Technology self-tutoring: the tutor checks the importance of unplugging an unused phone charger. I’ve read in more than one place to unplug a phone charger when it’s not being used. Doing so I find inconvenient, but I’ve done it anyway …

Mobile phones, electronics: should I unplug the phone charger when not in use? Read more »

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The tutor briefly explains the low-pass filter. This explanation draws on ideas from that of a high-pass filter (see my article here). A low-pass filter sends along low frequencies but blocks higher ones. The one we’re looking at today has …

AC Electricity, electronics: how a series low-pass filter works Read more »

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The tutor offers a hint about using the Nexus 4 onboard calculator for sin, cos, and tan. One of my New Year’s resolutions is to get acquainted with my mobile phone. Believe it or not, I’ve been lounging on the …

Mobile phone apps: Nexus 4 onboard calculator: trig functions Read more »

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The tutor explains his recent understanding of a function he’s wondered about. I’ve noticed the ENG function on more than one calculator, but have never used it. I’ve always assumed it means “engineering”; since I’m not one, it makes sense …

Calculator usage: The ENG function on the Casio fx-260solar Read more »

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From time to time, a tutor might get asked questions about electric circuits.  In the context of tutoring or just for general interest, the maximum power transfer theorem  is nice. I last studied electronics about twelve years ago.  Ideas from …

Circuit analysis: The maximum power transfer theorem Read more »

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