How much code is in Emergency LED lights? (Emergency exit illuminators)

Hello,

Concerning those LED lights which light up fire exits, they must have a battery so that if the mains fails, the sign is still illuminated by a (reduced) level of light.

Also, every month, these signs must "self test"...that is, they must switch off their own mains, and power the LEDs with the battery for 1 minute, just to show that the battery works..........they can tell if its working by eg measuring the current to the LEDs during this time.

Also, if someone presses a button on the unit, it must go into self-test...i.e., once again, power the LEDs from the battery.

How big would such a code be for such an operation?

I am thinking that surely this must be simple code, worthy of no more than a 10 pin microcontroller at the most?......and a small assembler program?

However, apparently the regulations make the code need to be massive. Is this true?.....and do you know where the regulations can be found for this?

I don't know of any regulations but if I was asked to design such a device, I would think of the simplest microprocessor possible with a comparator which I think is the PIC10F204. It would be more than capable of doing the job and only has 8 pins. With a few extra components to make an external ADC/Comparator a 10F200 would do the job. I would guess maybe 100 lines of asm should be enough code.

Brian.