elZero
Newbie level 2
Hello everyone,
I am making a 15V 2A (30W) CCM flyback converter with UC3843 and the feedback loop is with PC817 and TL431. I am not getting any output power at all. I am testing it with a 100W 8 ohm resistor.
In my initial test, there was no output at the secondary. I made a few test and I found that the UC3843 was switching. In the process of doing this test, I mistakingly shorted some pin and there came the magi smoke. Oops!
I did necessary clean up retested the components, replaced the some components and then I realised I had connected the MOSFET the wrong way. I replaced the the MOSFET entirely and retested. Love and behold my inverter disconnected it's output and reconnected as soon as I switched of the DUT. That would be a short circuit to me so I checked the transformer and it was gone, probably due to the incident of the magic smoke that occurred earlier. I then wound another tansformer and replaced the bad one.
I put on the converter again but still I didn't get any outpt voltage but this time it didn't short out the inverter. I heard a sound like something sparked and I noticed the the bridge rectifier is gone. No physical damage though.
I do not know what is causing this problem. I need your help. Thanks.
ElZero.
- - - Updated - - -
Duty cycle was selected to be 0.4 so I did not add any extrnal vlotage ramp.
I am making a 15V 2A (30W) CCM flyback converter with UC3843 and the feedback loop is with PC817 and TL431. I am not getting any output power at all. I am testing it with a 100W 8 ohm resistor.
In my initial test, there was no output at the secondary. I made a few test and I found that the UC3843 was switching. In the process of doing this test, I mistakingly shorted some pin and there came the magi smoke. Oops!
I did necessary clean up retested the components, replaced the some components and then I realised I had connected the MOSFET the wrong way. I replaced the the MOSFET entirely and retested. Love and behold my inverter disconnected it's output and reconnected as soon as I switched of the DUT. That would be a short circuit to me so I checked the transformer and it was gone, probably due to the incident of the magic smoke that occurred earlier. I then wound another tansformer and replaced the bad one.
I put on the converter again but still I didn't get any outpt voltage but this time it didn't short out the inverter. I heard a sound like something sparked and I noticed the the bridge rectifier is gone. No physical damage though.
I do not know what is causing this problem. I need your help. Thanks.
ElZero.
- - - Updated - - -
Duty cycle was selected to be 0.4 so I did not add any extrnal vlotage ramp.