Since some card has burned out I wanted to check the temperatures of various points. I noticed a strange thing: why the temperature of the two MOSFETs is very different? a mosfet to about 110 degrees and the other body to about 35 degrees.
The coil gets to about 45 degrees with all the power from 50 0 50.
The mosfets are 4227 Monto irfb23n20d while if the temperature rises to 110 degrees while the other one remains at 35 degrees.
The coil gets to about 45 degrees with all the power from 50 0 50.
The mosfets are 4227 Monto irfb23n20d while if the temperature rises to 110 degrees while the other one remains at 35 degrees.
can you elaborate more, very hard for us to get the real picture... which side is hotter is it the high side or lower side mosfet... can you provice schematic or photo
Could be a problem with the high side power supply causing the mosfet to go into the linear region.
reducing the frequency get these temperatures:
low side MOSFET 70 degrees, the high side mosfet always 30, inductance 50 degrees.
Is this normal? for the mosfet where can i see?
low side MOSFET 70 degrees, the high side mosfet always 30, inductance 50 degrees.
Is this normal? for the mosfet where can i see?
mosfet normally must have the same temperature?
roughly what?
in the project there are no resistors on the gate of the mosfet ... what do you think?
I did a test to add, but the problem of the temperature difference remains.
roughly what?
in the project there are no resistors on the gate of the mosfet ... what do you think?
I did a test to add, but the problem of the temperature difference remains.
The temperatures should be the same.
What have you set the dead time to ?
Too short a dead time will heat up the mosfets.
What have you set the dead time to ?
Too short a dead time will heat up the mosfets.
10k +10k for dead time.
I did try to use the same values of 3.3 + 8.2 datasheet but the temperature does not change. reducing the resistance of the PWM frequency the temperature drops a lot. of defual there are two capacitors from 1000nF and the resistor 360. putting a resistor 170 the temperature from 110-120 drops to 80. with 120 ohms the temperature drops to 60-70 (the other mosfet always 30)
I did try to use the same values of 3.3 + 8.2 datasheet but the temperature does not change. reducing the resistance of the PWM frequency the temperature drops a lot. of defual there are two capacitors from 1000nF and the resistor 360. putting a resistor 170 the temperature from 110-120 drops to 80. with 120 ohms the temperature drops to 60-70 (the other mosfet always 30)
What size heat sink are you using ? Seems odd you are getting 2 different temperatures on the mosfets.
I did try to mount a heatsink twice that of the default and the temperatures remain those, 70 and 30., without touching the pwm frequency of the gap is greater than 120 vs 30
resistance on pin for the gate of the MOSFET are important? I have to mount them?
50 degrees on the coil are excessive?
50 degrees on the coil are excessive?
What value gate resistors are you using ?
I use 10ohms.
My coil barely gets warm, I use a t106-2 core with about 13 turns on it.
I use 10ohms.
My coil barely gets warm, I use a t106-2 core with about 13 turns on it.
defaul is 0...i actually use 10 ohm.
how i can see for high side mosfet?
the problem is on high side (around 30 C) or in low side (actually 70)?
how i can see for high side mosfet?
the problem is on high side (around 30 C) or in low side (actually 70)?
forgive the ignorance. gate driver you mean a dedicated chip? I have not. the schematic is similar to iraudamp 7.
the supplier does not want to give me the schematic.
the supplier does not want to give me the schematic.
Last edited:
For iraudamp7 you need something like irfb4019 mosfets with low gate capacitance.
If you are using irfb4227 then the 2092 isn't powerful enough to drive them.
With irfb4227 you need npn/pnp buffer or a tc4420 buffer.
The 4227 has a high gate capacitance.
- Status
- Not open for further replies.