Asian Power Devices Inc.

Yu-Chi Lai

Guang-Ming Lei

Ji-Shun Liao

Cheng-Chang Yang

Sheng-Fa Chi

A light emitting diode (LED) circuit having even current has multiple LED strings, a current equalizing integrated circuit (IC) and a voltage compensation module. The LED strings are connected to an external power source, and each LED string has a power terminal and a driving terminal. The current equalizing IC has multiple driving pins connected respectively to the driving terminals of the LED strings. The voltage compensation module is connected between the LED strings and the external power source and has a threshold voltage value and multiple input terminals. The input terminals are connected respectively to the driving pins of the current equalizing IC to allow the voltage compensation module rise and send the voltage obtained from the external power source to the LED strings when the voltage compensation module determines any voltage on the driving pins of the current equalizing IC is lower than the threshold voltage value.

Light emitting diode circuit having even current

A charger with output voltage compensation includes an AC/DC circuit, an output interface, a charge controller, and a compensator. The AC/DC circuit converts an AC source into a DC source. The voltage of the DC source is elevated by a transformer and used to charge a battery via the output interface. The charge controller can further increase the voltage of the output interface in order to accelerate battery charging. The compensator compensates the voltage wasted by the circuit. Therefore, the invention can overcome energy waste caused by the internal resistance in the circuit, achieving satisfactory charging effects.

Charger with output voltage compensation

A two-step charger includes an AC/DC power supply, a transformer, a compensator, a controller, a comparator and an isolating controller. The comparator detects whether a battery is connected to the transformer. If so, a command voltage of the charger is set at a high level. Since the battery voltage is lower than the command voltage, the controller orders the compensator to send out a compensating current. The current entering the primary side of the transformer is increased to promote the output current from the secondary side of the transformer. Once the comparator detects that the battery reaches as high as the charger, the command voltage is adjusted to a low level. The controller orders the compensator to stop outputting the compensating current. Therefore, a larger current can speed up battery charging. Once the battery is fully charged, the charging voltage is lowered to avoid high temperature.

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Taoyuan, Taiwan

Yu-Chi Lai