3 wire proximity switch help

[mikem]

cropwell
I ran the brown + wire to the positive on the 12v transformer. Then I ran the blue - to the Ground on the 12v transformer and the BOB gnd then I put the black on the input signal and the switch lit up but wouldn't trigger. So I disconnected the blue just from the transformer to the BOB and it now works like it should. It's more sensitive and works great.

So no transistors.

Thanks Mike