Abstract: A power converting circuit having the function of circuit detecting is provided. The power converting circuit has a transistor, a controller and a detecting circuit. The transistor receives an input voltage. The controller is coupled to a control end of the transistor to control the conducting state of the transistor so as to stabilize the output of the power converting circuit. The detecting circuit detects at least one of the control end and the low voltage end of the transistor, and generates a state signal when the detected voltage of any one of the control end and the low voltage end does not fall within a corresponding predetermined voltage range. The state signal is utilized for stopping a power circuit which provides the input voltage providing the input voltage. In addition, a light emitting diode driving circuit having the function of circuit detecting is also provided.

Abstract: An LED driving circuit is provided for driving an LED module, comprising a transistor switch and a feedback controller. The transistor switch has a control terminal, a first terminal, and a second terminal. The first terminal is coupled to the LED module and the control terminal receives a control signal for controlling a current passing through the transistor switch. The feedback controller receives a reference voltage and a current detecting signal indicative of the magnitude of the current and generates the control signal accordingly. The feedback controller is connected to a driving power source with level higher than the level of the first terminal of the transistor switch. Hence, the maximum level of an adjustable range of the control signal is higher than the first terminal of the transistor switch.

Abstract: A direct current to alternating current (DC/AC) inverter is for driving a fluorescent lamp through quasi sine wave generation. The DC/AC inverter includes a frequency generator for generating a reference signal and a modulation signal, a pulse width modulator coupled to the frequency generator for providing a pulse width modulation signal according to said modulation signal, a driver circuit coupled to the pulse width modulator for generating at least one driving signal according to the pulse width modulation signal and the reference signal, a half bridge power switch unit coupled to the driver circuit, and a resonant tank coupled to the fluorescent lamp for outputting a quasi sine wave to drive the fluorescent lamp.

Abstract: A feedback circuit is utilized in a DC/AC inverter having a first power switch and a second power switch for driving a fluorescent lamp. The feedback circuit includes a protection circuit for disabling the first power switch and the second power switch when no fluorescent lamp is electrically connected, a first capacitor having a first terminal electrically connected to an output of the DC/AC inverter, a second capacitor having a first terminal electrically connected to a ground, and a second terminal electrically connected to a second terminal of the first capacitor, a diode having an anode electrically connected to the second terminals of the first and second capacitors, and a cathode electrically connected to the protection circuit, and a first resistor having a first terminal electrically connected to the cathode of the diode, and a second terminal electrically connected to the ground.

Abstract: An LED current control circuit including a current adjusting unit, a detecting unit, and a current control unit is provided. The current adjusting unit has a current control end coupled to an LED string for determining an amount of current flowing through the LED string according to a current control signal. The detecting unit detects the current control end and determines whether to generate a protecting signal according to a protecting voltage value. The current control unit generates the current control signal to control the amount of current flowing through the LED string of and determines whether to stop the current flowing through the LED string according to the protecting signal.

Abstract: A battery voltage balance apparatus including a balance determining unit and a converting unit is provided. The balance determining unit is coupled to a plurality of battery units and determines whether to perform a battery voltage balance process according to battery voltages of each battery units. The converting unit has an energy storage circuit and is coupled to the battery units. In the battery voltage balance process, the converting unit stores energy in the energy storage circuit and selectively charging at least one of the battery units by the energy storage circuit, so that the voltage differences between any two of the battery units are reduced to be lower than a predetermined value or a predetermined percentage.

Abstract: A power converting circuit including a converting circuit and a controller is provided. In an embodiemnt of the invention, the inductance of the converting circuit and the operation frequency of the controller can be adjusted according to the power required by the load and/or the size of the inductor current to effectively reduce the switching times and the switching loss of the switch in the converting circuit when the load is light. Accordingly, no matter the load is light or heavy, the efficiency of the power converting circuit can be maintained at a higher standard.

Abstract: A load driving circuit and a multi-load feedback circuit are disclosed. The load driving circuit and the multi-load feedback circuit are adapted to drive an LED module comprising a current balancing circuit for balancing the current flowing through LEDs. The load driving circuit and the multi-load feedback circuit modulate the electric power transmitted by the LED driving apparatus to an LED module according to voltage level(s) of one or more current balancing terminals having insufficient voltage in the current balancing circuit, so the voltage levels of the current balancing terminals are higher than or equal to a predetermined voltage level, further increasing the efficiency thereof.

Abstract: A load driving circuit and a multi-load feedback circuit is disclosed. The load driving circuit and the multi-load feedback circuit are adapted to drive a LED module that has a current balancing circuit for balancing the currents flowing through LEDs. The load driving circuit and the multi-load feedback circuit modules the electric power transmitted by the LED driving apparatus to a LED module according to voltage level(s) of current balancing terminals having insufficient voltage in the current balancing circuit, and so the voltage levels of the current balancing terminals are higher than or equal to a preset voltage level, further increasing the efficiency thereof.

Abstract: A multi-lamps LCD panel back-light control circuit is provided, and which includes a control unit, a full bridge switch, a resonance network circuit, a voltage transformer, and a feedback network. The control unit operates in coordinating with the full bridge switch, the resonance network circuit, the voltage transformer and the feedback network so as to use a constant operating frequency and a PWM feedback to control a current of CCFLs. The back-light control circuit is characterized in that different integrated-circuits (ICs) are respectively formed from the control unit including a PWM controller, a triangular wave/clock generator, a ½ frequency divider, and a logic circuit. The different ICs have either a plurality of respective frequency synchronous signal control terminals or a plurality of phase synchronous signal control terminals that are connected to one another so that the different ICs operate respectively either with a same operating frequency or a same phase.

Abstract: A power conversion driving circuit is provided. The power conversion drive circuit includes a converting circuit, a control circuit and a load circuit. The converting circuit is coupled to an input voltage. The control circuit is coupled to the converting circuit for controlling the converting circuit to convert the input voltage to an output voltage. The load circuit includes a load detecting unit and a load. The load is coupled to the output voltage, and the load detecting unit is coupled to a detecting voltage source. The load detecting unit generates a load detecting signal to re-start the control circuit when the load circuit is inserted into the power conversion driving circuit.

Abstract: A MOSFET current limiting circuit, a linear voltage regulator, and a voltage converting circuit are provided. A current limiting value of the MOSFET is adjusted with the temperature or the voltage drop across the drain and the source of the MOSFET. Accordingly, it is ensured that the MOSFET operates in the safe operating area in any situation. Therefore, the MOSFET is prevented from being burnt out, and the reliability thereof is also increased.

Abstract: A controller which receives electric power required for operating through a driving voltage terminal and controls a converting circuit to convert an input voltage into an output voltage is provided. The controller is latched to stop providing a part or all of functions until the input voltage is removed. Therefore, the issues of the converting circuit in related arts in shortened life-span and safety of users due to can be avoided in the present invention.

Abstract: A battery charging controlling apparatus for balancing voltages of the charged batteries is provided. The battery charging controlling includes a battery reference voltage generating unit, a voltage balancing unit, and a balance judging unit. The battery charging controlling apparatus determines whether a battery voltage difference between any two adjacent battery units of a battery module is too large or not by using a reference voltage provided from the battery reference voltage generating unit. The battery charging controlling apparatus further detects the voltage of the battery module and a charging current thereto to determine a suitable time for balancing the charged batteries. Then, the voltage balancing unit controlled by the balance judging unit allows the charging current of the lower-voltage battery unit greater than the charging current of the higher-voltage battery, unit so as to lower the battery voltage difference of the battery units.

Abstract: The present invention uses a discharge path to release the power stored in an output capacitor of a converting circuit when the time interval between two adjacent switching thereof is too long and may generate noises whose frequencies can be sensed by human ears. Hence, the present invention can keep the operating frequency of the converting circuit higher than a predetermined frequency and reduce the audio noise of the converting circuit.

Abstract: A DC/AC inverter provided for transforming a DC voltage source into an AC power source, wherein the AC signal is used for driving a fluorescent lamp. The inverter comprises a half-bridge switch circuitry electrically connected to the DC voltage source, for outputting an AC signal, a resonant tank electrically connected between the half-bridge switch circuitry and the fluorescent lamp, for stepping up and filtering the AC signal into a high-voltage AC power source which is supplied to a load, and a controller feeding back an output of the fluorescent lamp, providing a pulse width modulation signal for turning on and off the half-bridge switch circuitry, such that the fluorescent lamp can operate consistently and provide a consistent brightness.

Abstract: The present invention discloses a battery charging controller for balancing the charged batteries. The battery charging controller comprises a battery reference voltage generator, a voltage balancing module and a balance judging circuit. The battery charging controller determines which one has the lower voltage between battery units of a battery module according to reference voltages generated by the battery reference voltage generator. The voltage balancing module controlled by the balance judging circuit allows the charging current of the lower-voltage battery larger than the charging current of the higher-voltage battery in such that the final voltages of the battery units are substantially equaled when they are completely saturated.

Abstract: The present invention provides an LED driving circuit with temperature compensation, comprising a power transforming circuit, an LED module and a controller. The transforming circuit receives an electrical power from an input power source and transforms it into an output voltage according to a control signal. The LED module is coupled to the transforming circuit. The controller generates the control signal according to an operation temperature and a voltage feedback signal indicative of the output voltage, and makes the output voltage decrease with increasing operation temperature. Therefore, the LED driving circuit of the present invention has an effect of temperature compensation that compensates the influence of the decreased driving voltage of the LED module due to temperature.

Abstract: A feedback circuit is utilized in a DC/AC inverter having a first power switch and a second power switch for driving a fluorescent lamp. The feedback circuit includes a protection circuit for disabling the first power switch and the second power switch when no fluorescent lamp is electrically connected, a first capacitor having a first terminal electrically connected to an output of the DC/AC inverter, a second capacitor having a first terminal electrically connected to a ground, and a second terminal electrically connected to a second terminal of the first capacitor, a diode having an anode electrically connected to the second terminals of the first and second capacitors, and a cathode electrically connected to the protection circuit, and a first resistor having a first terminal electrically connected to the cathode of the diode, and a second terminal electrically connected to the ground.

Abstract: A multi-lamps LCD back-light control circuit comprises a control unit, an full bridge switch, a resonance network circuit, a voltage transformer, a lamp, and a feedback network. A constant operating frequency and a pulse width modulation (PWM) feedback are used to control the CCFL current. The back-light control circuit is such that a power switch of the full bridge switch outputs a duty cycle that is controlled and changed via a PWM controller of the control unit, while a ground switch of the full bridge switch outputs a constant duty cycle controllable above 50%.