I have found the problem, it turns out the frequency is less fitting with the trafo.saya replace the 20k to 33k. Do I need to change the gate resistor gate mr.silvio, ??
Hi mr.silvio, I have completed my project, but I have not tested it, there is a problem in my transformer, there is a ringing sound. Do I need to adjust snuber, or maybe protection card (OCP) I have not planted, ??https://drive.google.com/file/d/1opEscKsEdNXQebZP4UX9BRQylU53k8jJ/view?usp=drivesdk
Hi mr.silvio ,, i already have igbt stock IRG4PSC71UD ,, what if i use that instead of fgh60n60,, seems i should remove the mur460 diode.
Hi Upik, Looking at the data sheets it seems that the IGBTs are more or less the same in characteristics. What I did not find in FGH60N60 is the graph that shows the derating current versus frequency. In the data sheet of the IRG4PSC71UD the graph shows that at a switching frequency of 30Khz the collector current must not exceed 20 Amps. As it goes higher the lower the current capability.
You should also know that IGBTs do not like high switching frequencies and the higher it is the lower the current that they can handle.
A 3KW smps draws around 20amps but that will be only on peaks for a short time in an audio amplifier. IGBTs have a low forward voltage and dissipate less heat while switching. Mosfets on the other hand can handle faster switching frequencies.
Use the MUR460 diode as this will help the internal diode in the IGBT to dissipate less heat. Put it as close as possible to the IGBT on the pcb.
Lately I am helping a friend repairing professional amplifiers and from what I am seeing they have a lot of input capacitance and the rule of thumb that I told you about that you must have 1Uf per watt across 300v is all true. This seems to be more important than the output capacitance. One case for a 3K smps input capacitance has 3000uF across the 320v (10 capacitors of 1200uf X 200v) and 5000uf (5 X 1000uF X 100v) on each side of the double output of 85v (170v)
Well, Thanks mr.silvio ,,, what about the gate resistor, ?? is it with the same value, ??Can I replace the 1n4148 diode with 1n5819, ???