Circuit Project Electronic

This is danger beep circuit. It use 555 integrated number circuits build to are a stable mutivibrator that be valuable duty cycle 5% driver loudspeaker 8ohm 0.25W sizes. By change transistor BD136 will get danger beep use make person penetrate a hole is frightened or call for the interest from a neighbor for asks for help. Because of use part a little , then have small-sized and use current just 50mA from a place turns on the power supply 9Volt only.