an important aspect of the invention the detector circuit 10 includes a short conductor or wire 30 that is preferably disposed adjacent to the conductor or other current carrying element at the particular location where pulsed current detection is desired an advantage of the invention is that this pick up wire can be positioned as desired and easily moved as desired to different locations in the ignition circuit the detector 10 can also be realized as a simple add on feature for the overall system and engine rather than needing a specific mounting arrangement as is typical with pulse transformers having cores the wire 30 can simply be laid parallel and adjacent to or twisted with as shown in phantom as at 31 in the drawing the current carrying element of interest or attached thereto by any convenient means such as a suitable adhesive this effectively provides an air gap magnetic coupling between the wire 30 and the current carrying element in the described embodiment the detector 10 simply provides a go no go detection function suitable for example with a diagnostic system not shown therefore precise control of the magnetic coupling is not required thereby allowing the use of an air gap coupling current through the.