Hello, this is my first post. I am having a problem solving a circuit. The problem is that Im not sure what is happening with the IC chip. I am 75% sure that its some sort of timer chip. Normally, the reed switch is closed and there is no voltage to the piezo siren. When the reed switch opens, the piezo siren emits an oscillating alarm. Oscillation is approx. 3-4 Hz. Any insights as to what is going on with the chip? I have included a drawing of the circuit that I am mostly sure is accurate. If there is some glaring deficiency, please point it out. Having said that, based on the yield of the circuit, does the drawing even look plausible? I did the best I could to make the drawing connections to the chip in the same order as they are on the board. Any ideas?
Circuit diagram:
http://www.flickr.com/photos/dryweave/8427498013/in/photostream/lightbox/
Circuit diagram:
http://www.flickr.com/photos/dryweave/8427498013/in/photostream/lightbox/