Abstract: A power line filter suppresses or dissipates and clamps short rise time high voltage transients carried by power transmission lines. 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. The module used with a direct current power line includes a capacitor, a selenium surge suppressor and a metal oxide varistor connected in parallel. The module used with an alternating current power line includes a capacitor, a selenium surge suppressor and a gas tube connected in parallel. The module used with the alternating current power line can also include a metal oxide varistor also connected in parallel. The alternating current power line filter modules can be connected to single phase, two-phase or three-phase wye and delta power systems.