This circuit was found in the October 1989 issue of Radio Electronics magazine. It drives an auxiliary relay with the call signal for a possible louder bell.
This circuit is from an old Popular Electronics, but it can be easily implemented nowadays, even...
May 2017 - Torex's XBP14E5UFN, an array of TVS circuit protection diodes with only 0.8 pF of...
This charger circuit provides an initial voltage of 2.5 V and when the current reaches 180 mA the...