Abstract: System and method for regulating a power converter. The system includes a first signal generator configured to receive a first sensed signal and generate an output signal associated with demagnetization. The first sensed signal is related to a first winding coupled to a secondary winding for a power converter, and the secondary winding is associated with at least an output current for the power converter. Additionally, the system includes a ramping signal generator configured to receive the output signal and generate a ramping signal, and a first comparator configured to receive the ramping signal and a first threshold signal and generate a first comparison signal based on at least information associated with the ramping signal and the first threshold signal. Moreover, the system includes a second comparator configured to receive a second sensed signal and a second threshold signal and generate a second comparison signal.

Abstract: System and method for regulating a power conversion system. For example, a system controller for regulating a power conversion system includes an amplifier, a variable-resistance component, a capacitor, and a modulation and drive component. The amplifier is configured to receive a reference signal and a feedback signal associated with an output signal of the power conversion system, the amplifier including an amplifier terminal. The variable-resistance component is associated with a first variable resistance value, the variable-resistance component including a first component terminal and a second component terminal, the first component terminal being coupled with the amplifier terminal. The capacitor includes a first capacitor terminal and a second capacitor terminal, the first capacitor terminal being coupled with the second component terminal. The modulation and drive component includes a first terminal and a second terminal, the first terminal being coupled with the amplifier terminal.

Abstract: System and method for regulating a power conversion system. An example system controller includes: a first controller terminal and a second controller terminal. The system controller is configured to: receive an input signal at the first controller terminal and generate a first drive signal at the second controller terminal based on at least information associated with the input signal to turn on or off a transistor to affect a current associated with a secondary winding of the power conversion system. The system controller is further configured to: in response to the input signal changing from a first value larger than a first threshold to a second value smaller than the first threshold, change the first drive signal from a first logic level to a second logic level to turn on the transistor.

Abstract: System and method for regulating a power conversion system. An example system controller includes: a first controller terminal and a second controller terminal. The system controller is configured to: receive an input signal at the first controller terminal and generate a first drive signal at the second controller terminal based on at least information associated with the input signal to turn on or off a transistor to affect a current associated with a secondary winding of the power conversion system. The system controller is further configured to: in response to the input signal changing from a first value larger than a first threshold to a second value smaller than the first threshold, change the first drive signal from a first logic level to a second logic level to turn on the transistor.

Abstract: System controller and method for regulating a power converter. For example, the system controller includes a first controller terminal and a second controller terminal. The system controller is configured to: receive, at the first controller terminal, an input signal; generate a drive signal based at least in part on the input signal, the drive signal being associated with an on-time period and an off-time period, the on-time period including a first beginning and a first end; and output, at the second controller terminal, the drive signal to a switch to close the switch during the on-time period and open the switch during the off-time period to affect a current associated with a secondary winding of the power converter. The system controller is further configured to detect a demagnetization period associated with the secondary winding based at least in part on the input signal.

Abstract: System controller and method for regulating a power converter. For example, the system controller includes a first controller terminal and a second controller terminal. The system controller is configured to: receive, at the first controller terminal, an input signal; generate a drive signal based at least in part on the input signal, the drive signal being associated with an on-time period and an off-time period, the on-time period including a first beginning and a first end; and output, at the second controller terminal, the drive signal to a switch to close the switch during the on-time period and open the switch during the off-time period to affect a current associated with a secondary winding of the power converter. The system controller is further configured to detect a demagnetization period associated with the secondary winding based at least in part on the input signal.

Abstract: System controller and method for regulating a power converter. For example, the system controller includes a first controller terminal and a second controller terminal. The system controller is configured to: receive, at the first controller terminal, an input signal; generate a drive signal based at least in part on the input signal, the drive signal being associated with an on-time period and an off-time period, the on-time period including a first beginning and a first end; and output, at the second controller terminal, the drive signal to a switch to close the switch during the on-time period and open the switch during the off-time period to affect a current associated with a secondary winding of the power converter. The system controller is further configured to detect a demagnetization period associated with the secondary winding based at least in part on the input signal.

Abstract: System and method for regulating a power conversion system. For example, a system controller for regulating a power conversion system includes an amplifier, a variable-resistance component, a capacitor, and a modulation and drive component. The amplifier is configured to receive a reference signal and a feedback signal associated with an output signal of the power conversion system, the amplifier including an amplifier terminal. The variable-resistance component is associated with a first variable resistance value, the variable-resistance component including a first component terminal and a second component terminal, the first component terminal being coupled with the amplifier terminal. The capacitor includes a first capacitor terminal and a second capacitor terminal, the first capacitor terminal being coupled with the second component terminal. The modulation and drive component includes a first terminal and a second terminal, the first terminal being coupled with the amplifier terminal.

Abstract: System controller and method for regulating a power converter. For example, the system controller includes a first controller terminal and a second controller terminal. The system controller is configured to receive an input signal at the first controller terminal and generate a drive signal at the second controller terminal based at least in part on the input signal to turn on or off a transistor in order to affect a current associated with a secondary winding of the power converter. Additionally, the system controller is further configured to determine whether the input signal remains larger than a first threshold for a first time period that is equal to or longer than a first predetermined duration.

Abstract: System and method for protecting a power converter. The system includes a first comparator configured to receive a first threshold signal and a first signal and to generate a first comparison signal. The first signal is associated with an input current for a power converter. Additionally, the system includes a second comparator configured to receive a second threshold signal and the first signal and to generate a second comparison signal. The second threshold signal is different from the first threshold signal in magnitude. Moreover, the system includes a first detection component configured to receive at least the second comparison signal, detect the second comparison signal only if one or more predetermined conditions are satisfied, and generate a first detection signal based on at least information associated with the detected second comparison signal.

Abstract: System and method for regulating a power conversion system. For example, a system controller for regulating a power conversion system includes an amplifier, a variable-resistance component, a capacitor, and a modulation and drive component. The amplifier is configured to receive a reference signal and a feedback signal associated with an output signal of the power conversion system, the amplifier including an amplifier terminal. The variable-resistance component is associated with a first variable resistance value, the variable-resistance component including a first component terminal and a second component terminal, the first component terminal being coupled with the amplifier terminal. The capacitor includes a first capacitor terminal and a second capacitor terminal, the first capacitor terminal being coupled with the second component terminal. The modulation and drive component includes a first terminal and a second terminal, the first terminal being coupled with the amplifier terminal.

Abstract: System controller and method for regulating a power converter. For example, the system controller includes a first controller terminal and a second controller terminal. The system controller is configured to receive, at the first controller terminal, an input signal, generate a drive signal based at least in part on the input signal, and output, at the second controller terminal, the drive signal to a switch to affect a current associated with a secondary winding of the power converter. The system controller is further configured to detect a first duration of a demagnetization period associated with the secondary winding based at least in part on the input signal, determine a second duration of a time period for the drive signal based at least in part on the first duration, and keep the drive signal at a first logic level during the entire time period.

Abstract: System and method for regulating a power conversion system. A system controller for regulating a power conversion system includes a first controller terminal and a second controller terminal. Additionally, the system controller is configured to receive an input signal at the first controller terminal, and generate a drive signal at the second controller terminal based at least in part on the input signal to turn on or off a transistor in order to affect a current associated with a secondary winding of the power conversion system. Moreover, the system controller is further configured to determine whether the input signal is larger than a first threshold at a first time, in response to the input signal being determined to be larger than the first threshold at the first time, determine whether the input signal is smaller than a second threshold at a second time.

Abstract: System and method for protecting a power converter. The system includes a duty-cycle detection component configured to receive a modulation signal, determine a first duty cycle corresponding to a first period of the modulation signal, compare the first duty cycle with a threshold duty cycle, and generate a duty-cycle comparison signal. Additionally, the system includes a threshold generator configured to receive the duty-cycle comparison signal and generate a threshold signal corresponding to a second period of the modulation signal, the second period being after the first period, and a comparator configured to receive the threshold signal and a first signal and to generate a first comparison signal. The first signal is associated with an input current for a power converter. Moreover, the system includes a pulse-width-modulation component configured to receive the first comparison signal and generate the modulation signal for adjusting the input current for the power converter.

Abstract: System and method for regulating a power conversion system. An example system controller includes: a first controller terminal and a second controller terminal. The system controller is configured to: receive an input signal at the first controller terminal and generate a first drive signal at the second controller terminal based on at least information associated with the input signal to turn on or off a transistor to affect a current associated with a secondary winding of the power conversion system. The system controller is further configured to: in response to the input signal changing from a first value larger than a first threshold to a second value smaller than the first threshold, change the first drive signal from a first logic level to a second logic level to turn on the transistor.

Abstract: System and method for protecting a power converter. The system includes a first comparator configured to receive a first threshold signal and a first signal and to generate a first comparison signal. The first signal is associated with an input current for a power converter. Additionally, the system includes a second comparator configured to receive a second threshold signal and the first signal and to generate a second comparison signal. The second threshold signal is different from the first threshold signal in magnitude. Moreover, the system includes a first detection component configured to receive at least the second comparison signal, detect the second comparison signal only if one or more predetermined conditions are satisfied, and generate a first detection signal based on at least information associated with the detected second comparison signal.

Abstract: System and method for regulating a power converter. The system includes a first signal generator configured to receive a first sensed signal and generate an output signal associated with demagnetization. The first sensed signal is related to a first winding coupled to a secondary winding for a power converter, and the secondary winding is associated with at least an output current for the power converter. Additionally, the system includes a ramping signal generator configured to receive the output signal and generate a ramping signal, and a first comparator configured to receive the ramping signal and a first threshold signal and generate a first comparison signal based on at least information associated with the ramping signal and the first threshold signal. Moreover, the system includes a second comparator configured to receive a second sensed signal and a second threshold signal and generate a second comparison signal.

Abstract: System and method for regulating a power conversion system. A system controller for regulating a power conversion system includes a first controller terminal and a second controller terminal. Additionally, the system controller is configured to receive an input signal at the first controller terminal, and generate a drive signal at the second controller terminal based at least in part on the input signal to turn on or off a transistor in order to affect a current associated with a secondary winding of the power conversion system. Moreover, the system controller is further configured to determine whether the input signal is larger than a first threshold at a first time, in response to the input signal being determined to be larger than the first threshold at the first time, determine whether the input signal is smaller than a second threshold at a second time.

Abstract: System and method for regulating a power conversion system. An example system controller includes: a first controller terminal and a second controller terminal. The system controller is configured to: receive an input signal at the first controller terminal and generate a first drive signal at the second controller terminal based on at least information associated with the input signal to turn on or off a transistor to affect a current associated with a secondary winding of the power conversion system. The system controller is further configured to: in response to the input signal changing from a first value larger than a first threshold to a second value smaller than the first threshold, change the first drive signal from a first logic level to a second logic level to turn on the transistor.

Abstract: System and method for dimming control. The system includes a system controller including a first controller terminal and a second controller terminal, a transistor including a first transistor terminal, a second transistor terminal and a third transistor terminal, and a resistor including a first resistor terminal and a second resistor terminal. The system controller is configured to generate a first signal at the first controller terminal based on an input signal and to generate a second signal at the second controller terminal based on the first signal. The first transistor terminal is coupled to the second controller terminal. The first resistor terminal is coupled to the second transistor terminal. The second resistor terminal is coupled to the third transistor terminal. The transistor is configured to receive the second signal at the first transistor terminal and to change between two conditions in response to the second signal.