Designing a super complex single LED illuminator

Thread Starter


Joined Jan 23, 2016
Hey guys, New to this excellent forum you have here. I feel that this place would be the most ideal place to ask electronics related questions to a project that I have going on.

I will describe what I am trying to do:

I am attempting to design (with your help), single or multiple Infrared LED(s), lit by two AA sized batteries. I wish for this setup to be very bright, very efficient (85% or better) and have constant brightness with varying battery capacity down to 1.6 volts and to produce a single visible "spot" to be able to be picked up by a sensor no less than 15 feet away and at a very wide viewing angle.

My wishes:

1. I wish for a single on/off momentary switch with a small green LED nearby that depicts "On" state. Obviously id like this to consume as little power as possible

2. I wish for a "on time" selection button so that the device automagically powers off after a certain period time of 2, 4, or 6 hours, indicated by 3 low power consuming LED's marked 2, 4, or 6 respectively. Only one LED to be lit at a time. Color could vary but Red preferred.

3. A "Low battery" flashing LED, at about 1 flash for 1 second every 2 seconds, that kicks on at about 25% battery life for two rechargeable NiMh batteries while the device is "on". I'm guessing this is at about 2.2 volts?

4. Automatic shut-off at about 1.6 volts to completely deplete two rechargeable NiMh batteries and fully use their capacity and a cutoff LED that indicates that it is in cutoff mode whitle the power button is pressed.

I also wish to use cheap, off the shelf items that can be readily purchased from basically any electronics shop.

Seems super complicated and a bit over my head, but with your help, I can accomplish this goal. I know only what google can teach me about electronics. I can light a single LED with a resistor no problem. To have it have all the features, that's what I need help with.


Joined Sep 13, 2015
If it very easy to design a super complex anything - anyone can do it.

It is very difficult to design a super simple anything - very few can do it.


Joined Aug 23, 2012
You need to draw a block diagram to show what you want to do and labeling the functions clearly, you also need to make sure which one you want, you can't saying that you want this and want that, you must be make a choice very clearly, otherwise no one could help you.