power electronics

  1. meshcurrent

    How to select a mosfet driver(opto..) for 24v to 12v buck converter

    I want to create a 24v to 12v buck converter. I am trying to control mosfet with optocouplör. I have 25kHz-50kHz pwm signal from arduino/pic16f877A. I have some mosfets like IRFZ44N, IRF540N IRF4905 and etc. I am using PC817 opto but I guess it is not suitable for high frequency pwm like 25kHz...
  2. L

    Question about a control logic needed to be implemented

    Hello everybody.I have to implement the in house circuit cc-ih circuit which is an energy harvester circuit using simscape electrical. The description of the circuit can be found on page 7 of the pdf at Finite element-based assessment of energy harvesting in composite beams with piezoelectric...
  3. M

    R/S flip flop usage in DC/DC converters

    Hi Everyone, Can anybody explain why R/S flip flop is used in this circuit? I would also like to know how the clock signal should look like in duty cycle? Last but not least, in R/S flip flop's truth table, it's stated that both set and reset pins shouldn't be turned to high state at the same...
  4. B

    Buck Boost Converter with MOSFET

    Hello all, Disclosure, I am an electrical engineer but I deal with designing power system for construction projects. I decided to go back for Masters in Power Electronics. I'm rusty with DC circuits. My homework is the same as a previous thread...
  5. alobaolalekann

    Question about Current Draw and Spikes in Half-Bridge Switching Circuit with RC-Snubber

    Is it okay if the half-bridge switching circuit draws up to 100mA from the power supply at 20kHz because of the RC-snubber between the MOSFETs' drain and source? Without the snubber parts, there's no noticeable current draw, but there are many spikes in the output.
  6. alobaolalekann

    MOSFET testing Issues

    I'm currently encountering difficulties in testing my MOSFETs. I am in the process of designing a snubber for an IRF840 operating at 20kHz. Upon attempting to test (drive) the MOSFET, at <= 50% duty, in its basic state without any additional circuitry, I observed a 4V voltage drop from the 12V...
  7. S

    Low frequency oscillation induced during CCPS discharge.

    Hello all, I am designing a CCPS and using a phase-shifted, series-resonant bridge as the switching topology. There is a DC block capacitor in series with the transformer primary winding. When the target voltage is reached, the H-bridge switches are turned off until a command for the next...
  8. riccmez

    Can't find out what component it is exactly

    Hello, I'm trying to simulate an AC/DC converter for a class project. Now, this was an assigned circuit there isn't much I can do about the design. There's on component that I can't quite figure out. as far as I researched I understand that it is a sort of bidirectional thyristor but don't...
  9. VektorElektor

    Buck Converter Simulation in Python

    Hey everybody, first time here! As a personal project I am implementing a Buck Converter simulation in Python. My basic idea is to give a constant Vs supply and simulate the switch on/switch off steps in each switching period, calculate the increase/decrease in inductor current and calculate an...
  10. dr3iz

    How to connect PMOS in parallel

    Hi, we are designing a 48V high side MOSFET switch and we realised that the our mosfet gets too hot. Our solution is to connect additional mosfets in parallel to distribute the load/heat. But I'd like to ask your how to properly connect PMOS in parallel. I read somewhere that the gates should...
  11. -live wire-

    DIY E-Scooter help - electronic breaking, pcb design

    Hi, I'm a rising freshman at Case Western University, and I would like to make an an electronic scooter to get around campus before I move in in about two months (mid august 2023). I already have a lot of the parts I would need for the project, like motors and motor controllers, among other...
  12. S

    4-20ma to 0-3.3V conversion using Rail to rail Opamp

    I am trying to convert 4-20 mA current loop signal to 0-3.3/0-3 V output for my 10 bit ADC IC that is connected to a Raspberry pi 3B+. Schematic: The input sensor is a 12 V loop powered 4-20 mA output humidity sensor. The op-amp is an MCP6002 rail-to-rail. The output of the op-amp is...
  13. B

    LLC converter working above resonance

    Hello I am designing LLC Half-Bridge converter. Pout = 500W Out= 12V Vin=390V Fr = 80kHz Lr = 30 uH, Cr = 120nF , Lp = 190uH The converter is working always above resonant frequency. The oscillographs you see are measured in 200W Pout. As you can see the green channel is Lr current, red channel...
  14. A

    Gate-source voltage waveform in brushless motor drive

    What should be the gate-source voltage waveform of the high side MOSFETs in a brushless motor drive with a trapezoidal control method? Are these parts marked in red in the picture above normal? There is no such thing at the bottom side MOSFETs Schematic: When I reduce the value of R47 and...
  15. kwoki

    Power dissipation of synchrononous buck converter cannot be reduced with gate drivers?

    Hi guys, For this project, I had to want to reduce the power dissipation (< 2 mW) when the Rload is 54 Ω. These are the two circuits that I have employed. When I sweep the pwm frequency vs Pdiss (power dissipation of the buck converter), without/with the gate driver, I have the following...
  16. jbHardwareDev

    Dual mosfet switch problem

    Hi. I plan to make a pcb that drives peltier and heating pad. Only one of those works at the same time. Load elements are parallel to capacitors. I have very little space on pcb so it would be nice if I could use only one inductor as it is in screenshot. I know it would be easier just to put...
  17. C

    The Question about MOSFET Library Parameters in LTSpice

    Hi I am doing a double pulse test of MOSFET (PN: IAUS300N08S5N012TATMA1). Since we have high voltage spikes and oscillation of Vds in hardware testing, I am also working on LTSpice of double pulse test. I am so confused about the parasitic parameter of the MOSFET lib, I know the MOSFET has...
  18. C

    Thermal Design Question about Multiple MOSFETs paralleled for Single Cold Plate

    I am a student in power electronic filed. When I design PCB and calculate the junction temperature of MOSFET, I am very confused about the thermal design question. My PCB design is here: (in the middle of the figure) : three MOSFETs in parallel, so 12 MOSFETs(Rthj-c=0.4 from datasheet) in one...
  19. AhmedKhouaja

    MOSFET Power Loss calculation ?

    Dear All About Circuits Team, I hope everyone is doing well, I have a question about the MOSFET's behaviour, How can I figure out how much heat the Mosfet produces per amp and how much current it can consume when acting as a load? Below, the Mosfet application shown in the figure, it's an...
  20. S

    Capacitor calculation with real and imaginary parts for a resonant converter

    Hi All, I have designed a resonant LCC converter for my thesis. It has been some time since I visited the theory and believe I used the following document by Robert Steigerwald to select the resonant components: IEEE Xplore Full-Text PDF: I was attempting to rearrange this equation for the...
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