A novel constant current control circuit for a primary-side controlled AC-DC LED driver

2014 ◽  
Author(s):  
Yao Chen ◽  
Changyuan Chang ◽  
Penglin Yang
Keyword(s):  
Current Control ◽  
Control Circuit ◽  
Constant Current ◽  
Led Driver

scholarly journals LLC LED Driver with Current-Sharing Capacitor Having Low Voltage Stress

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 112
Author(s):  
Wen-Zhuang Jiang ◽  
Kuo-Ing Hwu ◽  
Jenn-Jong Shieh
Keyword(s):  
Low Voltage ◽  
Light Emitting Diode ◽  
Input Voltage ◽  
Current Control ◽  
Constant Current ◽  
Resistive Load ◽  
Led Driver ◽  
Current Sharing ◽  
Voltage Stress ◽  
The Difference

In this paper, an LLC light-emitting diode (LLC LED) driver based on the current-sharing capacitor is presented. In the proposed LED driver, the LLC resonant converter is used to step down the high input voltage, to provide galvanic isolation, to offer a constant current for LEDs. Moreover, the current-sharing capacitor connected to the central-tapped point of the secondary-side winding is used to balance the currents in two LED strings. By doing so, the voltage stress on this capacitor is quite low. Above all, the equivalent forward voltages of the two LED strings are generally influenced by the temperature and the LED current, and this does not affect the current-sharing performance, as will be demonstrated by experiment on the difference in number of LEDs between the two LED strings. In addition, only the current in one LED string is sensed and controlled by negative feedback control, while the current in the other LED string is determined by the current-sharing capacitor. Moreover, this makes the current control so easy. Afterwards, the basic operating principles and analyses are given, particularly for how to derive the effective resistive load from the LED string. Eventually, some experimental results are provided to validate the effectiveness of the proposed LED driver.

30A/60V Electric Car Charger Control Circuit Simulation

2014 ◽  
Vol 971-973 ◽  
pp. 950-953
Author(s):  
Ying Chun Liu ◽  
Jian Ming Zhang ◽  
De Long Zhang ◽  
Yan Yu Wang ◽  
Chun Guang Hou ◽  
...  
Keyword(s):  
Operational Amplifier ◽  
Circuit Simulation ◽  
Characteristic Curve ◽  
Rechargeable Batteries ◽  
Current Control ◽  
Control Circuit ◽  
Constant Current ◽  
Constant Voltage ◽  
Op Amp ◽  
Charging Mode

Through analysis and comparison of existing charging method works , adding more links constant current charging and constant voltage charging on the basis of the three-stage charging mode is proposed to receive more in line with rechargeable batteries five-phase characteristic curve charging mode. By scaling the control circuit and the PI regulator circuits use the charging current value and the constant voltage is sampled , a constant voltage corresponding to the error value to be compared and outputs the PWM control chip SG3525, causing the output current of the front end circuit chip , the regulation voltage , the error is gradually reduced until it reaches the steady-state output . 1 key components - integrated operational amplifier selection Integrated operational amplifier control circuit for the main components , essentially the entire op-amp circuits are designed to carry around , so choose the op amp circuit is particularly important . From the foregoing analysis, the current control and voltage control portion of each part requires three op amp ( both as an amplifier , a PI controller is used ) , the entire control circuit requires access to six integrated amplifier . Out of circuit integration considerations, decided to use a quad op amp manifold and a dual op amp with the completion of the manifold . By screening and the corresponding parameters available on the TI (TEXAS INSTRUMENTS TI ) website , and ultimately determine the use of quad op amp LF347 and dual op amp TLC2272.

scholarly journals Wireless constant current control circuit for LED light source in PSD test system

2020 ◽  
Vol 3 (1) ◽  
pp. 1
Author(s):  
Feixiang Ruan ◽  
Pengrong Hou ◽  
Xudong Hao ◽  
Yihan Luan ◽  
Xiaohong Lu
Keyword(s):  
Light Source ◽  
Test System ◽  
Current Control ◽  
Control Circuit ◽  
Constant Current ◽  
Led Light

scholarly journals Simple LED driver with Constant Current Control

2014 ◽  
Vol 3 (4) ◽  
pp. 422-427
Author(s):  
Seong-Mi Park ◽  
Sung Geun Song ◽  
Sang Hun Lee
Keyword(s):  
Current Control ◽  
Constant Current ◽  
Led Driver

scholarly journals Optimization of a Series Converter for Low-Frequency Ripple Cancellation of an LED Driver

Electronics ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 664 ◽  
Author(s):  
Jorge Garcia ◽  
Sarah Saeed ◽  
Pablo Quintana ◽  
Jesus Cardesin ◽  
Ramy Georgious ◽  
...  
Keyword(s):  
Low Frequency ◽  
Current Control ◽  
Buck Converter ◽  
Constant Current ◽  
Led Driver ◽  
Original Proposal ◽  
Voltage Ripple ◽  
Power And Control ◽  
Optimization Methodology ◽  
And Control

In this paper, the optimization of the power and control stages of a previously proposed topology for an off-line LED electronic driver is presented. The full system avoids the use of electrolytic capacitors at the D C link, therefore increasing the lifespan and reliability of the driver. As a consequence of having a relatively small capacitance, the D C link operates with a large Low-Frequency ( L F ) voltage ripple. This work presents a design optimization for the power and control stages of a current-fed bidirectional buck converter, operating as the LED current control stage. As this block processes only the A C power arising from the L F voltage ripple, it can increase the system efficiency against the typical two-stage solution. In the original proposal, the main drawback was the high inductor losses due to the resulting large inductor currents and large inductance value. The proposed optimization ensures an enhanced design of the inductor while keeping a constant current through the LEDs. A new optimization methodology is proposed and the theoretical results have been validated in a built prototype for a 40 W LED lamp.

Design and Implementation of Mid-Frequency Magnetron Sputtering Power Supply Based on TL494 and MCU

2013 ◽  
Vol 709 ◽  
pp. 408-412
Author(s):  
Yan Ling Zhao ◽  
Rong Xing Liu
Keyword(s):  
Magnetron Sputtering ◽  
Power Supply ◽  
Current Mode ◽  
Voltage Regulation ◽  
Control Circuit ◽  
Constant Current ◽  
Loop Control ◽  
Pulse Width Modulator ◽  
Digital Pulse ◽  
The Stability

Abstract. A mid-frequency magnetron sputtering (MFMS) power supply based on TL494 and MCU was introduced. A Buck Chopper and full bridge inverter were applied to the main circuit. The PWM controller TL494 was used in the Buck voltage-regulation control circuit to realize closed loop control. The drive signal of the IGBT in full bridge inverter was based on precise digital pulse width modulator (DPWM) signal produced by the MCU M30290. The DPWM can be set by potentiometer so the power supply can output the square wave with adjustable frequency and duty cycle. The power supply was operated in constant current mode. For micro or strong arcing of the target, different safeguards were adopted by the control circuit. At last, the system test and experimental results show that the stability, reliability and tuning range of the MFMS power supply can meet the requirements of the magnetron sputtering coating.

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