Peer-to-peer, engineer-to-engineer questions and answers from the EDABoard.com engineering community around power electronics. Click the “Read more” link and follow the entire conversation and maybe add your two cents by logging in to EDAboard.com

Problem with inverter’s drive – I tried to build this configuration but when I try to raise the voltage up to 12 volts the IC IR2110 (which drive (third switches) IGBT ) burn. Is the problem in the drive circuit? The drive circuit and the IGBT configuration is attached. Read more

Inverter sinewave problem – I am trying to remake an inverter which previously designed with IPM. I redesign it with MOSFETs instead of IPM, and I use push-pull topology. I change the PWM pulse width while reading the input voltage of the inverter. Actually I think there is nothing wrong with PWM since if there is load at the output, there is no problem at all. But if there is no load at the output of inverter my sinewave is not as expected as you can see below. Read more

Parallel connection of multiple half-bridge – I want to build a 15Kw DC motor driver. Is it possible to design five 3Kw half-bridge motor driver and connect them in parallel? Read more

Controlling multiple power LED drivers – I have a couple of power LEDs, which I intend to control with an Arduino (not directly, with transistors), to achieve chase lights or other patterns. After trying different resistors, I gave up because of the heat problems. I found the following circuit in an ON Semiconductor application brief. Read more

SOA of MOSFET….the meaning of “DC” in the graph – In the graph of SOA in the SPB07N60C3 FET datasheet (pg 5), I presume the “DC” means “duty cycled,” or “Direct Current”…in other words “pulse trains” or continuous DC? Read more

Parallel connection of multiple LLC converters – I am trying to parallel 6 LLC converters each having their own synchronous rectification. Each converter has its own frequency control, so each has a different phase and amplitude with respect to each other. Each converter has its own closed loop voltage and current control. So a runaway of a single converter in the group is unlikely. Read more

Earthing and EMC of offline SMPS – Please could anyone elaborate on the meanings of various things in this (attached) document on Earthing & EMI Filters? The document is called “Safety concerns for practical EMI line filters“. Read more

Unknown device in a high voltage chopper – I am curious to know what are the circled devices… Read more

Serious IGBT overshoot -I’m working on a power-supply but have run into some serious overshoot problems. As you can see I tried with an RCD snubber, but that didn’t change anything, do you perhaps have any suggestions on how to deal with this? Read more

H-bridge current spike – I’m simulating the following a class D amplifier as shown in the image. The PWM driving scheme is bipolar (25 kHz), the load is 20mH+1.9R, the driving resistors, and the dead time (250ns) correspond to those of the gate driver I choose. The actual transistor I’ll be using is the CSD18540Q5B, but as there is no open spice model of it, I’m simulating with the IPB090N06N3 which seems to be similar. The problem I find is that simulation shows a current spike on the lower transistor each time it turns on. Do you know where it might come from? Read more