Hello!
Given: A lot of fuses that protects some power electronics (transformers, incandescent lamps, relays). Sometimes a fuse blows and it needs to be spotted and replaced. But it is very hard to carefully look through a lots of fuses and inspect each thin melting wire. So I need some indication device of a blown fuse that connects to fuse itself.
This indication device needs to be:
1. Simple
2. Small
3. Working on AC/DC 12..220V ranges.
My first thought was "Hey, let's just choose a proper resistor!":
But in order to LED be nearly visible on 12V in case of 220V resistor will dissipate a lot of heat, so it needs to be huge.
Well... let's add power-limiting capacitor!:
But in this case indicator looses an ability to work on DC voltages.
Now I am thinking of using resistor + blinking leds with ICs inside them to reduce current consumption and thus a power dissipation on resistor. Most of blinking leds have a 50% duty cycle and there is not much of power saving. I am trying to find SMD blinking led with duty cycle of about 10% (100 msec on, 1 sec off) but still no success with that.
1. Any advices of how to find leds with small duty cycle will be appreciated (maybe they are not existing at all?).
2. Perhaps I am missing another ways to make simple blown-fuse indication...
Thanks =)