Voltage threshold alarm trigger
858 views · Published 3 July 2012 · 0:51 · Indexed 11 October 2026
Channel: Paul Nathan · 2012 · Education
How to activate an alarm based on an input voltage exceeding a preset threshold (here set to 8V). This circuit comprises an LM317 voltage regulator for maintaining a stable reference, an open-loop Op-amp LM358 to act as a basic comparator that switches on a transistor to power a load, in this case a red LED and a buzzer.
