Infrared Sensor Help

[Sanglant]

I am trying to build a circuit that uses an infrared sensor to trigger a digital counting circuit. The problem that I am having is that when the path of the beam gets blocked, the circuit triggers too many times. I am guessing this is caused by some sort of bounce from the beam (I am using a reflector beam). I am trying to figure out what I can do to eliminate the bounce and have the circuit only clock one pulse instead of the 50 or so it clocks each time the beam is broken. I am using a 7490 bcd counter to drive a 7447 decoder.

 

[TBennettcc]

Check this out, and then see if you have any more questions:

http://lmgtfy.com/?q=debounce+circuit

 

[(*steve*)]

I would seriously consider any solution that uses the term "monostable".

edit: since you're using 74 series TTL, look at the datasheets for the 74121 / 74122 / 74123.