Top Victory Investments Limited

Chen-Chiang Lee

Li-Wei Lin

Chi-Hsin Lee

Yuan-Po Huang

Wen-Ming Lin

Chun-Chi Liao

A switched-mode power supply (SMPS), capable of catching radiated electromagnetic interference (EMI) and using its energy, includes a specific component, an antenna, a rectifier, and an energy storage capacitor or a rechargeable battery. The specific component generates radiated EMI. The antenna is disposed on or embedded in the specific component, and the frequency range of the antenna corresponds to the frequency band of the radiated EMI generated by the specific component. The rectifier is electrically connected with a terminal of the antenna. The energy storage capacitor or the rechargeable battery is electrically connected with the rectifier. The SMPS may simplify the design of circuits for suppressing radiated EMI to reduce cost, and to achieve the purpose of power saving by recycling and reuse of dissipated energy.

Switched-mode power supply capable of catching radiated electromagnetic interference and using its energy

A serial-type LED device includes p light source units and a dimming circuit. Each light source unit includes first and second terminals, m light strings and m current balance units. Each light string includes LEDs coupled in series to have a first terminal coupled to the first terminal of a corresponding light source unit and a second terminal coupled to the second terminal of the corresponding light source unit through a corresponding current balance unit. The first terminal of the first light source unit is coupled to a second DC voltage, and the second terminal of the i-th light source unit is coupled to the first terminal of the (i+1)-th light source unit, where m and p are integers greater than or equal to 2 and i is any integer from 1 to (p&#x2212;1). The dimming circuit coupled to the second terminal of the p-th light source unit controls the second DC voltage according to a current outputted from the p-th light source unit.

Serial-type light-emitting diode (LED) device

A light-emitting diode (LED) driving circuit for driving a plurality of first lightbars and a plurality of second lightbars is provided. The LED driving circuit includes a first current mirror, a second current mirror and a control circuit. The first current mirror, if enabled, balances currents of the first lightbars. The second current mirror, if enabled, balances currents of the second lightbars. During a first period, the control circuit disables the second current mirror and adjusts the duration of enabling the first current mirror according to a dimming signal. During a second period, the control circuit disables the first current mirror and adjusts the duration of enabling the second current mirror according to the dimming signal. Therefore, only the first lightbars or the second lightbars are driven in each period.

Light-emitting diode (LED) driving circuit

A serial-type LED device includes p light source units and a dimming circuit. Each light source unit includes first and second terminals, m light strings and m current balance units. Each light string includes LEDs coupled in series to have a first terminal coupled to the first terminal of a corresponding light source unit and a second terminal coupled to the second terminal of the corresponding light source unit through a corresponding current balance unit. The first terminal of the first light source unit is coupled to a second DC voltage, and the second terminal of the i-th light source unit is coupled to the first terminal of the (i+1)-th light source unit, where m and p are integers greater than or equal to 2, and i is any integer from 1 to (p&#x2212;1). The dimming circuit coupled to the second terminal of the p-th light source unit controls the second DC voltage according to a current outputted from the p-th light source unit.

A light-emitting diode (LED) current balance circuit includes a reference current generator, a current mirror and a voltage compensation circuit. The reference current generator provides a reference current robust against disturbance in a supply voltage applied to the reference current generator. The current mirror generates, according to the reference current, sink currents to bias lightbars and employs a structure to reduce the influence of unmatched transistors on the sink currents to stabilize and clamp currents through the lightbar. The voltage compensation circuit detects the voltages across the lightbars to compensate the lightbars having various forward voltages to ensure the turn-on of all lightbars and to effectively balance the currents through the lightbars. Therefore, a simpler circuit architecture is employed which does not need a specific-purpose LED controller to be cheaper and more competitive.

Light-emitting diode (LED) current balance circuit

A light-emitting diode (LED) driving circuit for driving a plurality of first lightbars and a plurality of second lightbars includes a first current mirror, a second current mirror and a control circuit. The first current mirror, if enabled, balances current among the first lightbars. The second current mirror, if enabled, balances current among the second lightbars. During a first period, the control circuit disables the second current mirror and adjusts the duration of enabling the first current mirror according to a dimming signal. During a second period, the control circuit disables the first current mirror and adjusts the duration of enabling the second current mirror according to the dimming signal. Therefore, only first or second lightbars are driven in each period.

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Taipei, Taiwan

Chen-Chiang Lee