What transistor to use?

Congratulations! I'm looking forward to that myself. Sadly my job isn't nearly as interesting or mentally challenging as yours. I'm a mental health therapist

I'm sure they must have a website, it's a company that I think makes electronics for law enforcement, Rockwell Collins or some such. Of course we're getting it second hand from the sheriff's department.

I will definitely take some measurements as soon as I can and will run down the information you've pointed out.

Many thanks!

A lot of people underrate their their jobs and talents. Although being a a design engineer may sound very interesting, as the saying goes, its 99% perspiration and 1% inspiration and, as you move up the management tree, even the 1% disappears.

One day I was sitting in my office doing another long document that no one would read and I thought to hell with this. After checking my pension was OK, I gave notice there and then. Instead of having to work three months notice I was free in a month.

Sometimes I dream that I am at a meaningless meeting or that that I have to be up at six in the morning to drive to work, only to wake and realise that it had only been a dream.

About three years after I left (not because of) the management finally excelled themselves and closed the site- a sad end to a once great division.

Now I have a free hand and have done many of the things that I had always planned to do.

spec

It was said that the receiver is powered from one AG3 battery cell. It has a capacity of only 35mAh because it is a tiny button alkaline cell. Its load is usually only 0.083mA. I doubt that the receiver current is that low.
It was said that the LED is a "leading light" so I guess it is up high and guides the rescuers to its location. It is IR and it flashes. I doubt that it uses a current as high as 9-10A.
Does the receiver cause it to flash or is a flashing circuit needed?