Hello,
The question is below if you want to skip the background.
Background:
I built a make-shift power supply that I use for a vaping box mod while I'm sitting at my desk so I don't have to worry about charging batteries etc. The way I did it was quite simple... I used a decent sized transformer (because this is a fairly high wattage application). So the voltage is stepped down to roughly 30 volts AC. From there, I feed a packaged bridge rectifier which then gives me roughly the same voltage DC. THEN, I connect the DC output of the rectifier to a gizmo that I bought from Amazon for $12 (rated at 15 amps at 24 volts DC), that allows me to step down DC anywhere from like 2 volts to something like 95% of the input voltage. So I step the voltage down to 6 Volts DC and feed that to my Vape mod.
Question:
When I put my Fluke in line with the 6 volts and check the current as I'm using the vape, I read 12.2 amps, which is 73.2 watts.
THEN, I read the current on the AC side from the wall to the transformer (which is of course 120 volts AC) and the amperage being drawn from the wall is 1.8 amps while i'm running the vape, which comes out to 216 watts (yes, I did make sure the Fluke was dialed on AC not DC ).
216 - 73.2 = 142.8 watts MISSING...
...to me, this means that I'm losing 142.8 watts in the transformer, the rectifier and the voltage step down device, but this is more than double the wattage that I need for the vape ... is it possible that these components are really that inefficient? Or is my math wrong somewhere?
It's been many years since I took electronics, and I'm trying to understand what I'm seeing, so hopefully someone much more in the know than I am can help me make sense of this.
Thank you,
Mike
The question is below if you want to skip the background.
Background:
I built a make-shift power supply that I use for a vaping box mod while I'm sitting at my desk so I don't have to worry about charging batteries etc. The way I did it was quite simple... I used a decent sized transformer (because this is a fairly high wattage application). So the voltage is stepped down to roughly 30 volts AC. From there, I feed a packaged bridge rectifier which then gives me roughly the same voltage DC. THEN, I connect the DC output of the rectifier to a gizmo that I bought from Amazon for $12 (rated at 15 amps at 24 volts DC), that allows me to step down DC anywhere from like 2 volts to something like 95% of the input voltage. So I step the voltage down to 6 Volts DC and feed that to my Vape mod.
Question:
When I put my Fluke in line with the 6 volts and check the current as I'm using the vape, I read 12.2 amps, which is 73.2 watts.
THEN, I read the current on the AC side from the wall to the transformer (which is of course 120 volts AC) and the amperage being drawn from the wall is 1.8 amps while i'm running the vape, which comes out to 216 watts (yes, I did make sure the Fluke was dialed on AC not DC ).
216 - 73.2 = 142.8 watts MISSING...
...to me, this means that I'm losing 142.8 watts in the transformer, the rectifier and the voltage step down device, but this is more than double the wattage that I need for the vape ... is it possible that these components are really that inefficient? Or is my math wrong somewhere?
It's been many years since I took electronics, and I'm trying to understand what I'm seeing, so hopefully someone much more in the know than I am can help me make sense of this.
Thank you,
Mike
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