KY-012 active buzzer module: Wrong wiring diagrams and pinouts

Searching for the KY-012 active piezo buzzer module, you will find a lot of articles on how to connect it with a Raspberry Pi. Unfortunately, some of them are wrong and could in the worst case damage your Raspberry Pi. This article explains why this is the case and what would be a better alternative.

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Replacing the battery in a Philips HQ 7740 Coolskin

The Philips HQ 7740 Coolskin is battery powered shaver. The built-in battery of my Philips HQ 7740 didn't charge properly any longer, so I replaced it. I didn't find instructions on how to change the battery, so this is how I did it...
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