Author Archive

Sound level measuring with Android phone

Sound pressure level (SPL) or sound level is a logarithmic measure of the effective sound pressure of a sound relative to a reference value. It is measured in decibels (dB) above a standard reference level (20 µPa, which is usually considered the threshold of human hearing at 1 kHz). I have earlier used several different decibel →

bttn for IoT

Consider the Internet-of-Things (or Internet-of-Everything as some like to call it): everything – yes, literally everything – will be connected. And the IoT sales people have high promises: Cars will be safer. TV will be better. Homes will be smarter. The promise is that different things can talk to each other if you want. Nowadays →

How safe 5V PSU is built

I have posted some teardowns of serveral electronics devices and have some notes on their electrical safety. Examples of ones with questionable safety were this is tiny USB charger and this USB charger. The later USB charger posting has also example of power supply that seems to have properly built safety in it. But how →