555 integrated circuit from beginning make timer application, call 555 time base circuit again so or 555 timer. Through ceaseless later development, the function is outspread arrived to move light, timing, a variety of domains such as temperature adjustment. Because its are simple, convenient, reliable, be used extensively in all sorts of electron products at present so. Graph of a few kinds of 555 common and classical circuit is below.
Graph 1. 1-100 minute timer circuit
Graph 2. With the DC-AC transformer that 555 circuit comprise
Graph 3. 555 tests circuit