555 timer: A widely used circuit that can run in either of two modes: monostable and astable. In monostable, it can produce accurate time delays, and in astable it can produce rectangular waves with a variable duty cycle. Related posts: Personnel Management Operative Functions Administrative Role of PM Competency HR Management Role Change Personnel Policies Personnel Procedures Appealed Policies Implied Policies Specific Policies Personnel records Research Pure research Personnel research Attitude or Opinion Survey Turnover Secondary research Applied research Personnel audit Read more articles Previous PostField-effect Transistor Next PostFlag