electronic coil with ferrite core and blue small color coded resistors on red copper wire

amplifier background band blue blur board bokeh cable carbon circuit closeup code coil color component conductor copper core cylinder detail device disposal educative electrical electromagnet electromagnetic electronic electrotechnics electrotechnology element engineering ewaste ferrite ferromagnetic field frequency green inductance induction inductor industry inside laboratory macro magnetic material miniature nobody nopeople passive pcb power radio red repair research resistor science service shiny signal small soldered solenoid spiral technical technology transmission twisted voltage winding wire wrapped