Review on 🔌 DROK USB Cable DC 5V Boost to 9V 12V Step Up Voltage Converter 1A, USB to 9v/12v Step-up Volt Transformer Power Regulator Line with LED Display by Matthew Fadoul

I had high hopes. I really like this brand and have had good luck with other products from them but not this one. I have purchased similar products from several brands and then measured them for voltage and ripple regulation using an electronic load, oscilloscope and voltmeter. This was the worst. With a load of 250 mA, the voltage dropped by about 300 mA. Ripple was around 75mV with an ugly triangular top and square bottom, not even rounded typical waveform (intermittent mode artifacts?) at around 400kHz. The competition was around 1mV rounded PP at 3MHz under a similar load with less than 10mV drop. less than $$$.