Rudimentary Circuit to Eliminate Glitches/Bounces on a Signal Hardware: Multifunction DAQ (MIO)>>M Series>>PCI-6233
Problem: I have a shaft rotator that is rotating two magnets. Once the magnet passes a point on the rotator, it closes the switch to my analog input device. However, I am seeing glitches on my signal once the circuit is closed. How can I eliminate these glitches? Solution: Mechanical switches usually do not open or close cleanly. When the switch opens or closes, it makes and breaks contact several times before settling to its final position. This is called “bouncing” and is what is causing the spikes on your analog input graph. To reduce bouncing on a circuit, a rudimentary RC circuit can be constructed as shown in the following diagram. Make sure that the resistor and capacitor values are chosen such that the RC time constant is larger than the bounce time.  Rudimentary Switch Debouncing Circuit Related Links: Attachments:  - RC_debounce.gif
Report Date: 12/15/2006 Last Updated: 12/18/2006 Document ID: 44EE4N0L |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
