I'm currently finishing my GCSE engineering project and I am attempting to use a dual 555 timer circuit as a timer. I am using a schematic I copied off Kitronik Alarm Project Kit, but when simulating and after creating the physical circuit, it has failed to work. I have gone through everything I can think of to no avail.
I have researched how this circuit works, and understand simply how the capacitor charges and drains, but I still have very little understanding of how the circuit is meant to work, and I am having trouble diagnosing problems.
I have used crocodile clips to simulate the circuit, but no combination of reset/trigger switches results in anything changing in my eyes. I have consulted with teachers, but they have not been able to help. Here is an image of the simulated circuit:
Here is the original diagram I copied off, which can be found in this PDF: alarm_project_essentials_2_0
Sorry if I have misused tags