This is what I removed from my Cessna yesterday
On the right you see the beacon which is a simple 28V 150W light bulb in a red glass enclosure. The massive box on the left side is the "electronics" to make it blink. It has two outputs which it alternates. Now the interesting part. If it was just the lamp and the circuit, the electrical system would constantly get a 5.3A consumer turned on and off. This would make the amp meter needle fluctuate and show the blinking. Obviously Cessna didn't want that. So they've come up with an amazing solution: they installed a gigantic resistor (in the front) in an area with good cooling (near the elevator) and the circuit alternates the 150W between the lamp and the resistor.
I have to admit, I very much prefer my new LED beacon 
I take it, you've redone your W&B sheets ;-))
That's hilarious. I can see the reasoning behind it... but still hilarious.
The obvious alternative is to replace the resistor by a second lamp.
Couldn't help thinking of some national implementations:
-) German: according to rules, red one side, green the other
-) Italian: same but with a white one in between to form their flag - plus perhaps some ingeneous way to make that one flash too
-) Irish: two reds adjacent
A second red one on the underside... then dream that you have landed the elusive first RHS job on a B737?
:)
On a sidenote: the photograph shows on the left side a male and female three-pole connector, am I right this is the type called "Molex connector" ? It seems to me they exist in an endless variety of configurations, especially as the "inner counterpiece" can be either square or round for each individual pin..? Or does there exist some standardisation?
Molex make a million different configurations of these cheap and dirty plastic connectors, which were largely abandoned in motor vehicles (well, "quality" ones, anyway) about 20 years ago because they were crap and were responsible for a large % of vehicle breakdowns. The car industry uses similar connectors but with o-rings to (more or less) seal them from water ingress.
But aviation continues to use them, even on $500k planes.
I wouldn't use them on a lawn mower. And I make sure no wiring in my plane uses these things.
That 150W resistor is just a tragic example of the "competence" of the designers of these things. It's a bit like the huge "dropper" resistor which was used in TVs, back in the old days when all the valve heaters were connected in series and connected right across the mains supply, and a massive resistor was used to drop the remaining voltage.
am I right this is the type called "Molex connector"
I am not sure what they are called, but they were used in PC's up until more recent SATA kind of drives to provide power to disks and CD-ROM's.
