This constructor allows you to assemble a small and effective device - an alarm simulator, the only task of which is to periodically turn on the LED as in real security systems. This may be enough to scare away a potential thief if for some reason you cannot install a full-fledged security alarm. Also, the device may be interesting for gaming and educational purposes.

A feature is the ability to power both from an external source and from a 9 volt battery. When the main power fails, the switchover to the battery will occur automatically. Because to the use of a low-power version of the 555 timer, the device can continuously work up to 1 month from a single battery. 

When buying, you will receive a set of electronic components for self-assembly.

There is no battery in the constructor.