Linear solid-state lighting with ballast free of electric shock hazard
View Patent ↗A linear light-emitting diode (LED)-based solid-state lamp using an AC current control scheme and shock protection switches operates normally with an electronic ballast. Due to the use of shock protection switches in the two lamp bases at two opposite ends, the ballast-compatible LED lamp fully protects a person from possible electric shock during initial installation, maintenance, and re-lamping no matter what the rated power and the brand of the LLT lamp are and no matter whether the electronic ballast is existing used ones that may be incompatible with the lamp or faulty, leading to an unacceptable leakage current.
1. A linear light-emitting diode (LED) tube lamp, comprising:
a housing comprising two ends;
a light-emitting diode printed circuit board (LED PCB), the LED PCB comprising LED arrays fixed thereon;
two lamp bases respectively connected to the two ends of the housing, each lamp base comprising a shock protection switch and a bi-pin with the bi-pin comprising two pins protruding outwards; and
an LED driver comprising interface ports receiving power from an electronic ballast through the bi-pins and the shock protection switches in the two lamp bases and powering the LED arrays;
wherein the shock protection switch of each of the lamp bases comprises:
two sets of electrical contacts, each set comprising at least two electrical contacts with one electrical contact electrically connected to one of the two pins of the bi-pin and another electrical contact electrically connected to one of the interface ports of the LED driver; and
at least one switch actuation mechanism comprising a front portion protruding outwards;
wherein, in each lamp base, when the shock protection switch is off, the bi-pin is not electrically connected to the LED driver, and
wherein, in each lamp base, when the front portion of the switch actuation mechanism is pressed in or twisted on by installing the bi-pin of the lamp base in a lamp socket, the shock protection switch is actuated, and the electrical contacts of each of the two sets of electrical contacts are electrically connected to electrically connect the bi-pin to the LED driver.
2. The linear LED tube lamp of claim 1 , wherein the LED driver comprises:
an interface module comprising at least one frequency sensitive device and two termination devices, each termination device connecting between the two pins of each of the bi-pins through each of the shock protection switches;
a voltage sensing and control module provided to receive power from the interface module and to guide the electric current flow; and
an LED driving module connected to the LED arrays.
3. The linear LED tube lamp of claim 2 , wherein the at least one frequency sensitive device comprises at least one capacitor connecting between one of the termination devices and the voltage sensing and control module.
4. The linear LED tube lamp of claim 2 , wherein the voltage sensing and control module comprises at least one full-wave rectifier comprising at least four diodes.
5. The linear LED tube lamp of claim 2 , wherein the interface module and the voltage sensing and control module are of non-hardware type, implemented by an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a microcontroller.
6. The linear LED tube lamp of claim 1 , wherein each of the shock protection switches is of a contact type.
7. The linear LED tube lamp of claim 6 , wherein each of the shock protection switches is a snap switch, a push-button switch, a micro switch, a twist-on switch, or a rotary switch.
8. The linear LED tube lamp of claim 1 , wherein each of the shock protection switches is of a non-contact type.
9. The linear LED tube lamp of claim 8 , wherein each of the shock protection switches is electro-mechanical, electromagnetic, optical, electro-optic, fiber-optic, infrared, or wireless based.
10. The linear LED tube lamp of claim 8 , wherein each of the shock protection switches is of a sensing type, comprising a proximity control with a sensing range up to 8 mm.