Gate Alarm by IC 4011
Monday, November 10th, 2008Figure 1 represents a cheap and simple Gate Alarm, that is intended to run off a small universal AC-DC power supply. C1a is a fast oscillator, and IC1b a slow oscillator, which are combined through IC1c to emit a high pip-pip-pip warning sound when a gate (or window, etc.) is opened. The circuit is intended [...]
