As discussed previously, the actual tattoo foot switch it useful as a button 0b / off. its the same thing as a switch, or electrical conductors. its principles, foot switch consists of two electrical conductors in arrange a meeting so that electricity can flow.
when the footswitch is not on tap, the conductor or iron in it will not stick or meet. then automatically electricity will not flow into the stream.
Vice versa, when you press the footswitch. the electrical conductors will not be met.
example image footswitch ( industry fact ) :
Hand Made or custom :
