Christmas Circuit Collection

compilation of circuits for the odd ‘learn-while-u-tinker’ hour you should be able to claim for yourself this December. Most of the parts used in the projects we reckon may be in your junkbox or hidden in a drawer.
Subjects: Bat detector – Back door alarm – Poltergeist – Power cut alert – Mini radio gives maxi sound – Nostalgic tube sound from an IC – A higher note… – Poor man’s metal detector – Efficient camping dimmer – Touchless switch.