Abstract: A power line filter suppresses or dissipates and clamps short rise time high voltage transients carried by power transmission lines and provides continuous protection against continuous type induced noise. The power line filter includes one or more modules connected to either direct current or alternating current power lines to protect sensitive electrical equipment from the transients and continuous noise. The module used with a direct current power line includes a continuous suppressor connected between a source and load, and a selenium surge suppressor and a metal oxide varistor connected in parallel across the source. The module used with an alternating current power line includes a continuous suppressor connected between the source and the load, and a selenium surge suppressor and a gas tube connected in parallel across the source. The module used with the alternating current power line can also include a metal oxide varistor also connected in parallel across the source.