PaulWood

I see. Thanks for the explanation regarding suffix and how the letter can be used as a decimal point. Looks like the resistors should then be: R1 = 10k R2 = 1M R3 = 82 R4 = 1M R5 = 100k R6 = 1M R7 = 220 Tolerance is unimportant as is power (1/4watt should be OK). Capacitors: While looking at capacitors (on digikey.com) I see a plethora of options. Is is OK to utilize general purpose, ceramic, tolerance +80%/-20%, 50VDC? Make sure I get units correct: 1

Thanks. I might actually be learning something! Sorry, but I don't see any change to the resistor values from the previous drawing: R1 = 10k R2 = 1M R3 = 82 R4 = 1M R5 = 100k R6 = 1M R7 = 220k

Thanks for the clarifications. I understand your point about not showing the pin numbers on schematics. I just needed something to translate the schematic into something more visual that would in some way show me how the connections between the parts and the pins could flow. That's why I showed the IC as a box, even though that's not the correct way to show it. What tolerance and wattage should I use for the various resistors? You mentioned that two of the resistors were wrong. Do you mean the missing "k" label or were the values wrong?

Hero999, I looked long and hard at the "Low power IR gate flash" drawing you provided the other day. Didn't make a whole lot of sense to me so I attempted to translate your drawing into one that includes the 74HC14 pin out. Please take a look at the attached and let me know if I even came close. Thanks. Low_power_IR_gate_flash_#1.pdf

Hero999, You've been so kind to work on my project, even to provide a potential solution schematic. As mentioned above, I have no electronics background and it is apparent to me that the IR-switched solution I was envisioning is beyond my abilities. In my ignorance, I don't understand what your schematic is doing - much less am able to put the pieces together. I googled the two parts listed to find out what they are; however, it's still "Greek to me". I think if I were set on pursuing this project I would need someone to develop a turn-key solution that I could connect to a power source and signal LED. I imaging that would be cost prohibitive for such a trivial project. Now, if I were developing a solution to mass production, that would be another story. Again, thanks for all your effort.

On second thought, what if I use the original circuit design with either 2xAA or 2xC Nicad batteries and incorporate a simple solar battery charger?

I understand about the C vs AA battery. I was thinking along those lines also. I understand the concept you laid out regarding changes to the circuit to reduce the current draw and reducing the duty cycle of both the flashing LED and the emitter. However, I haven't the foggiest idea how to go about doing that. I think I'm getting in way over my head for this project. After all, it is rather trivial: I got tired of going out to the street on a cold snowy morning to fetch the newspaper only to find out it hadn't been delivered yet. So I started thinking about a signaling device. The first generation I built used a couple of mini-switches, 2-AA batteries and one red blinking LED. Worked find and the battery lasted several months. Only problem I had was selecting the mini-switches and positioning them such that the weight of the paper would close one or more switch. Sometimes with a light paper, none of the switches would close. Recently the snow plow destroyed my mail box and newspaper box, so I thought I would try a IR circuit as a sensor that would not be dependent upon the weight of the paper. So, that's what brought me to this forum (I'm a pharmacist so I have no real electronic background). I appreciate your information, patience and understanding; but, I think I'll need to abandon this project and rebuild a mini-switch based signal.

Oops. My bad: My original post specified 3-AAA batteries - should be 3-AA batteries.

Hero999, Sorry for the confusion regarding the second circuit - it was actually some junk symbols that I had left on my second Visio page. Didn't realize that it would be a part of the .pdf file. Should have looked more carefully. I deleted the second circuit and now the .pdf file should be OK. And also, thanks again for pointing out my backward emitter and detector in the original first circuit. I'll pursue your resistor recommendations. Any thoughts about battery life with RD = 10k? My hope was to have a set of batteries last a couple of months, but I'm wondering if that's really possible.

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.

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-AAA-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. Edit: Should be 3-AA not 3-AAA batteries. IR-Blinker_Circuit.pdf