PWM Chopper of Ultrasonic Power Supply Based on FPGA

2012 ◽  
Vol 476-478 ◽  
pp. 1305-1308
Author(s):  
Chun Feng Sun ◽  
Wei Guang Zhang

Pulse width modulation (PWM) is often one of the important power regulation method of ultrasonic power supply. The traditional PWM control circuit has the shortcomings of complex design structure, slow dynamic response and low reliability. An advanced PWM technique for choppers of ultrasonic power supply based on FPGA is proposed. Through open-loop operation, it regulates the output pulse width of ultrasonic power supply dynamically. The simulation result shows that the PWM control circuit based on FPGA can realize to adjust the width of PWM signal and power regulation conveniently.

2014 ◽  
Vol 625 ◽  
pp. 593-596
Author(s):  
Yoshiki Takeda ◽  
Yuki Hata ◽  
Katsuyoshi Endo ◽  
Kazuya Yamamura

Plasma chemical vaporization machining (PCVM) is an ultraprecise figuring technique for optical components without introducing the subsurface damage. In our previous study, the material removal volume was controlled by changing the scanning speed of the worktable. However, because of inertia of the worktable, a discrepancy between the theoretical scanning speed and the actual scanning speed will occur if the spatial change rate of speed is rapid. Therefore, we proposed the application of the pulse width modulation (PWM) control and the amplitude modulation (AM) control of the applied RF power to control the material removal rate (MRR). Experimental results showed that the relationship between the MRR and the average RF power had high linearity, the control range of the PWM control mode was from 0.19 x 10-2 mm3/min to 3.90 x 10-2 mm3/min (from 5% to 100%), which was much wider than that of the AM control mode.


2015 ◽  
Vol 771 ◽  
pp. 145-148 ◽  
Author(s):  
Muhammad Miftahul Munir ◽  
Dian Ahmad Hapidin ◽  
Khairurrijal

Research on nanofiber materials is actively done around the world today. Various types of nanofibers have been synthesized using an electrospinning technique. The most important component when synthesizing nanofibers using the electrospinning technique is a DC high voltage power supply. Some requirements must be fulfilled by the high voltage power supply, i.e., it must be adjustable and its output voltage reaches tens of kilovolts. This paper discusses the design and development of a high voltage power supply using a diode-split transformer (DST)-type high voltage flyback transformer (HVFBT). The DST HVFBT was chosen because of its simplicity, compactness, inexpensiveness, and easiness of finding it. A pulse-width modulation (PWM) circuit with controlling frequency and duty cycle was fed to the DST HVFBT. The high voltage power supply was characterized by the frequency and duty cycle dependences of its output voltage. Experimental results showed that the frequency and duty cycle affect the output voltage. The output voltage could be set from 1 to 18 kV by changing the duty cycle. Therefore, the nanofibers could be synthesized by employing the developed high voltage power supply.


Author(s):  
Nor A. Azmi ◽  
Sohiful A.Z. Murad ◽  
Azizi Harun ◽  
Rizalafande C. Ismail

Background: This paper describes the design of 5 V to 6 kV DC-DC converter by using a switching regulator with Cockroft-Walton (C-W) voltage multiplier for a high voltage power supply module. Methods: The proposed design consists of Pulse Width Modulation (PWM) controller circuit, voltage multiplier, and feedback signal. A single unit of 5 V input triggers LT1618 controller circuit to generate 20 V which then produces 300 V from LT8331 output that is connected to diode-capacitor multiplier circuit to achieve final 6 kV. A negative feedback signal is required to stabilize an output voltage. With the implementation of C-W voltage multiplier technique, the output is boosted up as required from the input signal voltage 5 V DC. Results: The LTspice simulation results indicate that the proposed DC converter can generate 6.20 kV. Line regulation of 17 % and the load regulation of 14 % are obtained based on the proposed design. Conclusion: The proposed design is suitable for high voltage power supply module.


2014 ◽  
Vol 912-914 ◽  
pp. 927-930
Author(s):  
Qiang Jiang

In this paper, a HV and HF switch power supply was designed, which was controlled through a single chip microcomputer, also the MOSFET was used as the switch power tube. The PWM (pulse width modulation) technique and half-bridge inverter topology have been used to invert AC into the DC that can be adjust from 0V~25KV and the operating frequency is 35KHz, Through the simulation with the Saber software and practical use, the feasibility of the scheme and the correctness of the design have been verified.


Author(s):  
Taha A. Hussein ◽  
Laith A. Mohammed

Space vector pulse width modulation (SVPWM) generates less harmonic distortion in the output voltage or currents, provides more efficient use of supply voltage and better voltage utilization compared with sine pulse width modulation (PWM). In this work, a detailed Simulink implementation for SVPWM for the open loop control of permanent magnet synchronous motor (PMSM) is presented. Results show the output of the blocks that assembles SVPWM besides the PMSM voltages and currents when exposing the motor to different load torques. The technique of SVPWM enables the load to respond to the change in external load torque. This technique also results in lower total harmonic distortion and better utilization of the direct current (DC) supply compared with traditional sinusoidal pulse width modulation sinusoidal pulse width modulation (SPWM).


Author(s):  
SUNIL KUMAR. M ◽  
S. G. SRIVANI ◽  
VENKATESH PRABHU

In High Power Pulsed Radar Transmitters the gridded TWT are used and consists of floating deck modulator unit which houses the Grid and Filament power supplies. The Grid Control includes the Grid Positive & Grid Negative Power Supplies. The Positive voltage is used to turn on the TWT & Negative voltage is used to operate the TWT in off state. The Filament power supply heats the cathode to required temperature to emit electrons. The aim of the project is to design the Grid power supplies and Filament Power supply based on the Fly back Converter topology which is operated at 100 KHz in DCM mode and CCM mode respectively. The Pulse width modulation technique is used to maintain the voltage at desired value using an IC UC1526.The switching device is protected ag


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