Chokes - uv-technik international ltd. uv lamps, uv units and uv equipment

If the partial-load choke(s) is (are) replaced by a controllable transductor, the result is a continuously variable ballast. Precise tuning of partial-load choke(s) to the transformer and the desired lamp power is also required here.

(Ballast) Chokes

Low-voltage lamps with a power of up to approx. 5 … 6 kW (in special cases also somewhat higher) can be operated with one or more chokes directly on the mains. The required lamp voltages are as follows: < 160 V for 230 V mains, < 300 V for 400 V mains.

In principle, one choke is sufficient for operating a lamp at a preset power level. The choke limits the lamp current to the desired value. Therefore, the choke must be selected depending on the lamp and on the desired power as well as on the mains voltage and the mains frequency.

By connecting several suitable chokes in parallel (more rarely also in series), a ballast can be switched in different steps to match different lamp power levels. If the choke(s) is (are) replaced by a controllable transductor, this results in a continuously adjustable ballast.

In most cases, a separate ignition unit is required for starting/igniting the lamp.

As chokes are inductive components, they generate an undesired phase shift between mains voltage and mains current which must be compensated by so-called compensation capacitors.

cos phi choke = usually approx. 0.5 … 0.55
cos phi target = approx. 0.9 due to the capacitors