公开(公告)号：US11990840B2

公开(公告)日：2024-05-21

申请号：US17840864

申请日：2022-06-15

Applicant: Leadtrend Technology Corporation

Inventor： Yao-Tsung Chen ,  Kuan-Hsien Chou

IPC: H02M3/335 ,  H02H7/12 ,  H02M1/00 ,  H02M3/00 ,  H02M3/24

CPC classification number: H02M3/24 ,  H02H7/1213 ,  H02M1/0009 ,  H02M3/01

Abstract: A control method is disclosed to prevent false triggering of over-current protection. A power converter comprises high-side and low-side switches connected in series between an input power line and a ground line, for driving a resonant circuit to resonate. The power converter includes a detector detecting the resonant circuit to provide a detection signal representing a magnitude of resonance in the resonant circuit. A duty cycle of one of the high-side and low-side switches is detected, and a threshold is determined in response to the duty cycle. An over-current protection is triggered based on the threshold and the detection signal. When the over-current protection is triggered, at least one of the high-side and low-side switches stops providing power to the resonant circuit, and the resonance subsides.

公开(公告)号：US20230344356A1

公开(公告)日：2023-10-26

申请号：US18067846

申请日：2022-12-19

Applicant: Leadtrend Technology Corporation

Inventor： Hsin Hung LU ,  San-Yi LI ,  Hung-Ting HSU

IPC: H02M3/335 ,  H02M1/08

CPC classification number: H02M3/33523 ,  H02M1/08

Abstract: A control method is disclosed to have a voltage sample capable of more correctly representing an output voltage of a power converter. The power converter has a primary side and a secondary side galvanically isolated from each other. A feedback voltage is received in the primary side. A main power switch is turned OFF, starting an OFF time, during which the feedback voltage is constrained in response to the voltage sample. In a sampling time within the OFF time, the feedback voltage is sampled to update the voltage sample representing the output voltage in the secondary side. A driving signal is provided in response to the voltage sample to control the main power switch.

公开(公告)号：US11791737B2

公开(公告)日：2023-10-17

申请号：US17548957

申请日：2021-12-13

Applicant: Leadtrend Technology Corporation

Inventor： Tsung-Chien Wu ,  Chung-Wei Lin ,  Ming-Chang Tsou ,  Jun-Hao Huang

IPC: H02M3/335

CPC classification number: H02M3/33592 ,  H02M3/33507

Abstract: The invention discloses a control method in use of a synchronous rectifier controller, controlling a synchronous rectifier in a power supply supplying power a load. The synchronous rectifier is turned ON in response to a terminal signal of the synchronous rectifier. An ON-time of the synchronous rectifier is made not less than a minimum ON-time. A detection result in association with the load is provided, for determining the minimum ON-time. The minimum ON-time is a first period when the detection result indicates the load as a first load, and a second period, shorter than the first period, when the detection result indicates the load as a second load heavier than the first load.

公开(公告)号：US10797591B2

公开(公告)日：2020-10-06

申请号：US16674183

申请日：2019-11-05

Applicant: Leadtrend Technology Corporation

Inventor： Ming Chang Tsou ,  Meng Jen Tsai

IPC: H02M1/44 ,  H02M3/335 ,  H02M1/08 ,  H02M1/00

Abstract: A power controller disclosed is for the use of a power converter with an inductive to regulate an output power source. The power controller has a PWM signal generator and a jitter inducer. The PWM signal generator controls a power switch to generate consecutive switching cycles. In each switching cycle the PWM signal generator controls a peak to regulate the output power source, and the peak is capable of representing a current flowing through the inductive device. The jitter inducer, connected to the PWM signal generator, is for altering the peak, so as to make a difference between two consecutive peaks. The difference has a sign and a magnitude. The jitter inducer makes the sign changed switching cycle by switching cycle.

公开(公告)号：US10666153B2

公开(公告)日：2020-05-26

申请号：US16549063

申请日：2019-08-23

Applicant: Leadtrend Technology Corporation

Inventor： Yao Tsung Chen ,  Chih Chi Chang ,  Meng Jen Tsai

IPC: H02M3/335

Abstract: A control method for a power convert is disclosed. The power convert uses an active-clamp flyback topology and has low-side and high-side switches. The low-side switch is switched to generate consecutive switching cycles including a modified flyback cycle and a normal flyback cycle. Each of the consecutive switching cycles is not less than a blanking time generated in response to a load of the power converter. The high-side switch is constantly turned OFF during the normal flyback cycle. The high-side switch is turned ON after the blanking time during the modified flyback cycle to perform zero-voltage switching for the low-side switch.

公开(公告)号：US09730283B2

公开(公告)日：2017-08-08

申请号：US15018755

申请日：2016-02-08

Applicant: Leadtrend Technology Corporation

Inventor： Ching-Tsan Lee

IPC: H05B37/00 ,  H05B33/08

CPC classification number: H05B33/0815 ,  H05B33/083 ,  H05B33/0887 ,  Y02B20/341

Abstract: The disclosure regards to drivers and driving methods for a LED string consisting of LEDs. The LED string and a current switch are coupled in series between a power line and a ground line. The power line is powered to regulate a signal representing a current passing through the LED string. An enable signal capable of switching the current switch is provided. Whether a predetermined event occurs is detected. When the predetermined event occurs, the enable signal is clamped to have a predetermined logic value, the current switch thereby being kept either open or short.

公开(公告)号：US09723664B2

公开(公告)日：2017-08-01

申请号：US14725045

申请日：2015-05-29

Applicant: Leadtrend Technology Corporation

Inventor： Chang Yi Lin ,  Kuo Chien Huang ,  Chi Pin Chen

IPC: H05B33/08

CPC classification number: H05B33/0815 ,  H05B33/0845 ,  H05B33/0887

Abstract: Control methods and apparatuses providing a holding current for a TRIAC dimmer are disclosed. A control method is suitable for a power controller powered by an operation power source. A high-voltage device in the power controller is connected between the operation power source and an input power source, from which the high-voltage device drains a conduction current. An operation voltage of the operation power source is detected, and, during a startup procedure, the conduction current is forwarded to charge the operation power source. A detected voltage representing an input voltage of the input power source is provided, and if the detected voltage is below a setting voltage, the conduction current is forwarded to a ground line instead of charging the operation power source.

公开(公告)号：US09621027B2

公开(公告)日：2017-04-11

申请号：US14478955

申请日：2014-09-05

Applicant: Leadtrend Technology Corporation

Inventor： Chang-Yi Lin ,  Yi-Chuan Tsai

IPC: H02M1/42 ,  H02M1/00

CPC classification number: H02M1/4225 ,  H02M1/42 ,  H02M1/4208 ,  H02M2001/0032 ,  Y02B70/126 ,  Y02B70/16

Abstract: An apparatus is capable of improving the power factor of a power supply powered by a high power line and a ground power line. The apparatus comprises a line voltage detector and an ON time controller. The line voltage detector provides a scaled voltage to represent a line voltage of the high power line. The ON time controller has a valley voltage detector, which provides, in response to the scaled voltage, a valley representative representing a valley voltage of the line voltage. The ON time controller controls an ON time of a power switch in the power supply in response to the valley representative.

公开(公告)号：US09608531B2

公开(公告)日：2017-03-28

申请号：US14604843

申请日：2015-01-26

Applicant: Leadtrend Technology Corporation

Inventor： Chung-Wei Lin ,  Yang-Sheng Lin ,  Wen-Chung Yeh

IPC: H02M3/335 ,  H02M1/08

CPC classification number: H02M3/33592 ,  H02M1/08 ,  H02M3/335 ,  H02M3/33507 ,  Y02B70/1475

Abstract: A timing controller provides adaptive timings to control a synchronous rectifier with a body diode. The timing controller has a ramp generator providing a ramp signal at a first capacitor. The ramp signal corresponds to a discharge time when the body diode is forward biased. A second capacitor records an estimated duration signal. An update circuit is connected between the first and second capacitors, for shorting the first and second capacitor to update the estimated duration signal by charge sharing. A comparator with two inputs coupled to the ramp signal and the estimated duration signal respectively compares the ramp signal and the estimated duration signal to control the synchronous rectifier.

公开(公告)号：US09077250B2

公开(公告)日：2015-07-07

申请号：US13833699

申请日：2013-03-15

Applicant: Leadtrend Technology Corporation

Inventor： Yu-Yun Huang ,  Yi-Lun Shen

IPC: H02M3/335

CPC classification number: H02M3/33507

Abstract: Herein is disclosed a constant current control unit and a control method, for a switched mode power supply with primary side control. The switched mode power supply comprises a power switch and an inductive device. A reflective voltage of the inductive device is detected to generate a feedback voltage signal. By delaying the feedback voltage signal, a delayed signal is generated. According to the feedback voltage and the delayed signal, a discharge time of the inductive device is determined when the power switch is OFF. According to the discharge time and a current-sense signal, a maximum average output current of the switched mode power supply is stabilized. The current-sense signal represents a current flowing through the inductive device.

Abstract translation: 这里公开了一种具有初级侧控制的开关式电源的恒流控制单元和控制方法。 开关模式电源包括电源开关和感应装置。 检测感应装置的反射电压以产生反馈电压信号。 通过延迟反馈电压​​信号，产生延迟的信号。 根据反馈电压和延迟信号，当电源开关关闭时，确定感应装置的放电时间。 根据放电时间和电流检测信号，开关模式电源的最大平均输出电流稳定。 电流检测信号表示流过电感器件的电流。