The MP37CA00 is a Magnetic Pickup consisting of a permanent magnet, a pole-piece and a sensing coil all encapsulated in a cylindrical case. An object (target) of iron, steel or other magnetic material, passing closely by its pole-piece causes distortion of the magnetic flux field passing through the sensing coil and pole piece, which in turn generates a signal voltage. The magnitude of the signal voltage depends on the relative size of the magnetic target, its speed of approach and how close it approaches. The polarity of the signal depends on whether the target is moving toward or away from the pole-piece. Magnetic Pickups are most frequently used to sense passing teeth on a gear, sprocket or timing belt wheel, to bolt-heads, key-ways or other moving machine mounted targets. The device features in-line preamplifier, simple, reliable & economical pulse generators for speed switches digital tachometers frequency to DC converters.