The Black Box circuit                                                                    Return to The upgraded circuit

Components

 

 

R1    1k C1   100uf
R2    100k C2    10uf
R3    200k IC1    NE555C
R4    220k Q1     PNP Small signal transistor
R5    1k Q2    NPN Medium power transistor
Sensor   Reed switch and Enamelled wire

 

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