Automatic Lights Control

[scarygood536]

What is that?

And mbarazeen, I need a separate count up and Count down signal, I don't think your circuit does that. And Moreever, By seing your explanation [""...and reset when both sensors are unblocked"" ]
I think that you are supposing that Sesor B should be covered before leaving Sensor A (i.e. the sensors should be placed near enough that a person cant fit in between the two (thereby leaving both sensor unblockde)
But in my actual circuit this may not be the case because my sensor produce signal on 'LEAVE' not on 'OBSTRUCT'.

Programmable logic control... Basically you can do everything with less components. All you need is the sensor and make sure you had either AC\dc output card on it depending on what you want to control. And you control everything with logic. For this it would be examine the input(sensor) open and on the output you put an up\down counter(internal to the plc) and the done bit of the counter controls the lights(probably uses a compare statement so the lights stay on when the count is greater than 0). But for a this project it be cooler to actually create it yourself.

 

[mbarazeen]

PLC is easy to work with, but still its not cheaper than 4 ICs of $1 or less each. also its good practice for him to learn basics.