Ebay DPS Power supply module current draw?
Good day folks. Some of you may know that a while back I got myself one of those power supply modules you see on banggood, aliexpress and just about any other online shopping website. I powered the thing off a UPS transformer and I'm very pleased with the results...built a nice oversized enclosure for it and it's running quite happily. Today I wanted to test its limits a bit, to see what it can put out, so I took a wrench and shorted the output terminals together and raised the voltage to 1v. It went into constant current mode immediately, since even at 1v it would've exceeded the maximum 15A it's designed to carry - after all, the resistance of the wrench was extremely low, it's a solid piece of steel (or whatever it's made out of 
). The display showed 15A indeed, at about half volt, so roughly 6-7w total.
This is when I noticed something strange: I took my clamp meter and wrapped it around one of the wires coming from the bridge rectifier into the input of the PSU module and it only showed 3A, even though the display said 15...:| What is going on ? Is this a SMPS and the input current doesn't match the load current, or am I completely oblivious to something ? I'm pretty sure there's no way you can draw 15a on one side and only 3a on the other.....or is there ? I think we're talking about a SMPS...what do you guys think ?
). The display showed 15A indeed, at about half volt, so roughly 6-7w total.This is when I noticed something strange: I took my clamp meter and wrapped it around one of the wires coming from the bridge rectifier into the input of the PSU module and it only showed 3A, even though the display said 15...:| What is going on ? Is this a SMPS and the input current doesn't match the load current, or am I completely oblivious to something ? I'm pretty sure there's no way you can draw 15a on one side and only 3a on the other.....or is there ? I think we're talking about a SMPS...what do you guys think ?
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