Helvar L18A 18w Wire Wound Choke

The Helvar L18A 18 W wire‑wound choke is a magnetic ballast using traditional wire‑wound construction, intended for switch‑start operation of 18 W T8 fluorescent lamps. According to Helvar’s legacy documentation, it supports 220 V input and is commonly used in fixtures requiring classic starter‑type control gear.It is a single‑lamp choke (i.e. for one 18 W tube) and is dimensioned to fit within compact luminaire housings.  Because of its magnetic design, it does not feature the advanced protections or features of modern electronic ballasts, but it is valued for simplicity and reliability in certain applications.

From a mechanical standpoint, Helvar lists the model L18A‑L 220 V / 60 Hz as discontinued but retains the specifications: 150 mm length, 28 mm height, 42 mm width, with a 140 mm fixing center spacing. In use, it exhibits the characteristic behaviour of wire‑wound chokes: low maintenance, simplicity, and stable induction operation over a wide range of ambient temperatures. Because it is a switch‑start type, a starter is required in the circuit for proper lamp ignition.  As with all magnetic ballasts, expect slight power losses (magnetics are less efficient than modern electronic ballasts), and ensure proper wiring and clearances in your luminaire design.