I'm trying to design part of a circuit that will tally a score based on IR sensors - multiple holes that will each have their own sensor set. I'm using an IR LED as my source and an IR phototransistor as my receiver, 74LS190D as my counter and 74LS48D to convert to a seven segment display. I have some questions:

1) 74190 clock input is triggered by a LO to HI signal. How should I convert my IR signal, which will switch from HI-LO when blocked?
2) How can I change the count value for each sensor? Obviously, one broken beam equals one count, but each hole should have a different point value assigned to it.
3) How do I then sum all those points from the holes into one clock input for the counter?

Any tips about what parts to look into would be much appreciated. Or maybe I'm approaching this problem in the wrong way. I'm a total beginner haha.

 

hi SC,
For each hole, AC couple its output to a multi input OR Gate, then use the output from the OR to clock the counter.
E

 

Thanks! I used that and I ended up using two 555s per hole to create more pulses so that each hole could be worth more points as suggested here.

I'm trying to design part of a circuit in which I need to count how long an IR sensor is blocked. I'm using a IR LED and a phototransistor as the receiver. When the beam is broken for less than 3 seconds, I want a LED to light up for 1 second and when the beam is broken for more than 3 seconds, I want a LED to light up for 3 seconds. I have the circuits for the LEDs by using 555 timers, but can't figure out how to count how long the IR beam is blocked.