I have seen them too. About ten years ago an old friend came up with a near substitute. To make the light go on and off, he used a condensor from a large electric motor with battery power also. The condensor would load up over about 1/2 to 1 second and then the light would softly come on, blink and be off until the condensor loaded up a second later.

Thus the big problem is handling the large condensor. He just got his from an old washing machine motor. These things are not small and thus may not be suitable for your effort.


Wm.