Hey all,
I'm trying to build a photography light and I've been running into an issue with my DC-DC boost converters burning out for a reason I can't identify.
The circuit is pretty simple: A 120W AC-DC power adapter is outputting 12V to the boost converter (LINK), which is bumping it up to 32V, with a constant-current limit of 3A. The boost converter is then outputting to a 100W LED chip rated for a forward voltage of 30-34V and a max current of 3.5A. The power adapter is also feeding into a dc-dc step down module which is regulating the current to under-volt a 12V computer case fan, for cooling.
Now, despite burning out the first board for a reason I think i understand, I got the second board to work steadily and without failure. That was, until I turned it off one time.
I had been running the LED for about a half hour (and this was the fifth time ive done so), and then when I was done, i flicked the switch in the circuit to cut the power between the laptop adapter and the rest of the equipment, and this is when I noticed that the powder adapter's LED light was flickering, as it had done when the last board burned out and was shorting. Realizing what was about to happen, i went to pull the plug, but I was too slow and the second board burnt out.
The component that is burning out is the NCE6075K N-Channel Enhancement MOSFET (DATASHEET), and I don't know enough about electronics to figure out why exactly.
I find it very strange in my mind that the board only burnt out after the switch was turned off (and i think the switch is working fine, it had been up until then).
I need to figure out what the problem is so that I can avoid it with the replacement boards.... I figure maybe the capacitors in the system are discharging through the MOSFET after the switch is turned off, but I don't know enough about electronics to know if this is an issue.
Unfortunately, I can't provide a circuit diagram for the boosting boards because I can't seem to find one anywhere on the internet. Instead, please take this crudely-drawn illustration of the basic circuit.
Any help is greatly appreciated, thank you.
I'm trying to build a photography light and I've been running into an issue with my DC-DC boost converters burning out for a reason I can't identify.
The circuit is pretty simple: A 120W AC-DC power adapter is outputting 12V to the boost converter (LINK), which is bumping it up to 32V, with a constant-current limit of 3A. The boost converter is then outputting to a 100W LED chip rated for a forward voltage of 30-34V and a max current of 3.5A. The power adapter is also feeding into a dc-dc step down module which is regulating the current to under-volt a 12V computer case fan, for cooling.
Now, despite burning out the first board for a reason I think i understand, I got the second board to work steadily and without failure. That was, until I turned it off one time.
I had been running the LED for about a half hour (and this was the fifth time ive done so), and then when I was done, i flicked the switch in the circuit to cut the power between the laptop adapter and the rest of the equipment, and this is when I noticed that the powder adapter's LED light was flickering, as it had done when the last board burned out and was shorting. Realizing what was about to happen, i went to pull the plug, but I was too slow and the second board burnt out.
The component that is burning out is the NCE6075K N-Channel Enhancement MOSFET (DATASHEET), and I don't know enough about electronics to figure out why exactly.
I find it very strange in my mind that the board only burnt out after the switch was turned off (and i think the switch is working fine, it had been up until then).
I need to figure out what the problem is so that I can avoid it with the replacement boards.... I figure maybe the capacitors in the system are discharging through the MOSFET after the switch is turned off, but I don't know enough about electronics to know if this is an issue.
Unfortunately, I can't provide a circuit diagram for the boosting boards because I can't seem to find one anywhere on the internet. Instead, please take this crudely-drawn illustration of the basic circuit.
Any help is greatly appreciated, thank you.