Weird emergency "open" sign???? (With schematic.)

This is another of those random weird products you occasionally stumble across on eBay. It's a shop-door "OPEN" sign that is based around an emergency light frame that isn't quite compliant with UK safety standards.

It also uses some quirky electronic design features including the use of discrete components (no chips) to keep the price down, and that just makes it a PERFECT teardown item.

Note that the very analogue control circuitry also cuts the battery off at about 0.85V.

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