For quite some time I've been trying to figure out the proper circuit to use. I have been designing a flash grenade for airsoft, its just leds and a siren in a small shell. I have been trying to make a circuit that has a delay power on and only stays on for about 5 seconds. Im using a 9volt battery to power everything. I just need someone to help me with the circuit. Im fairly new to this so please any help is appreciated.