Hi all I have been asked to make something to the following criteria
A flashing LED in an environmentally sealed enclosure, visible in total darkness at 200M with a lifetime of 12 months minimum.
All of the electronics and the battery also need to be inside the sealed enclosure, in fact it will probably be potted. There are to be no external switches.
For LED visibility I think I will be using an 8mm LED the problem is how I activate and deactivate it.
I have thought of using a reed switch and activating it by a magnet, the problem is I need to have some type of latch that maintains power as when I remove the magnet the reed switch will open. I then need to disconnect power by operating the same reed switch again but I'm not sure if this is possible.
Any suggestions on the switching circuit and suggestions of the best way to have a bright LED with low current consumption for extended battery life will be appreciated. I am planning to use a PP3 9V battery.
Many Thanks
Phil
A flashing LED in an environmentally sealed enclosure, visible in total darkness at 200M with a lifetime of 12 months minimum.
All of the electronics and the battery also need to be inside the sealed enclosure, in fact it will probably be potted. There are to be no external switches.
For LED visibility I think I will be using an 8mm LED the problem is how I activate and deactivate it.
I have thought of using a reed switch and activating it by a magnet, the problem is I need to have some type of latch that maintains power as when I remove the magnet the reed switch will open. I then need to disconnect power by operating the same reed switch again but I'm not sure if this is possible.
Any suggestions on the switching circuit and suggestions of the best way to have a bright LED with low current consumption for extended battery life will be appreciated. I am planning to use a PP3 9V battery.
Many Thanks
Phil