Whadda complete load of s***

I’ve just had a WPM402 module delivered. It is meant to take between 3.5V and 35V and boost it to between 5V and 55V. I’m looking to use it to boost 18V up to 36V, so well within spec.

I stick 18V on it, an LED turns on, I go to get a trimmer to adjust the output voltage with the trim pot, when I look back the LED is out, odd I thought, perhaps it just lights up when the module is turned on. Anyway, I stick a meter on the output so I can see what I’m doing… 18V, ok fine, so I turn the pot… nothing, many turns either way… nothing, stuck at 18V. I turn the input down to 5V, output drops to 5V and there’s no adjustment there either.

The LM2577 chip did get hot, not mega hot, but pretty hot, too hot I’d say, considering I hadn’t put a load on the module yet. The whole thing also draws 250mA, which strikes me as a hell of a lot, especially at 18V. So was the thing faulty, will another fail if I buy another one and treat it the same? What am I missing here? It appears either the specs and instructions are completely wrong, or the module is faulty. Either way I’m not happy, especially as there seems to be no way to email Whadda on their website, so I came on here to spread the bad new publicly instead and shout and kick my arms and legs about as hard as I can.

Hi @blablabla

Did you read the specs?
Speciall this!
please ensure that the output voltage higher than the input voltage, so as not to damage the module!!!

Kind regards,