Great video, I fixed a 12v adapter and then tried to modify it to have a variable output voltage by replacing the 2 ref resistors with a 10k pot, I didn't bother with using a lamp in series which is a BIG MISTAKE, When I first plugged it in the output was fluctuating like crazy, I tried to adjust the pot and when I reached one of the pot limits I experienced an ElectroBOOM moment, fuse blown and now I have an adapter that somehow is now shorted on both the output & the input side xD
I was surprised to see such little voltage drop across the 24-26 gauge Ethernet cable you salvaged. lol. Thanks for the video...glad to know there may be more to this than just tweaking the voltage reference. Although, it may be less involved as I intend on lowering the voltage output instead of increasing.
Yeah, those Ethernet wires must be decent copper, although this is also pretty low current. The main downside of those wires are that the insulation has a pretty low melt point. I think lowering the voltage on an smps is probably going to be safer generally, especially if you don't pull more output current. I think if the voltage is lowered too much, and the switcher chip is already running at a low duty cycle, and can't run any slower, you could run into problems though.
@@Datzfunk I've considered that the duty cycle might be an issue. I guess I'll see what happens, but I'm only turning it down to 22-23V from 24V. I'm not about to start rewinding the transformer, that's for sure.
Great video, I fixed a 12v adapter and then tried to modify it to have a variable output voltage by replacing the 2 ref resistors with a 10k pot, I didn't bother with using a lamp in series which is a BIG MISTAKE, When I first plugged it in the output was fluctuating like crazy, I tried to adjust the pot and when I reached one of the pot limits I experienced an ElectroBOOM moment, fuse blown and now I have an adapter that somehow is now shorted on both the output & the input side xD
I was surprised to see such little voltage drop across the 24-26 gauge Ethernet cable you salvaged. lol.
Thanks for the video...glad to know there may be more to this than just tweaking the voltage reference. Although, it may be less involved as I intend on lowering the voltage output instead of increasing.
Yeah, those Ethernet wires must be decent copper, although this is also pretty low current. The main downside of those wires are that the insulation has a pretty low melt point. I think lowering the voltage on an smps is probably going to be safer generally, especially if you don't pull more output current. I think if the voltage is lowered too much, and the switcher chip is already running at a low duty cycle, and can't run any slower, you could run into problems though.
@@Datzfunk I've considered that the duty cycle might be an issue. I guess I'll see what happens, but I'm only turning it down to 22-23V from 24V.
I'm not about to start rewinding the transformer, that's for sure.