Patent Publication Number: US-2022235907-A1

Title: Linear Solid-State Lighting With Bidirectional Circuits

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present disclosure is part of a continuation-in-part (CIP) application of U.S. patent application Ser. No. 17/696,780, filed 16 Mar. 2022, which is part of CIP application of U.S. patent application Ser. No. 17/405,203, filed 18 Aug. 2021 and issued as U.S. Pat. No. 11,283,291 on 22 Mar. 2022, which is part of CIP application of U.S. patent application Ser. No. 17/329,018, filed 24 May 2021, which is part of CIP application of U.S. patent application Ser. No. 17/313,988, filed 6 May 2021 and issued as U.S. Pat. No. 11,264,831 on 1 Mar. 2022, which is part of CIP application of U.S. patent application Ser. No. 17/213,519, filed 26 Mar. 2021 and issued as U.S. Pat. No. 11,271,422 on 8 Mar. 2022, which is part of CIP application of U.S. patent application Ser. No. 17/151,606, filed 18 Jan. 2021 and issued as U.S. Pat. No. 11,259,386 on 22 Feb. 2022, which is part of CIP application of U.S. patent application Ser. No. 17/122,942, filed 15 Dec. 2020 and issued as U.S. Pat. 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No. 14/465,174, filed 21 Aug. 2014 and issued as U.S. Pat. No. 9,277,603 on 1 Mar. 2016, which is a CIP application of U.S. patent application Ser. No. 14/135,116, filed 19 Dec. 2013 and issued as U.S. Pat. No. 9,163,818 on 20 Oct. 2015, which is a CIP application of U.S. patent application Ser. No. 13/525,249, filed 15 Jun. 2012 and issued as U.S. Pat. No. 8,749,167 on 10 Jun. 2014. Contents of the above-identified applications are incorporated herein by reference in their entirety. 
    
    
     BACKGROUND 
     Technical Field 
     The present disclosure relates to linear light-emitting diode (LED) lamps and more particularly to a linear LED lamp that includes a bidirectional circuit and a self-diagnostic circuit to operate thereof and to auto-test charging and discharging current of a rechargeable battery in operating such a dual mode LED lamp at all times. 
     Description of the Related Art 
     Solid-state lighting from semiconductor LEDs has received much attention in general lighting applications today. Because of its potential for more energy savings, better environmental protection (with no hazardous materials used), higher efficiency, smaller size, and longer lifetime than conventional incandescent bulbs and fluorescent tubes, the LED-based solid-state lighting will be a mainstream for general lighting in the near future. Meanwhile, as LED technologies develop with the drive for energy efficiency and clean technologies worldwide, more families and organizations will adopt LED lighting for their illumination applications. In this trend, the potential safety concerns such as risk of electric shock and fire become especially important and need to be well addressed. 
     In today&#39;s retrofit applications of an LED lamp to replace an existing fluorescent lamp, consumers may choose either to adopt a ballast-compatible LED lamp with an existing ballast used to operate the fluorescent lamp or to employ an alternate-current (AC) mains-operable LED lamp by removing/bypassing the ballast. Either application has its advantages and disadvantages. In the former case, although the ballast consumes extra power, it is straightforward to replace the fluorescent lamp without rewiring, which consumers have a first impression that it is the best alternative. But the fact is that total cost of ownership for this approach is high regardless of very low initial cost. For example, the ballast-compatible LED lamps work only with particular types of ballasts. If the existing ballast is not compatible with the ballast-compatible LED lamp, the consumer will have to replace the ballast. Some facilities built long time ago incorporate different types of fixtures, which requires extensive labor for both identifying ballasts and replacing incompatible ones. Moreover, the ballast-compatible LED lamp can operate longer than the ballast. When an old ballast fails, a new ballast will be needed to replace in order to keep the ballast-compatible LED lamps working. Maintenance will be complicated, sometimes for the lamps and sometimes for the ballasts. The incurred cost will preponderate over the initial cost savings by changeover to the ballast-compatible LED lamps for hundreds of fixtures throughout a facility. In addition, replacing a failed ballast requires a certified electrician. The labor costs and long-term maintenance costs will be unacceptable to end users. From energy saving point of view, a ballast constantly draws power, even when the ballast-compatible LED lamps are dead or not installed. In this sense, any energy saved while using the ballast-compatible LED lamps becomes meaningless with the constant energy use by the ballast. In the long run, the ballast-compatible LED lamps are more expensive and less efficient than self-sustaining AC mains-operable LED lamps. 
     On the contrary, an AC mains-operable LED lamp does not require a ballast to operate. Before use of the AC mains-operable LED lamp, the ballast in a fixture must be removed or bypassed. Removing or bypassing the ballast does not require an electrician and can be replaced by end users. Each AC mains-operable LED lamp is self-sustaining. Once installed, the AC mains-operable LED lamps will only need to be replaced after 50,000 hours. In view of above advantages and disadvantages of both the ballast-compatible LED lamps and the AC mains-operable LED lamps, it seems that market needs a most cost-effective solution by using a universal LED lamp that can be used with the AC mains and is compatible with a ballast so that LED lamp users can save an initial cost by changeover to such an LED lamp followed by retrofitting the lamp fixture to be used with the AC mains when the ballast dies. 
     Furthermore, the AC mains-operable LED lamps can easily be used with emergency lighting, which is especially important in this consumerism era. The emergency lighting systems in retail sales and assembly areas with an occupancy load of 100 or more are required by codes in many cities. Occupational Safety and Health Administration (OSHA) requires that a building&#39;s exit paths be properly and automatically lighted at least ninety minutes of illumination at a minimum of 10.8 lux so that an employee with normal vision can see along the exit route after the building power becomes unavailable. This means that emergency egress lighting must operate reliably and effectively during low visibility evacuations. To ensure reliability and effectiveness of backup lighting, building owners should abide by the National Fire Protection Association&#39;s (NFPA) emergency egress light requirements that emphasize performance, operation, power source, and testing. OSHA requires most commercial buildings to adhere to the NFPA standards or a significant fine. Meeting OSHA requirements takes time and investment, but not meeting them could result in fines and even prosecution. If a building has egress lighting problems that constitute code violations, the quickest way to fix is to replace existing lamps with multi-function LED lamps that have an emergency light package integrated with the normal lighting. The code also requires the emergency lights be inspected and tested to ensure they are in proper working conditions at all times. It is, therefore, the manufacturers&#39; responsibility to design an LED lamp, an LED luminaire, or an LED lighting system with a self-diagnostic mechanism such that after the LED lamp or the LED luminaire is installed on a ceiling or a high place in a room, the self-diagnostic mechanism can work with an emergency battery backup system to periodically auto-test charging and discharging current to meet regulatory requirements without safety issues. In the emergency battery backup system, an essential part is controlling a forward electric current and a reverse electric current to and from a rechargeable battery to properly operate the multi-function LED lamps with the emergency light package integrated with the normal lighting. 
     SUMMARY 
     A linear LED lamp is used to replace a fluorescent or an LED lamp normally operated with the AC mains in a normal mode. The linear LED lamp comprises an emergency-operated portion and one or more LED arrays with a forward voltage across thereof. The emergency-operated portion comprises a rechargeable battery, a boost converter circuit configured to use a power from the rechargeable battery and to provide an emergency power (i.e., a voltage and a current) to drive the one or more LED arrays when the line voltage from the AC mains is unavailable. The linear LED lamp further comprises a normally-operated portion originally designed to receive the line voltage from the AC mains for general lighting applications. The normally-operated portion comprises at least two electrical conductors “L” and “N”, at least one full-wave rectifier, and a fly-back converter circuit. The at least one full-wave rectifier is configured to convert the line voltage from the AC mains into a primary direct-current (DC) voltage. In other words, the at least two electrical conductors “L” and “N” are coupled to an un-switched power, in which the normally-operated portion cannot be turned off when the linear LED lamp is not in use or during nighttime. This un-switched power ensures that the rechargeable battery always receives the un-switched power from the line voltage. The fly-back converter circuit comprises a transformer and a power switching circuit. The power switching circuit is coupled to the at least one full-wave rectifier and configured to allow the fly-back converter circuit  303  to generate a second LED driving current to power up the one or more LED arrays at a full power when the line voltage is available. The transformer comprises a ground reference, electrically isolated from a negative (−) port of the at least one full-wave rectifier. The one or more LED arrays comprises a first terminal LED+ and a second terminal LED− configured to receive an LED driving current from the first terminal LED+ and to return from the second terminal LED− to either the boost converter circuit or the normally-operated portion, depending on which one is an LED driving current source. The fly-back converter circuit is a normally-operated current source configured to provide the second LED driving current to the one or more LED arrays to operate thereon. 
     The emergency-operated portion is configured to receive the primary DC voltage via a diode. The emergency-operated portion further comprises a primary control circuit, a bidirectional circuit, and a major power source configured to pre-powers the emergency-operated portion. The bidirectional circuit is configured to receive a power from the major power source via a port “A”. The rechargeable battery comprises a high-potential electrode and a low-potential electrode with a terminal voltage across thereon. The major power source is an isolated step-down converter configured to convert the primary DC voltage into a second DC voltage that charges the rechargeable battery to reach a nominal value of the terminal voltage. Please note that the terminal voltage of the rechargeable battery may be slightly less than the nominal value because the rechargeable battery ages or an ambient temperature is below an optimum operating temperature. When the rechargeable battery badly ages or goes wrong, the terminal voltage may be far from the nominal value. That is why the rechargeable battery test is needed to ensure that the rechargeable battery is working all the time, especially in an event of power outage. The bidirectional circuit comprises one or more electronic switches configured to control a forward electric current and a reverse electric current to and from the rechargeable battery. In the bidirectional circuit, the one or more electronic switches comprise a first electronic switch and a second electronic switch. The first electronic switch is configured to receive a first set of one or more signals from the primary control circuit via a link to regulate the forward electric current to the rechargeable battery via the second electronic switch. The primary control circuit further comprises a test portion configured to examine a fraction of the terminal voltage on the rechargeable battery. When a rated terminal voltage is reached, the primary control circuit is configured to disable a charging process via the bidirectional circuit. Conversely. when the terminal voltage drops below the rated terminal voltage, the primary control circuit is configured to enable a charging process via the bidirectional circuit. The primary control circuit may further comprise a line-voltage monitor configured to detect whether the line voltage is available or not. According to this information, the primary control circuit is configured to enable and to disable the boost converter circuit. Enabling the boost converter circuit comprises two processes. First, the bidirectional circuit must control the reverse electric current from the rechargeable battery to reach the boost converter circuit via a link. Second, the primary control circuit must send a logically-high level signal to the boost converter circuit via a port “C”. The ground reference is electrically coupled to the low-potential electrode to ease a charging current to flow into the rechargeable battery and to return to the major power source, completing a power transfer. 
     The primary control circuit comprises a second control circuit comprising a third electronic switch and a fourth electronic switch. The third electronic switch and the fourth electronic switch are configured to control whether the second LED driving current is supplied into the one or more LED arrays or not. The third electronic switch is configured to turn on the fourth electronic switch, thereby allowing the second LED driving current to flow into the one or more LED arrays. The second control circuit may further comprise a signaling device configured to enable and disable the fly-back converter circuit via a link. That is, when the boost converter circuit is turned on by the primary control circuit, the signaling device sends a signal to turn off the fly-back converter circuit, and vice versa. The fourth electronic switch may comprise a first at least one metal-oxide-semiconductor field-effect transistor (MOSFET) configured to couple between the fly-back converter circuit and the one or more LED arrays and to controllably relay the second LED driving current to reach the one or more LED arrays via a loop from a port, a down-link, the fourth electronic switch, an uplink, to the port of LED+. The third electronic switch may comprise at least one bipolar junction transistor (BJT) coupled to the first at least one MOSFET and configured to receive the logic high level or the logic low level to respectively turn the first at least one MOSFET on or off. When the first at least one MOSFET is turned off, the second LED driving current is interrupted with an output of the fly-back converter circuit open-circuited. The second control circuit may be configured to forbid the second LED driving current to flow into the one or more LED arrays during the rechargeable battery test. 
     The primary control circuit further comprises a self-diagnostic circuit comprising one or more timers. Each of the one or more timers respectively comprises multiple time delays, wherein the multiple time delays respectively further comprise a first time delay and a second time delay, wherein, upon an initiation of each of the one or more timers, the first time delay begins with an input voltage applied on the self-diagnostic circuit, wherein, at an end of the first time delay, the output of the self-diagnostic circuit is activated to reach the logic high level and remains activated so as to enable the boost converter circuit for the second time delay, wherein, at an end of the second time delay, the output of the self-diagnostic circuit is inactivated to drop to the logic low level to disable the boost converter circuit, and wherein a duration over the second time delay is configured to allow the self-diagnostic circuit to integrate with the test portion and to perform a rechargeable battery test. When the rechargeable battery test is initiated, the second control circuit is configured to forbid the second LED driving current to flow into the one or more LED arrays. The primary control circuit further comprises a peripheral circuit configured to sample a fraction of the LED forward voltage and to deliver to the test portion to examine over the duration of the next time delay when the rechargeable battery test is initiated. The primary control circuit further comprises at least one status indicator configured to show a result of the rechargeable battery test. The primary control circuit further comprises a test switch configured to manually initiate the rechargeable battery test. When the rechargeable battery test is manually initiated, the self-diagnostic circuit is configured to ignore the first time delay and to activate the output of the self-diagnostic circuit to reach the logic high level and remains activated so as to enable the boost converter circuit for the second time delay, wherein, at an end of the second time delay, the output of the self-diagnostic circuit is inactivated to drop to the logic low level to disable the boost converter circuit, and wherein a duration over the second time delay is configured to allow the self-diagnostic circuit to integrate with the test portion and to perform a rechargeable battery test, as mentioned above. The test switch is further configured to manually cause or trigger the self-diagnostic circuit to terminate the rechargeable battery test that is in progress. The emergency-operated portion may further comprise a voltage regulator configured to adapt either an output voltage from the major power source or the terminal voltage to an operating voltage of the primary control circuit to operate thereof. An operation of the voltage regulator involves a power switching between the major power source and the rechargeable battery via the bidirectional circuit. 
     The boost converter circuit comprises one or more switches, an inductor, a boost control circuit, and at least one capacitor. The boost converter circuit is configured to cut off a constant source of power from the rechargeable battery into controllable increments of energy pulses, followed by a filter associated with the at least one capacitor to rebuild the controllable increments of energy pulses back into a regulated source of usable output power providing a first LED driving current to drive the one or more LED arrays. The boost converter circuit may comprise a diode configured to block an output current when the one or more switches is closed. When the one or more switches is opened, the diode is configured to conduct the output current and to boost an output voltage greater than the forward voltage of the one or more LED arrays. In this sense, the diode may function as a switch. The one or more switches may include such a switch. See  FIG. 5  for further discussions. An output port “B” of the boost converter circuit is directly coupled to LED+. This means that the one or more LED arrays is configured to receive the first LED driving current from the boost converter circuit as long as the boost converter circuit is enabled and operated. 
     In a second embodiment of the linear LED lamp, the bidirectional circuit further comprises a first control circuit configured to regulate the forward electric current to flow into the rechargeable battery. The one or more electronic switches comprise a first set of one or more electronic switches and a second set of one or more electronic switches. The forward electric current is allowed to flow into the rechargeable battery via the second set of one or more electronic switches. The first set of one or more electronic switches are configured to receive a second set of one or more signals sent from the primary control circuit and to allow the reverse electric current to flow out of the rechargeable battery. The second set of one or more electronic switches comprise at least one transistor circuit configured to activate the boost converter circuit. In other words, the bidirectional circuit is configured to receive the second set of one or more signals from the primary control circuit and to allow the reverse electric current to flow out of the rechargeable battery and to apply the terminal voltage to the boost converter circuit to supply with energy and power up the boost control circuit to activate the boost converter circuit via a port “D”. 
     In a third embodiment of the linear LED lamp, the major power source is configured to receive a power from a second full-wave rectifier, taking advantages of two independent power sources from two different full-wave rectifiers such that the normally-operated portion can be turned off at any time without affecting functionality of the emergency-operated portion. The normally-operated portion comprises at least two electrical conductors “L′” and “N”, a first full-wave rectifier, and the fly-back converter circuit. The at least two electrical conductors “L” and “N” are configured to couple to “L” and “N” via a power switch. The first full-wave rectifier is configured to convert the line voltage from the AC mains into a primary DC voltage. In other words, the at least two electrical conductors “L” and “N” are coupled to a switched power, in which the normally-operated portion can be turned off when the linear LED lamp is not in use any time 
     The linear LED lamp further comprises a first end and a second end opposite to the first end. The first full-wave rectifier and the second full-wave rectifier are configured to independently receive the line voltage. Either of the first end and the second end comprises at least two electrical conductors, wherein each of the at least two electrical conductors is respectively coupled to the first full-wave rectifier and the second full-wave rectifier. The second full-wave rectifier is configured to power the major power source at all times. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Non-limiting and non-exhaustive embodiments of the present disclosure are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various figures unless otherwise specified. Moreover, in the section of detailed description of the invention, any of a “main”, a “primary”, a “secondary”, a “preliminary”, an “initial”, a “first”, a “second”, a “third”, and so forth does not necessarily represent a part that is mentioned in an ordinal manner, but a particular one. 
         FIG. 1  is a block diagram of a linear LED lamp according to the present disclosure. 
         FIG. 2  is a second embodiment of the linear LED lamp according to the present disclosure. 
         FIG. 3  is a third embodiment of the linear LED lamp according to the present disclosure. 
         FIG. 4  is a timing diagram of a self-diagnostic circuit according to the present disclosure. 
         FIG. 5  is controllable increments of energy pulses and a regulated source of usable output power providing a first LED driving current according to the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a block diagram of a linear light-emitting diode (LED) lamp according to the present disclosure. A linear LED lamp  110  is used to replace a fluorescent or an LED lamp normally operated with the AC mains in a normal mode. In  FIG. 1 , the linear LED lamp  110  comprises an emergency-operated portion  810  and one or more LED arrays  214  with a forward voltage across thereof. The emergency-operated portion  810  comprises a rechargeable battery  500 , a boost converter circuit  760  configured to use a power from the rechargeable battery  500  and to provide an emergency power (i.e., a voltage and a current) to drive the one or more LED arrays  214  when the line voltage from the AC mains is unavailable. The linear LED lamp  110  further comprises a normally-operated portion  311  originally designed to receive the line voltage from the AC mains for general lighting applications. The normally-operated portion  311  comprises at least two electrical conductors “L” and “N”, at least one full-wave rectifier  301 , and a fly-back converter circuit  303 . The at least one full-wave rectifier  301  is configured to convert the line voltage from the AC mains into a primary DC voltage. In other words, the at least two electrical conductors “L” and “N” are coupled to an un-switched power, in which the normally-operated portion  311  cannot be turned off when the linear LED lamp  110  is not in use or during nighttime. This un-switched power ensures that the rechargeable battery  500  always receives the un-switched power from the line voltage. The fly-back converter circuit  303  comprises a transformer  304  and a power switching circuit  305 . The power switching circuit  305  is coupled to the at least one full-wave rectifier  301  and configured to allow the fly-back converter circuit  303  to generate a second LED driving current to power up the one or more LED arrays  214  at a full power when the line voltage is available. The fly-back converter circuit  303  may further comprise a rectifier  307  and additional diode  308 . The transformer  304  comprises a ground reference  256 , electrically isolated from a negative (−) port of the at least one full-wave rectifier  301 . The transformer  304  may further comprise an auxiliary winding  309  configured to provide a sustaining power and to operate the fly-back converter circuit  303 . The one or more LED arrays  214  comprises a first terminal LED+ and a second terminal LED− configured to receive an LED driving current from the first terminal LED+ and to return from the second terminal LED− to either the boost converter circuit  760  or the normally-operated portion  311 , depending on which one is an LED driving current source. The fly-back converter circuit  303  is a normally-operated current source configured to provide the second LED driving current to the one or more LED arrays  214  to operate thereon. 
     In  FIG. 1 , the emergency-operated portion  810  is configured to receive the primary DC voltage via a diode  701 . The emergency-operated portion  810  further comprises a primary control circuit  702 , a bidirectional circuit  703 , and a major power source  704  configured to couple to the at least one full-wave rectifier  301  and to build a basic DC power, pre-powering the emergency-operated portion  810 . In that sense, the major power source  704  is configured to provide a DC power to the bidirectional circuit  703  and the rechargeable battery  500 . The bidirectional circuit  703  is configured to receive the DC power from the major power source  704  via a port “A”. The rechargeable battery  500  comprises a high-potential electrode  501  and a low-potential electrode  502  with a terminal voltage across thereon. The major power source  704  is an isolated step-down converter configured to convert the primary DC voltage into a second DC voltage that charges the rechargeable battery  500  to reach a nominal value of the terminal voltage. Please note that the terminal voltage of the rechargeable battery  500  may be slightly less than the nominal value because the rechargeable battery  500  ages or an ambient temperature is below an optimum operating temperature. When the rechargeable battery  500  badly ages or goes wrong, the terminal voltage may be far from the nominal value. That is why the rechargeable battery test is needed to ensure that the rechargeable battery  500  is working all the time, even in an event of power outage. The bidirectional circuit  703  comprises one or more electronic switches  720  configured to control a forward electric current and a reverse electric current to and from the rechargeable battery  500 . In the bidirectional circuit  703 , the one or more electronic switches  720  comprise a first electronic switch  721  and a second electronic switch  722 . The first electronic switch  721  is configured to receive a first set of one or more signals from the primary control circuit  702  via a link  408  to regulate the forward electric current to the rechargeable battery  500  via the second electronic switch  722 . The primary control circuit  702  further comprises a test portion  742  configured to examine a fraction of the terminal voltage on the rechargeable battery  500 . When a rated terminal voltage is reached, the primary control circuit  702  is configured to disable a charging process via the bidirectional circuit  703 . Conversely. when the terminal voltage drops below the rated terminal voltage, the primary control circuit  702  is configured to enable a charging process via the bidirectional circuit  703 . The primary control circuit  702  may further comprise a line-voltage monitor configured to detect whether the line voltage is available or not. According to this information, the primary control circuit  702  is configured to enable and to disable the boost converter circuit  760 . In  FIG. 1 , enabling the boost converter circuit  760  comprises two processes. First, the bidirectional circuit  703  must control the reverse electric current from the rechargeable battery  500  to reach the boost converter circuit  760  via a link  407 . Second, the primary control circuit  702  must send a logically-high level signal to the boost converter circuit  760  via a port “C”. In  FIG. 1 , the ground reference  256  is electrically coupled to the low-potential electrode  502  to ease a charging current to flow into the rechargeable battery  500  and to return to the major power source  704 , completing a power transfer. 
     In  FIG. 1 , the primary control circuit  702  comprises a second control circuit  730  comprising a third electronic switch  731  and a fourth electronic switch  732 . The third electronic switch  731  and the fourth electronic switch  732  are configured to control whether the second LED driving current is supplied into the one or more LED arrays  214  or not. The third electronic switch  731  is configured to turn on the fourth electronic switch  732 , thereby allowing the second LED driving current to flow into the one or more LED arrays  214 . The second control circuit  730  may further comprise a signaling device  733  configured to enable and disable the fly-back converter circuit  303  via a link  404 . That is, when the boost converter circuit  760  is turned on by the primary control circuit  702 , the signaling device  733  sends a signal to turn off the fly-back converter circuit  303 , and vice versa. The fourth electronic switch  732  may comprise at least one metal-oxide-semiconductor field-effect transistor (MOSFET) configured to couple between the fly-back converter circuit  303  and the one or more LED arrays  214  and to controllably relay the second LED driving current to reach the one or more LED arrays  214  via a loop from a port  206 , a down-link  405 , the fourth electronic switch  732 , an uplink  406 , to the port of LED+. The third electronic switch  731  may comprise at least one bipolar junction transistor (BJT) coupled to the at least one MOSFET and configured to receive the logic high level or the logic low level to respectively turn the at least one MOSFET on or off. When the at least one MOSFET is turned off, the second LED driving current is interrupted with an output of the fly-back converter circuit  303  open-circuited. The second control circuit  730  may be configured to forbid the second LED driving current to flow into the one or more LED arrays  214  during the rechargeable battery test. 
     In  FIG. 1 , the primary control circuit  702  further comprises a self-diagnostic circuit  740  comprising one or more timers  741 . Each of the one or more timers  741  respectively comprises multiple time delays, wherein the multiple time delays of each of the one or more timers  741  respectively further comprise a first time delay and a second time delay, wherein, upon an initiation of each of the one or more timers  741 , the first time delay begins with an input voltage applied on the self-diagnostic circuit  740 , wherein, at an end of the first time delay, the output of the self-diagnostic circuit  740  is activated to reach the logic high level and remains activated so as to enable the boost converter circuit  760  for the second time delay, wherein, at an end of the second time delay, the output of the self-diagnostic circuit  740  is inactivated to drop to the logic low level, and wherein a duration over the second time delay is configured to allow the self-diagnostic circuit  740  to integrate with the test portion  742  and to perform a rechargeable battery test. When the rechargeable battery test is initiated, the second control circuit  730  is configured to forbid the second LED driving current to flow into the one or more LED arrays  214 . The primary control circuit  702  further comprises a peripheral circuit configured to sample a fraction of the LED forward voltage and to deliver to the test portion  742  to examine over the duration of the next time delay when the rechargeable battery test is initiated. The primary control circuit  702  further comprises at least one status indicator  734  configured to show a result of the rechargeable battery test. The primary control circuit  702  further comprises a test switch  735  configured to manually initiate the rechargeable battery test. When the rechargeable battery test is manually initiated, the self-diagnostic circuit  740  is configured to ignore the first time delay and to activate the output of the self-diagnostic circuit  740  to reach the logic high level and remains activated so as to enable the boost converter circuit  760  for the second time delay, wherein, at an end of the second time delay, the output of the self-diagnostic circuit  740  is inactivated to drop to the logic low level, and wherein a duration over the second time delay is configured to allow the self-diagnostic circuit  740  to integrate with the test portion  742  and to perform a rechargeable battery test, as mentioned above. The test switch  735  is further configured to manually cause or trigger the self-diagnostic circuit  740  to terminate the rechargeable battery test that is in progress. 
     The emergency-operated portion  810  may further comprise a voltage regulator  751  configured to adapt either an output voltage from the major power source  704  or the terminal voltage to an operating voltage of the primary control circuit  702  to operate thereof. An operation of the voltage regulator  751  involves a power switching between the major power source  704  and the rechargeable battery  500  via the bidirectional circuit  703 . When the rechargeable battery test is performed, the bidirectional circuit  703  controls the reverse electric current from the rechargeable battery  500  to flow at the port “A” and the voltage regulator  751  automatically receives the power from the rechargeable battery  500  to adapt the terminal voltage to the operating voltage of the primary control circuit  702  to operate thereof. In the normal mode, the forward electric current is allowed to flow into the rechargeable battery  500 . When the forward electric current appears at the port “A”, the voltage regulator  751  automatically receives the output voltage from the major power source  704  to adapt the output voltage from the major power source  704  to the operating voltage of the primary control circuit  702  to operate thereof. 
     In  FIG. 1 , the boost converter circuit  760  comprises one or more switches  764 , an inductor  761 , a boost control circuit  763 , and at least one capacitor  765 . The boost converter circuit  760  is configured to cut off a constant source of power from the rechargeable battery  500  into controllable increments of energy pulses, followed by the at least one capacitor  765  to filter and to rebuild the controllable increments of energy pulses back into a regulated source of usable output power providing a first LED driving current to drive the one or more LED arrays  214 . Specifically, the boost converter circuit  760  is configured to rebuild the controllable increments of energy pulses back into a regulated output voltage greater than the forward voltage with a first LED driving current. The boost converter circuit  760  may comprise a diode  762  configured to block an output current when the one or more switches  764  is closed. When the one or more switches  764  is opened, the diode  762  is configured to conduct the output current and to boost an output voltage greater than the forward voltage of the one or more LED arrays  214 . In this sense, the diode  762  may function as a switch. The one or more switches  764  may include such a switch. See  FIG. 5  for further discussions. In  FIG. 1 , an output port “B” of the boost converter circuit  760  is directly coupled to LED+. This means that the one or more LED arrays  214  is configured to receive the first LED driving current from the boost converter circuit  760  as long as the boost converter circuit  760  is enabled and operated. 
       FIG. 2  is a second embodiment of the linear LED lamp according to the present disclosure.  FIG. 2  is almost the same as  FIG. 1 , except that the bidirectional circuit  703  in  FIG. 2  further comprises a first control circuit  724  configured to regulate the forward electric current to flow into the rechargeable battery  500 . The one or more electronic switches  720  comprise a first set of one or more electronic switches  725  and a second set of one or more electronic switches  726 . The forward electric current is allowed to flow into the rechargeable battery  500  via the second set of one or more electronic switches  726 . The first set of one or more electronic switches  725  are configured to receive a second set of one or more signals sent from the primary control circuit  702  and to allow the reverse electric current to flow out of the rechargeable battery  500 . The second set of one or more electronic switches  726  comprise at least one transistor circuit  727  configured to activate the boost converter circuit  760 . In other words, the bidirectional circuit  703  is configured to receive the second set of one or more signals from the primary control circuit  702  and to allow the reverse electric current to flow out of the rechargeable battery  500  and to apply the terminal voltage to the boost converter circuit  760  to supply with energy and power up the boost control circuit  763  to activate the boost converter circuit  760  via a port “D”. 
       FIG. 3  is a third embodiment of the linear LED lamp according to the present disclosure.  FIG. 3  is almost the same as  FIG. 1 , except that the major power source  704  in  FIG. 3  is configured to receive a power from a second full-wave rectifier  410 , taking advantages of two independent power sources from two different full-wave rectifiers such that the normally-operated portion  311  can be turned off at any time without affecting functionality of the emergency-operated portion  810 . In  FIG. 3 , the normally-operated portion  311  comprises at least two electrical conductors “L′” and “N”, a first full-wave rectifier  310 , and the fly-back converter circuit  303 . The at least two electrical conductors “L” and “N” are configured to couple to “L” and “N” via a power switch  360 . The first full-wave rectifier  310  is configured to convert the line voltage from the AC mains into a primary DC voltage. In other words, the at least two electrical conductors “L” and “N” are coupled to a switched power, in which the normally-operated portion  311  can be turned off when the linear LED lamp  110  is not in use any time 
     In  FIG. 3 , the linear LED lamp further comprises a first end  181  and a second end  182  opposite to the first end  181 . The first full-wave rectifier  310  and the second full-wave rectifier  410  are configured to independently receive the line voltage, with the first full-wave rectifier  310  from a switched line voltage and with the full-wave rectifier  410  from an un-switched line voltage. Either of the first end  181  and the second end  182  comprises at least two electrical conductors, wherein each of the at least two electrical conductors is respectively coupled to the first full-wave rectifier  310  and the second full-wave rectifier  410 . The second full-wave rectifier  410  is thus configured to power the major power source  704  at all times. The second full-wave rectifier  410  is coupled to the at least two electrical conductors “L” and “N” and configured to convert the line voltage into a main DC voltage. The rechargeable battery  500  comprises a high-potential electrode  501  and a low-potential electrode  502  with a terminal voltage across thereon. The major power source  704  is an isolated step-down converter. 
       FIG. 4  is a timing diagram of a self-diagnostic circuit according to the present disclosure. As mentioned in depicting  FIG. 1 , the self-diagnostic circuit  740  comprises the one or more timers  741 , and the test portion  742 , which, in one embodiment, may be implemented in hardware as an electronic circuit. Each of the one or more timers  741  respectively comprises multiple time delays comprising at least one initial time delay  834  with a duration of T 1  and a next time delay  835  with a duration of T 2  immediately followed the at least one initial time delay  834 . Upon an initiation of each of the one or more timers  741 , the at least one initial time delay  834  begins with an input voltage  738  applied. At the end of the at least one initial time delay  834 , an output  739  of the self-diagnostic circuit  740  is activated to reach the logic high level (i.e. “1” state) and remains activated so as to enable the boost converter circuit  760 , and the test portion  742  for the next time delay  835 . At the end of the next time delay  835 , the output  739  of the self-diagnostic circuit  740  is inactivated to drop to the logic low level (i.e. “0” state). The at least one initial time delay  834  and the next time delay  835  form a primary sequence with a duration of T 1 +T 2 . The primary sequence with the duration of T 1 +T 2  repeats ( 836  and  837 , for example) until the terminal voltage ( FIG. 1 ) is removed from the self-diagnostic circuit  740 . In  FIG. 4 , the input  738  shown comprises two states “0” and “1”, in which “0” means no voltage appeared at the input  738  of the self-diagnostic circuit  740  whereas “1” means the terminal voltage is applied. Similarly, the output  739  shown comprises two states “0” and “1”, in which “0” means no voltage appeared or being inactivated at the output  739  of the self-diagnostic circuit  740  whereas “1” means that the output  739  of the self-diagnostic circuit  740  provides an output high-level voltage or is activated. The duration T 2  over the next time delay  835  is configured (e.g., being sufficiently long) to allow the self-diagnostic circuit  740  to perform the rechargeable battery test. In other words, the self-diagnostic circuit  740  sends the output high-level voltage to enable the boost converter circuit  760  via the port “C” (in  FIG. 1  and  FIG. 3 ) or via the port “D” (in  FIG. 2 ) during the next time delay  835 . The respective at least one initial time delay  734  comprises a nominal duration of 30 days. The respective next time delay  835  comprises a nominal duration of 30 seconds. The primary sequence with the duration of T 1 +T 2  repeats ( 836  and  837 , for example) 11 times. At the twelfth time, the respective next time delay  835  comprises a nominal duration of 90 minutes. Afterwards, the primary sequence repeats until the terminal voltage ( FIG. 1 ) is removed from the self-diagnostic circuit  740 . 
       FIG. 5  is controllable increments of energy pulses and a regulated source of usable output power providing a first LED driving current according to the present disclosure. In  FIG. 5 , the boost converter circuit  760  cuts off a constant source of power from the rechargeable battery  500  into a plurality of controllable increments of energy pulses  931 , followed by a filter associated with the at least one capacitor  765  (in  FIGS. 1-3 ) to rebuild the plurality of controllable increments of energy pulses  931  back into a regulated output voltage  951 , which is a usable output power source providing the first LED driving current. In  FIG. 5 , each of the plurality of controllable increments of energy pulses  931  comprises an on-time duration  932  of 1.15 microseconds (μs). The at least one capacitor  765  filters the plurality of controllable increments of energy pulses  931  back into the regulated output voltage  951 , which is greater than the forward voltage across the one or more LED arrays  214  to operate thereon. 
     The self-diagnostic circuit  740  may comprise a microcontroller, a microchip, or a programmable logic controller. In this disclosure, the emergency-operated portion  810  is integrated into the linear LED lamp  110  with the self-diagnostic circuit  740  to auto-test charging and discharging current of a rechargeable battery  500  with test results displayed in a status indicator, supporting dual mode operations of the linear LED lamp  110  to work not only in a normal mode but also in an emergency mode. 
     Whereas preferred embodiments of the present disclosure have been shown and described, it will be realized that alterations, modifications, and improvements may be made thereto without departing from the scope of the following claims. Another kind of schemes with an emergency-operated portion with bidirectional circuits and multiple timers and multiple time delays adopted to operate a linear LED lamp using various kinds of combinations to accomplish the same or different objectives could be easily adapted for use from the present disclosure. Accordingly, the foregoing descriptions and attached drawings are by way of example only and are not intended to be limiting.