Abstract: A power line resistance sensing device adapted to a lamp system with an LED module connected to a power supply between a supply line and a ground line. The power line resistance sensing device includes a control unit including a first pin connected to an LED switch to turn on or turn off the LED module; a second pin connected to a testing switch to fire a testing current from a testing current source into the lamp system before a full conduction of the lamp system; and a third pin used to receive a voltage drop induced by the testing current fired in the lamp system. The control unit is configured to compare the voltage drop with a predetermined safety voltage drop, thereby controlling the LED switch.

Abstract: A voltage regulation circuit for LED tube coupled to an energy input terminal being an AC source, a CCG or a ECG, comprising: a controlling part, including: a first impedance unit coupled to the energy input terminal; a second impedance unit coupled to the first impedance unit; and a third impedance unit coupled to the second impedance unit; and a controlled part including at least an LED unit and coupled to the controlling part; wherein a first terminal of the first impedance unit is coupled to a first terminal of the second impedance unit, a second terminal of the second impedance unit is coupled to a first terminal of the third impedance unit through a node, and the node is coupled to the controlled part.

Abstract: An LED device with energy compensation includes a first LED driving circuit, a second LED driving circuit, and a capacitor. The first LED driving circuit includes a first LED driver and a plurality of first LED groups controlled by the first LED driver. The second LED driving circuit including a second LED driver and a plurality of second LED groups controlled by the second LED driver. The second LED driving circuit is connected in parallel with the first LED driving circuit. The capacitor has a first terminal coupled to the second LED driving circuit and a second terminal coupled to one of the first LED driving circuit and the second LED driver. A power source is coupled to the first LED driving circuit, the second LED driving circuit, and the first terminal of the capacitor for applying an AC power to the first terminal of the capacitor.

Abstract: A high-safety LED tube, comprising: a first side having a first electrode and a second electrode; a second side having a third electrode and a fourth electrode; a first impedance module coupled to the first side; a second impedance module coupled to the second side; a first energy sensor having a first terminal coupled to the first impedance module; a second energy sensor having a first terminal coupled to the second impedance module; an LED unit coupled to the first impedance module and the second impedance module; a switch coupled to the LED unit; and a state control module coupled to the switch; wherein, when the first energy sensor or the second energy sensor detects an energy flowing between the first electrode and the second electrode or between the third electrode and the fourth electrode, the state control module turns on the switch.

Abstract: A filament simulation circuit for LED tube, comprising: two filament simulation parts respectively disposed on two terminals of a tube to receive a current from an electronic ballast, each filament simulation part including two sub-filament simulation parts, each sub-filament simulation part including a first resistor, a capacitor and a inductor, wherein each sub-filament simulation part is divided into: a first part; and a second part connected in series to the first part, the second part having a parallel connection structure; wherein an impedance of the sub-filament simulation part in a pre-heated stage is greater than that in an operating stage.

Abstract: An LED control circuit, comprising: a current source including a positive terminal and a negative terminal for providing a current; an LED, which is disposed on a first current path, including an anode and a cathode where the anode is connected to the positive terminal of the current source; an LED monitor including an input terminal and an output terminal where the input terminal is connected to the anode or the cathode of the LED; and a second current path connected in parallel to the first current path; wherein, when the LED monitor detects that the first current meets a target value, if the source current provided by the power source is greater than the target value, a second current divided from the source current flows through the second current path.

Abstract: An LED control system, comprising: a power source; an LED connected to the power source; a first switch connected in series with the LED; a second switch connected in parallel with the LED; a first regulation module including the first path to regulate a power applied to the LED; a second regulation module sharing the first path with the first regulation module to regulate the power applied to the LED; a check module to detect an energy value on a node of the LED control system; and a control module connected to the power source check module, the first regulation module, and the second regulation module; wherein when the check module detects that the energy value on the node is greater than a predefined value, the control module disables the regulation module in operation and enables the other regulation module.