Editing Comparator (section)

===Relaxation oscillator===
A comparator can be used to build a [[relaxation oscillator]]. It uses both positive and negative feedback. The positive feedback is a [[Schmitt trigger]] configuration. Alone, the trigger is a [[bistable multivibrator]]. However, the slow [[negative feedback]] added to the trigger by the RC circuit causes the circuit to oscillate automatically. That is, the addition of the RC circuit turns the hysteretic bistable [[multivibrator]] into an [[astable multivibrator]].<ref>{{cite book |author1=Paul Horowitz |author2=Winfield Hill |title=The Art of Electronics |publisher=Cambridge University Press |edition=2nd |place=Cambridge |year=1989 |pages=284–285}}</ref>