Charger D ripple

Mobile charger has become one of the most popular accessories/consumables for smart-phone (thanks to Apple’s non-removable battery design). Being a heavy mobile internet user, I have accumulated several mobile chargers, ranging from top-of-the-line Energizer “Energi To Go”series, to homebrew single 18650 lithium battery adaptor. All of them have proved to charge mobile phone well. But are they good enough to power testing circuits for lab use? I cannot have good confidence until I tear them apart and measure their performances. Continue reading