Hello, I have built a small 5W xtmr usinf 3 - 3v cells. When I switch the power on I would like the signal to run 440 ms and then hold for 50 sec. This sequence should continuously repeat itself until the power is turned off. Will a 7555 timer circuit run in a loop or just one time? If so where can I find info on this? If not what should I use?