Abstract: A heat recovery apparatus and process for cracked gas are provided. The cracked gas comprises liquid feedstock cracked gas and gaseous feedstock cracked gas, and the apparatus comprises a heat recovery device for liquid feedstock cracked gas, a heat recovery device for gaseous feedstock cracked gas and a heavy component removal unit. The invention solves the problems in the art, i.e., incomplete heat recovery technology for cracked gas, insufficient control of viscosity of quench oil, high capital investment and large footprint of the equipment, as well as unstable operation and high energy consumption.

Abstract: The application discloses a dimming control circuit, a dimming control method, and a LED driver circuit. The dimming control circuit comprises a logic signal generation circuit and a feedback signal generation circuit. wherein the logic signal generation circuit is configured to compare the sampling signals with a first threshold signal and a second threshold signal respectively to obtain a first group of logic signals and a second group of logic signals. Wherein the feedback signal generation circuit is coupled to the logic signal generation circuit, which is configured to generate feedback signals to reduce energy output when each of the sampling signals is greater than the first threshold signal, and configured to generate feedback signals to increase the energy output when any one of the sampling signals is smaller than the second threshold signal.

Abstract: A dimming circuit for dimming a current flowing through a light emitting device, having: a multi-function pin, configured to receive a dimming signal; wherein when the dimming signal is an analog voltage signal, an amplitude of the current flowing through the light emitting device is regulated based on the dimming signal; when the dimming signal is a pulse signal and a frequency of the dimming signal is in a first frequency range, a duty cycle of the current flowing through the light emitting device is regulated based on the dimming signal; and when the dimming signal is the pulse signal and the frequency of the dimming signal is in a second frequency range, the amplitude of the current flowing through the light emitting device is regulated based on the dimming signal.

Abstract: A dimming circuit for dimming a current flowing through a light emitting device, having: a multi-function pin, configured to receive a dimming signal; wherein when the dimming signal is an analog voltage signal, an amplitude of the current flowing through the light emitting device is regulated based on the dimming signal; when the dimming signal is a pulse signal and a frequency of the dimming signal is in a first frequency range, a duty cycle of the current flowing through the light emitting device is regulated based on the dimming signal; and when the dimming signal is the pulse signal and the frequency of the dimming signal is in a second frequency range, the amplitude of the current flowing through the light emitting device is regulated based on the dimming signal.

Abstract: A control circuit of a power converter providing at least a first output voltage and a second output voltage, having: a first loop control circuit, configured to provide a first error amplifying signal based on the first output voltage and a first reference voltage; a second loop control circuit, configured to provide a second error amplifying signal based on the second output voltage and a second reference voltage; a saturation detecting circuit, configured to provide a saturation indicating signal based on the first error amplifying signal and a saturation reference signal; and a first current source circuit, configured to charge an output terminal of the second error amplifier based on the saturation indicating signal.

Abstract: A control circuit of a power converter providing at least a first output voltage and a second output voltage, having: a first loop control circuit, configured to provide a first error amplifying signal based on the first output voltage and a first reference voltage; a second loop control circuit, configured to provide a second error amplifying signal based on the second output voltage and a second reference voltage; a saturation detecting circuit, configured to provide a saturation indicating signal based on the first error amplifying signal and a saturation reference signal; and a first current source circuit, configured to charge an output terminal of the second error amplifier based on the saturation indicating signal.

Abstract: A LED driving system has an energy storage component receiving an input voltage, a power switch coupled between the energy storage component and a reference ground, a first output switch coupled between the energy storage component and a first output terminal, a second output switch coupled between the energy storage component and a second output terminal, and a control circuit, wherein the first output terminal produces a first output voltage to supply power for a first LED array, the second output terminal produces a second output voltage to supply power for a second LED array, the control circuit controls a duty cycle of the first output switch according to voltages at cathode terminals of multiple LED strings in the LED array and controls a duty cycle of the second output switch according to voltages at cathode terminals of multiple LED strings in the second LED array.

Abstract: A voltage converter provides a positive voltage and a negative voltage with a single inductor. The voltage converter has a first switch, a second switch, a third switch and a fourth switch switched periodically, wherein each switching period comprise a first time period, a second time period and a third time period, and wherein: during the first time period, the first switch and the fourth switch are turned on, whereas the second switch and the third switch are turned off; during the second time period, the first switch and the third switch are turned on, whereas the second switch and the fourth switch are turned off; and during the third time period, the second switch and the fourth switch are turned on, whereas the first switch and the third switch are turned off.

Abstract: A LED driving system has an energy storage component receiving an input voltage, a power switch coupled between the energy storage component and a reference ground, a first output switch coupled between the energy storage component and a first output terminal, a second output switch coupled between the energy storage component and a second output terminal, and a control circuit, wherein the first output terminal produces a first output voltage to supply power for a first LED array, the second output terminal produces a second output voltage to supply power for a second LED array, the control circuit controls a duty cycle of the first output switch according to voltages at cathode terminals of multiple LED strings in the LED array and controls a duty cycle of the second output switch according to voltages at cathode terminals of multiple LED strings in the second LED array.

Abstract: A voltage converter provides a positive voltage and a negative voltage with a single inductor. The voltage converter has a first switch, a second switch, a third switch and a fourth switch switched periodically, wherein each switching period comprise a first time period, a second time period and a third time period, and wherein: during the first time period, the first switch and the fourth switch are turned on, whereas the second switch and the third switch are turned off; during the second time period, the first switch and the third switch are turned on, whereas the second switch and the fourth switch are turned off; and during the third time period, the second switch and the fourth switch are turned on, whereas the first switch and the third switch are turned off.

Abstract: A method of capacitive mode detection is used in a resonant converter. The resonant converter has a square wave generator having a first switch and a second switch, a resonant network, an isolated transformer having a primary winding and a second winding, and a rectifier network providing an output DC voltage for a load. The method of capacitive mode detection includes: detecting a voltage of the secondary winding and generating a voltage detection signal; detecting an output DC voltage of the rectifier network and generating a voltage detecting threshold; comparing the voltage detection signal with the voltage detection threshold when either of the first and the second switches is turned OFF; generating a flag signal indicating whether the resonant converter enters into a capacitive mode based on the comparison result.

Abstract: A light-emitting element driver system has a power conversion circuit, a second switch and a control circuit, the power conversion circuit has a primary circuit, a transformer, a first rectified circuit and a second rectified circuit, the second rectified circuit provides a first signal, the second switch has a first terminal coupled to an output terminal of the first rectified circuit and a second terminal to provide a second signal, when a dimming signal is in a first state, the control circuit provides a first control signal to control the power conversion circuit based on the first signal, and meanwhile provides a second control signal to control the second switch based on the second signal.

Abstract: A method of capacitive mode detection is used in a resonant converter. The resonant converter has a square wave generator having a first switch and a second switch, a resonant network, an isolated transformer having a primary winding and a second winding, and a rectifier network providing an output DC voltage for a load. The method of capacitive mode detection includes: detecting a voltage of the secondary winding and generating a voltage detection signal; detecting an output DC voltage of the rectifier network and generating a voltage detecting threshold; comparing the voltage detection signal with the voltage detection threshold when either of the first and the second switches is turned OFF; generating a flag signal indicating whether the resonant converter enters into a capacitive mode based on the comparison result.

Abstract: A method having a negative output voltage at a negative output terminal of a charge pump tracking a positive output voltage at a positive output terminal of the charge pump. The charge pump comprises a plurality of switches and each of the plurality of switches has a serially coupled resistance. The method comprises selecting the serially coupled resistance for at least one of the plurality of switches to be different to each of the other respective serially coupled resistances associated to the other switches.

Abstract: The embodiments of the present circuit and method disclose a light-emitting diode (LED) driver system. The LED driver system may comprise an isolated converter and a DC/DC converter. The isolated converter may be coupled to a first input signal, and may provide a LED current and a bus voltage. The isolated converter may be configured to regulate the LED current and the bus voltage separately in accordance with a dimming signal. The DC/DC converter may comprise an input coupled to the bus voltage.

Abstract: A light-emitting element driver system has a power conversion circuit, a second switch and a control circuit, the power conversion circuit has a primary circuit, a transformer, a first rectified circuit and a second rectified circuit, the second rectified circuit provides a first signal, the second switch has a first terminal coupled to an output terminal of the first rectified circuit and a second terminal to provide a second signal, when a dimming signal is in a first state, the control circuit provides a first control signal to control the power conversion circuit based on the first signal, and meanwhile provides a second control signal to control the second switch based on the second signal.

Abstract: Light emitting diode (LED) dimming and driver systems and associated methods of control are disclosed herein. In one embodiment, a system comprises a PFC stage and an LED driver stage. The LED driver stage comprises an isolated converter and a controller responsive to a dimming signal to dim LED strings for backlight. The controller also regulates an output current of the isolated converter.

Abstract: LED driver systems and associated methods of control are disclosed herein. In one embodiment, the LED driver system comprises a converter and a controller. The controller is responsive to the LED current feedback signal and a dimming signal, and operable to generate a continuous gate drive signal to control the primary side switch of the converter. Thus, the controller regulates the output current of the converter.

Abstract: A method having a negative output voltage at a negative output terminal of a charge pump tracking a positive output voltage at a positive output terminal of the charge pump. The charge pump comprises a plurality of switches and each of the plurality of switches has a serially coupled resistance. The method comprises selecting the serially coupled resistance for at least one of the plurality of switches to be different to each of the other respective serially coupled resistances associated to the other switches.

Abstract: The embodiments of the present circuit and method disclose a light-emitting diode (LED) driver system. The LED driver system may comprise an isolated converter and a DC/DC converter. The isolated converter may be coupled to a first input signal, and may provide a LED current and a bus voltage. The isolated converter may be configured to regulate the LED current and the bus voltage separately in accordance with a dimming signal. The DC/DC converter may comprise an input coupled to the bus voltage.