Debouncing thumb|right|SPST switch bounce filter using a Schmitt trigger and capacitor The effects of contact bounce can be eliminated by: Use of mercury-wetted contacts, but these are now infrequently used because of the hazards of mercury. Alternatively, contact circuit voltages can be low-pass filtered to reduce or eliminate multiple pulses from appearing. In digital systems, multiple samples of the contact state can be taken at a low rate and examined for a steady sequence, so that contacts can settle before the contact level is considered reliable and acted upon. See . Bounce in SPDT ("single-pole, double-throw") switch contacts signals can be filtered out using an SR flip-flop (latch) or Schmitt trigger. All of these methods are referred to as 'debouncing'.
debouncing thumb|right|spst switch bounce filter using a schmitt trigger and capacitor the effects of contact bounce can be eliminated by use of mercury-wetted contacts but these are now infrequently used because of the hazards of mercury alternatively contact circuit voltages can be low-pass filtered to reduce or eliminate multiple pulses from appearing in digital systems multiple samples of the contact state can be taken at a low rate and examined for a steady sequence so that contacts can settle before the contact level is considered reliable and acted upon see  bounce in spdt ("single-pole double-throw") switch contacts signals can be filtered out using an sr flip-flop (latch) or schmitt trigger all of these methods are referred to as 'debouncing'