IR Switch for LED

[PaulWood]

I am a real neophyte at this, so please excuse my ignorance.

I am trying to design a circuit to turn on a blinking LED when an IR Emitter-Detector beam is broken. The distance between the Emitter and Detector will be approximately 6 inches. It will be located such that shaded daylight will fall on them. The circuit I designed (Microsoft Visio) with parts specifications is attached. I would appreciate any comments regarding the circuit and/or its components.

Specifically, I would like someone who is much more knowledgeable regarding the math to validate, or correct, the resistor values I have.
Further, any thoughts on the life of the 3-AA battery pack that I propose to use. I think the IR Emitter-Detector will continuously draw some amount of current.

Thanks for the help and your insight.

 

[ronv]

It looks like the detector is upside down.
Running the emitter at maximum power is maybe to high - seems like a 56 ohm 1/4 watt resistor would run it at about 50 ma. This would help the battery life.
You may need to experiment with Rd or make it adjustable.
Here is a link with some ideas on shielding and circuits.

**broken link removed**

Alkaline AAA have 1200 ma hour ratings so you might get 20 hours from a set. How much were you looking for?

 

[PaulWood]

Yup. I must have been standing on my head when I drew the circuit. I edited it and I think it's drawn correctly now.

ronv: Thanks for the link. I was hoping to get months of use from one set of batteries. Maybe that's impossible.