rgatlin

I understand about using the 555 timer for different duty cycles, but I am not sure that I can get 2 seconds high, and 45 seconds low. That seems like a really long delay without using astronomical size resistors and cap. ??

New member and I need help bad!! I have a design project for class that requires a circuit to produce a 1kHz tone for 2 seconds, off for 45 seconds, on for 2....and so forth continuously. I need to keep it as simple as possible since we are only allowed to use components that are at the school, i.e. no special IC counters. I pretty much have the 1kHz signal covered with a 555 astable timer but I am having trouble with the 2 second on and 45 second off delay times. Can someone point me in the right direction. I am not sure if I need to drive a counter with another 555 or even how to do that. Any help will be greatly appreciated. ???