The Patch Component 555 is a timer, full name Universal single-bipolar timer, which combines analog and digital functions in one. Such timers are usually manufactured by bipolar processes, but there are also versions manufactured by CMOS processes. The Patch component 555 offers a wide range of supply voltages, operating from 4.5V to 16V or 3V to 18V, with an output drive current of approximately 200mA and is compatible with TTL, CMOS or analog circuit levels. Due to its low cost and reliable performance, the chip component 555 is widely used in the fields of instrumentation, household appliances, electronic measurement and automatic control. Only a few resistors and capacitors can be connected to realize pulse generation and conversion circuits such as multivibrators, monostable flip-flops and Schmidt flip-flops.