The ignition unit on the gas hob. A legacy of it having had cola spilled in it was the circuit board inside the ignitor box arcing across. Cleaned that up but I've never been happy with the way it works: You press the button but only get one spark when you release it. Very simple circuit charges up a capacitor and then the switch dumps that into the spark transformer that has 4 outputs.
What I really want is a stream of sparks all the time the button is pressed. With the addition of a Thyristor and Diac (two kinds of electronic switch) resistor and capacitor it now does just that.
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History is much like an endless waltz: The three beats of war, peace and revolution continue on forever.
However history will change with my coronation - Mariemaia Khushrenada