Quote:
Originally Posted by julie_m
I reverse-engineered a Dorman Smith flashing lamp once ..... well, after the battery was spent, what else was there to do with it? I lost the diagram I drew a long time ago; but I do remember it used a strange circuit with an NPN and a PNP transistor, not the flip-flop you might expect. The duty cycle was very low; but I suppose it had to be, given the disposable battery power source and the tunsten filament lamp load.
In case anyone doubts that this behaviour is hereditary, my dad nicked one of the old paraffin ones back in the 1970s ..... while we were on holiday somewhere near Weston-Super-Mare ..... and brought it all the way back up the M5, where it lived in the back garden for years!
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They must have been slow to get the latest stuff down in Zummerset! Students (note the third person in this statement
) were nicking the flashing ones in London by then.
An old paraffin one with a red pygmy bulb in it was strategically placed on the roof of the union building so as to be visible from halls of residence to indicate whether the dramatic society tech workshop was occupied or not.