy present in the battery 16, guaranteeing continuity of operation. in monitoring mode with switch I open, for several months continuously (for example consuming half of the available energy in 3 months).

In this way, the regularity of operation of a light bulb is guaranteed, which is turned on at least once every few days (since the light bulb is switched on is the only moment in which the internal battery is recharged 16).

The operating autonomy of the bulb in an emergency can be set from a minimum of 30 minutes to a few hours by appropriately adjusting the light intensity of the source 17 of the emergency LEDs, i.e. by varying the intensity of the driving current.

If necessary, the intensity adjustment can be managed so that initially the brightness is more intense to allow the user to perceive less the reduction in brightness from ordinary operation; subsequently, the brightness can be progressively reduced automatically in order to maximize the battery life 16.

The emergency circuits are constructed, according to the state of the art of emergency lighting, so as to turn off the emergency light source 17 when the voltage of the battery 16 falls below a minimum value in order not to damage the battery 16 itself ( minimum interruption function).

The operation of the lighting fixture with built-in circuit for emergency lighting, object of the invention, is essentially the following. The original power supply 11 of the bulb includes an electronic circuit D_LD (LED Driver) with AC voltage input at 230V, 50Hz or 115V, 60Hz or universal from 85V to 250V, 50 ÷ 60Hz and with a direct current output suitable for driving of the series of ordinary lighting LEDs LD1, LD2,…, LDN belonging to the light source 10.

This electronic circuit D_LD can be of any type, such as:

- passive with capacitive drop or resistive drop; - active with high frequency switching converter with isolation transformer (for example flyback) or without transformer (for example buck or inverted buck);

- active with switching converter and power factor correction.

In all cases, the input current of the power supply 11 is an alternating current at the mains frequency (50Hz or 60Hz), the intensity of which is proportional to the power absorbed by the bulb. For example, in the case of a 3.5W LED bulb with capacitive drop power supply, the power supply 11 absorbs about 45mArms.

The direct output current is regulated by the power supply 11 to the value necessary for the correct power supply of the ordinary lighting LEDs LD1, LD2, ...., LDN of the light source 10.

This parameter depends on the LED configuration used: if the LEDs used are, for the most part, of low power each, the current is low and the voltage is high, vice versa if a few higher power LEDs are used.

It is therefore evident that it is not convenient to adapt any emergency lighting circuit to the output, since, with the same bulb power, it would not easily match the various different possible electrical output configurations.

As for the input, however, the power supply current at 50Hz, with the same power, is similar for all light bulbs; in this case, in reality, the intensity of the current depends on the power factor of the power supply 11, but can vary at most by a factor of 2 ÷ 3 from one solution to the other.

The emergency circuit 15 consists of the elements D1, D2, LV1, C1, C3, C_LDE, R1, R2, R3 and Q1 and is connected to the light source 17 consisting of the emergency LEDs LDE1, LDE2, ..., LDEN and to the battery 16.

The emergency circuit 15 is connected in series to the input terminals of the original power supply 11 of the electronic LED bulb, between one of the input terminals and the connector of the CN1 socket of the bulb.

The emergency circuit 15 is then crossed by the input current of the power supply D_LD, a current that circulates, for the positive half-wave, in the diode D2 and in the bipole LV1 / 16 and, for the negative half-wave, through the diode D1.

The rechargeable battery 16 has a nominal voltage between 3.2V and 4V and can be made up of a series of 3 nominal 1.2V elements (of the NiCd or NiMH type) or of a single lithium ion element (for example with nominal voltages of 3.2V, 3.6V or 3.7V) or by other technological solutions with voltages between 3.2V and 4V.

The emergency circuit 15 is governed by the programmable element C_LDE, which includes the microcontroller M1 with amplifier and integrated analog converter. The programmable element C_LDE is powered directly by the battery 16 to which it is connected in parallel.

The microcontroller M1 measures the alternating voltage present on the CN1 socket of the bulb by means of the capacitor C1 and consequently drives the emergency LEDs LDE1, LDE2,…, LDEN, controlling the bipolar transistor Q1.

The microcontroller M1 is able to generate bursts of square waves at a frequency of a few hundred Hz on the output connected to the R3, C3 network for measuring the input impedance of the bulb.

This output can also be driven in high impedance during the measurement periods of the bulb input voltage.

In the presence of the AC mains power supply at the two ends of the CN1 socket (corresponding to the terminals 12 of the lamp holder 13), the alternating input current passes through D1 and D2 and circulates at the input of the ordinary power supply 11; the LD1, LD2,…, LDN of the light source 10 are regularly switched on. The current that circulates through D2 for half a wave recharges the battery 16, while the voltage across the battery 16 increases during the recharging operation up to the maximum allowable value determined by the LV1 shunt voltage regulator.

This LV1 regulator intervenes by shunting the recharging current when the voltage reaches the maximum set value, for example 4.2V (for lithium ion batteries), protecting the battery 16 from damage due to excessive charging.

The voltage drop introduced by the battery 16 for this function is negligible for the light bulb; in fact, at the ends of the battery 16 are located at most 4.2V, which, added to the voltage drop of the diode D2 (equal to 0.6V), make a total of 4.8V; therefore, even in the most unfortunate case of mains voltage equal to 110Vac, with Vpeak = 155V, this voltage drop affects the reduction of the input voltage of the power supply 11 of the bulb by about 3%. In the case of voltage of 230Vac and Vpeak = 325V, the reduction in voltage at the input of the power supply 11 caused by recharging the battery 16 is even more negligible, of the order of 1.5%.

The LV1 shunt regulator is of the type characterized by negligible current consumption at the rated operating voltage of the battery 16.

The programmable element C_LDE, correctly powered by the battery 16, measures the alternating voltage across D1 by means of the capacitor C1 and its A / D converter and, verifying the presence of an alternating voltage M at the mains frequency F of peak amplitude. peak higher than the battery voltage 16 and with a shape and amplitude higher than the threshold S2, it detects the presence of the mains and keeps the emergency LEDs LDE1, LDE2,…, LDEN of the source 17 off, switching off the transistor Q1.

The LV1 shunt regulator, which shunts the battery 16 regardless of its state when the maximum permitted voltage is exceeded, advantageously allows the bulb to operate in the ordinary way even in the event that the battery 16, as it ages, is no longer able to absorb the charging current. . Obviously in the event of a short circuit of the battery 16 the emergency part ceases to function but the normal operation of the power supply 11 is guaranteed.

The bulb therefore retains the function of a normal ordinary lighting bulb even in the event of complete damage to the battery 16.

In the presence of the power supply with the switch I of the circuit external to the light bulb (fig. 1-4) off, the light bulb does not receive the energy necessary for the operation of the ordinary power supply 11; the current in the input circuit of the light bulb is practically zero and the battery 16 does not recharge.

The C_LDE emergency condition monitoring and management element is powered by battery 16; the power consumption is very low, limiting itself on average to a few tens of µA, in fact the M1 microcontroller limits its activity to periods of ignition interspersed with periods of "sleep", with a periodicity of a few tens of ms.

During the periods of activity, the microcontroller M1 measures the voltage present across D1 by means of the capacitor C1 and its own A / D converter.

The microcontroller M1 processes the alternating voltage measured across D1 with a digital filter and compares the measured value with the two thresholds S1 and S2; in particular, the threshold S1 can be predefined or pre-calculated to decide whether or not to turn on the LEDs LDE1, LDE2,…, LDEN of the emergency light source 17 at full power, by driving the transistor Q1.

If the AC signal, at the mains frequency F (50 or 60 Hz), across D1 is higher than threshold S1 and lower than threshold S2 (signal M in fig. 12), the microcontroller M1, depending on how it has been configured at the factory can behave in one of the following ways:

- normal mode, according to which M1 keeps transistor Q1 off and consequently the emergency LEDs LDE1, LDE2,…, LDEN;

- "step-by-step" mode, according to which M1 drives the LDE1, LDE2, ..., LDEN emergency LEDs with PWM modulation and duty-cycle of the order of 1% to keep battery consumption 16 very low and provide a very low intensity and orientation in very dark rooms (in this case not much energy is taken from the battery 16 and the duration in the event of a real emergency is not significantly reduced).

Conversely, if the measured AC voltage is lower than the threshold S1, the microcontroller M1 goes into state C of fig. 13, turns on transistor Q1 and consequently the emergency LEDs LDE1, LDE2,…, LDEN.

At the same time, the microcontroller M1 activates the measurement of the impedance of the power supply circuit of the light bulb.

The alternating voltage at the ends of D1 coincides, with switch I off (open), with the residual alternating voltage AC at the ends of the socket CN1 of the bulb.

In the absence of mains voltage on the socket CN1 of the bulb, the diodes D1 and D2 are cut off and show a high impedance; in this condition the microcontroller M1 can measure, thanks to its own high input impedance amplifier and through C1, the residual voltage across CN1.

The input of the power supply 11 behaves in the measurement series circuit as a low impedance bipole at the network frequency F, not introducing attenuation of the alternating voltage to be measured present on the CN1 socket and seen at the ends of D1.

A circuit architecture has therefore been realized in a simple and advantageous manner which allows the high impedance measurement of the residual voltage across the socket CN1 of the light bulb in a universal and effective way, with the light bulb off.

The measurement of the voltage at the input of the bulb for determining the operating mode and the state of the switch I and the presence of AC power supply upstream is only possible if the bulb itself behaves like a high impedance bipole; it is not possible to carry out the measurement with a low impedance measurement circuit.

Any other emergency lamp made in such a way as to have a low input impedance is unable to make a correct measurement of the input voltage with switch I open.

In fact, the input impedance of the bulb is placed in series with the parasitic impedance of the switch I which has a very high modulus; therefore, the only way to measure an appreciable signal to be compared with the S1 and S2 thresholds is to create a high impedance measurement circuit (with Mohm-order module).

The circuit of fig. 7 achieves this feature in a very advantageous way, since it does not place restrictions on the ordinary power supply part of the light bulb (power supply 11), which, in general, is characterized by a low impedance; furthermore, the circuit of fig. 7 conveniently provides that this power supply part 11 is put in series with the measurement circuit, thus not affecting the reduction of the input impedance of the measurement circuit.

This unlike other measurement methods, such as the one mentioned in the prior patent document GB2501770A, which, on the contrary, is not able to carry out measurements with a sufficiently high input impedance, despite the introduction of the Zener 73 (fig. 5, pages 8-17 of GB2501770A), due to the presence of capacitor 75 (fig. 5, pag. 8-17 of GB2501770A), which, functional for the purposes of this prior document, excessively reduces the input impedance for the purposes of the present invention. In fact, this capacitor will necessarily have a value of a few thousand pF (as its function is described in the prior document GB2501770A), which almost completely cancels the signal that can be coupled to the input of the bulb by means of the parasitic capacitance of the switch I ( which is of the order of pF), making it impossible to evaluate the thresholds S1, S2.

According to the present invention, the determination of the threshold S1 of the microcontroller M1 can take place in two distinct ways:

1. the threshold is factory pre-set at a value determined following experimental setups and cannot be changed during operation;

2. the threshold is automatically determined by the light bulb in a self-adaptive way during operation; in this case, the bulb leaves the factory with a predetermined value and automatically adapts to the operating conditions on the system (this operating mode can be useful for managing the cases of systems in which the measured AC signal levels have a very wide dynamic; for example in the case of fig. 1 the AC input voltage is very low, unlike the case of fig. 2 or fig. 4 in which the AC voltage can be much higher).

The self-adaptive threshold bulb works as follows: the bulb leaves the factory with a predetermined threshold value (S1 = VL) and, when the switch I is turned off for the first time, the microcontroller Mi measures the AC voltage signal on Di and , based on the value of the measure, defines the following actions:

• if the AC voltage is lower than VL, it is an emergency condition and therefore the bulb turns on in an emergency;

• if the voltage is between VLe the maximum value VH, the new threshold Si has been redefined equal to 2/3 of the measured value.

In this way it is possible to improve the immunity of the bulb, ensuring that, even in the presence of a residual AC voltage spurious (and also in the absence of the 230V power supply of the system caused by any interference from adjacent systems), the bulb activates correctly the emergency function.

The microcontroller Mi activates the measurement of the impedance of the circuit upstream of the light bulb only in the appropriate operating states (states C, D, E of the diagram in fig. 13) and when the measurement is activated the operation is as follows.

The microcontroller Mi periodically generates square wave bursts at a frequency of a few hundred Hz on its output connected to resistor R3.

This test signal is coupled to the ends of D2 by means of the R3, C3 series network and from here to the ends of the connector of the socket CN1, by means of the low impedance of the power supply circuit 11 and, in particular, of the capacitor C2.

The impedance of the circuit upstream of the CN1 socket determines the amplitude of the signal generated by the microcontroller M1 at the ends of CN1.

In fact, if the switch I is open, the signal at the ends of CN1 generated by the microcontroller M1 is found practically unchanged, while if the switch I is closed, this signal is strongly attenuated by the impedance of the power supply network, which usually has very high values. low (few Ohms).

The microcontroller M1, using the amplifier and the analog to digital converter connected to C1, measures the amplitude of the signal reflected at the ends of CN1 and therefore at the ends of D1 and is therefore able to determine the impedance module of the power supply circuit. of the light bulb, since if the voltage measured by C1 across D1 is high the impedance is high and, vice versa, if the measured voltage is low so is the impedance.

The microcontroller M1, in particular, is programmed to distinguish variations in impedance and if the voltage of the last generated burst, measured across C1, is higher than the reflected voltage of the previously generated burst, this is equivalent to a positive impedance transition ( increase in impedance, from LOW to HIGH, fig. 13).

Conversely, if the voltage of the last generated burst, measured through C1, is lower than the reflected voltage of the previously generated burst, this is equivalent to a negative impedance transition (decrease in impedance, from HIGH to LOW, fig. 13).

A very simple and very low cost method was therefore created for measuring this impedance using the advantage of the series connection of the ordinary power supply part (portion D_LD of the power supply 11), without the need to complicate the bulb circuit (as in the patent documents of known art).

In the event that several bulbs are connected in parallel with each other and controlled by the same switch I, all the functions described continue to work correctly, in particular if the number of bulbs connected in parallel is not excessively high and does not reduce the overall impedance too much. of the measuring circuit.

In general, up to 5-10 bulbs are not a problem.

To prevent the impedance measurements operated by the various bulbs from influencing each other in this configuration, each bulb emits measurement bursts with random periodicity in order to avoid signal overlap as much as possible.

The identification of an impedance transition takes place by validating the measurements of several consecutive bursts, in order to reduce the probability of incorrect activations to a negligible entity.

The LEDs dedicated to the emergency LDE1, LDE2, ..., LDEN, which make up the emergency light source 17, are advantageously driven by the bipolar transistor Q1, minimizing the cost and effectiveness of the driving circuit.

In fact, the correct combination of the battery voltage (3.2-3.7 Volt, depending on the technology chosen for the battery) and the LEDs used and the small powers involved for the emergency application, allows you to use a connection practically direct with the battery 16, in which the resistance R2, of small value, limits, together with the internal resistance of the battery 16, the maximum current that can be supplied with the battery fully charged.

The discharge of the battery 16, progressively reducing the voltage, causes the current in the LEDs of the emergency light source 17 to drop naturally over time, with the perfect application result of a slow reduction in brightness, which, although not perceived by the eye of the observer, allows the autonomy of the emergency function to be extended to the maximum possible time, optimizing use of the battery 16.

The apparent simplicity of the circuit does not sacrifice the electrical efficiency, which is very high since the nominal voltage of the battery 16 is close to the operating voltage of the LEDs of the source 17.

Any switching converter would have a lower efficiency for the small powers involved.

The microcontroller M1 is however able to vary the driving duty-cycle of Q1, in order to further modulate the intensity of the average current absorbed by the battery 16, in order to optimally exploit the available energy.

The PWM modulation frequency in this case is in the order of 20 ÷ 30 KHz.

The light bulb according to the invention is also equipped with an emergency mode inhibition function (function called "rest-mode").

In practice, the microcontroller M1 analyzes, by means of the AC voltage measured on D1, the sequence of consecutive lighting of the light bulb (i.e. the on and off sequences of switch I) and, if the user switches the light on and off consecutively for 4 times interspersed, in a regular manner by pauses and switch-ons lasting about 3 seconds each, the microcontroller M1 interprets this sequence as a command to inhibit the emergency signal.

From the last of the four shutdowns the light bulb goes into the inhibited state and, at this point, the light bulb can be uninstalled (removed from the lamp holder 13) without turning on in an emergency, preserving the battery charge 16.

The M1 microcontroller is placed in a condition of very low consumption, preserving the state of charge of the battery 16 to the maximum.

At the first subsequent restart of switch I (ie when the light bulb is re-powered to the mains voltage) the inhibition is immediately removed and the light bulb restores its normal operation with the emergency function activated.

The inhibition function is convenient for the user to carry the bulb and also to preserve the charge of the battery 16 after the bulb itself has been built in the factory, before sale and delivery to customers.

The figs. 8 and 9 attached illustrate a possible industrial application of the universal emergency circuit of fig. 7 and battery 16 to a 3.5W olive LED bulb; in figs. 8 and 9 also show a possible embodiment of a flexible circuit 18 where the LEDs of the ordinary lighting source 10 and the LEDs of the emergency lighting source 17 are mounted (in particular, the LEDs are mounted isolated on a glued flexible printed circuit to an aluminum support).

It is evident that the simplicity and possibility of miniaturization of the circuit easily allow integration even in the smallest forms, making it convenient to extend the emergency lighting function to all commercial light bulbs.

The figs. 10 and 11 illustrate a possible industrial application of the universal emergency circuit 15 and of the battery 16 to an E27 filament LED bulb.

Finally, it is possible to apply the circuit of fig.

7 also to a universal lamp holder 13, in which only the emergency part is inserted and on which any commercial light bulb can be screwed.

The described solution can also be integrated with any type of non-LED electronic bulb, for example of the compact fluorescent CFL type.

The reference diagrams for this type of integration are those of fig. 6 and 7, in which the LED power supply is replaced by a compact fluorescent tube (CFL) power supply and the LED source is replaced by the fluorescent tube itself.

The C_LDE emergency power supply, the battery 16 and the LDE1, LDE2, ... LDEN LEDs of the emergency light source 17 remain in this case the same as in the case of application to the LED bulb.

From the description made, the characteristics of the lighting apparatus with built-in circuit for emergency lighting, which is the subject of the present invention, are clear, as are the advantages.

Finally, it is clear that numerous other variations can be made to the lighting fixture in question, without thereby departing from the principles of novelty of the inventive idea, just as it is clear that, in the practical implementation of the invention, the materials, the shapes and the dimensions of the illustrated details can be any according to requirements and the same can be replaced with other technically equivalent ones.

Claims (10)

CLAIMS 1. Luminaire with incorporated circuit for emergency lighting, comprising an electronic bulb equipped with a first light source (10) necessary for ordinary lighting, which is connected to a power supply (11) connected in turn to the mains power supply, and an emergency circuit (15), connected in series to said power supply (11), which includes an emergency battery (16) and a second light source (17) necessary for emergency lighting, said circuit emergency (15) including a management and control element (C_LDE), equipped with a microcontroller (M1), which is powered by said emergency battery (16) and which analyzes the trend over time of the voltage across the terminals power supply of the light bulb and compares it with at least two stored threshold trends (S1, S2), of which a first minimum threshold trend (S1) and a second maximum threshold trend (S2), identifying a lighting condition emergency action and distinguishing it from a condition according to which a switch or disconnector (I) of one of the two conductors that power said bulb is open, so that said bulb, - in the presence of power supply, turns on with full light and at the same time recharging the emergency battery (16), - turns off and goes into a stand-by state, while the recharging of said emergency battery (16) ceases, if said switch (I) is open, - turns on in emergency with reduced light using said battery (16) emergency if there is no voltage on the circuit upstream of said switch (I), characterized by the fact that said microcontroller (M1) of the emergency circuit (15) commands: - a switching on of said second light source (17), if said voltage at the ends of the power supply terminals of the bulb has, in a determined period of time, a profile lower than said first minimum threshold trend (S1), - a switching off or switching on at reduced intensity of the second light source (17), if said voltage at the ends of the power supply terminals has, in a determined period of time, a profile (M) included between said first minimum threshold trend (S1 ) and said second trend of maximum threshold (S2), - a switching off of said second light source (17), if said voltage across the power supply terminals has, in a determined period of time, a profile higher than said second maximum threshold trend (S2). 2. Lighting device as in claim 1, characterized in that when said microcontroller (M1) of the emergency circuit (15) detects a state (C) of absence of voltage upstream of said switch (I) it commands an ignition of said second emergency light source (17) and performs an impedance measurement upstream of the bulb, so that: - if said switch (I) was open at the time of said emergency switch-on, a first maneuver of said switch (I) from open to closed causes a first transition from high impedance to low impedance upstream of the bulb and said microcontroller (M1) keeps the second light source (17) on (D), - if a second operation of said switch (I) takes place from closed to open, said microcontroller (M1) detects a second transition from low impedance to high impedance upstream of the bulb and controls the switching off (E) of the second light source (17), - if a third operation of said switch (I) takes place from open to closed, said microcontroller (M1) detects a third transition from high impedance to low impedance upstream of the bulb and commands a re-ignition of said second light source (17). 3. Lighting device as in claim 2, characterized in that, in the case in which said voltage across the terminals of the bulb is higher, in a determined period of time, than said first minimum threshold trend (S1), said microcontroller (M1) ceases said impedance measurement and commands a shutdown (A) of said second emergency light source (17). 4. Lighting device as in claim 2, characterized in that, if said switch (I) was closed at the time of said emergency ignition, a first maneuver of said switch (I) from closed to open causes an increase in impedance upstream of said bulb and said microcontroller (M1) it controls a shutdown of said second emergency light source (17). 5. Lighting apparatus as per at least one of the preceding claims, characterized in that said microcontroller (M1) controls an emergency shutdown of said second light source (17) when the voltage of said battery (16) falls below a minimum preset value. 6. Lighting device as per at least one of the preceding claims, characterized in that said power supply (11) for ordinary lighting has an input current alternating with the mains frequency, the intensity of which is proportional to the power absorbed by the bulb, while the direct output current is adjusted to a value necessary for powering said first light source (10) for ordinary lighting. 7. Lighting device as per at least one of the preceding claims, characterized in that said first and second light sources (10, 17) each comprise a plurality of LEDs (LD1, LD2, ..., LDN; LDE1, LDE2, ..., LDEN ). 8. Lighting device as per at least one of the preceding claims, characterized in that said emergency circuit (15) is connected in series to the input terminals of said power supply (11), between one of said input terminals and an electrical connector associated with a socket (CN1) of the bulb. 9. Lighting device as per at least one of the preceding claims, characterized in that said first minimum threshold trend (S1) is pre-set and cannot be modified or is automatically determined by the bulb, through said microcontroller (M1), during operation , starting from a predetermined value. 10. Lighting device as per at least one of the preceding claims, characterized in that said microcontroller (M1) analyzes a sequence of consecutive switching on of the light bulb, so that, if said light bulb is switched on and off consecutively 4 times at regular intervals , said microcontroller (M1) controls a shutdown of said second emergency light source (17) and places said bulb in a state of inhibition, in order that said bulb can be uninstalled without turning on in emergency.