PH9185NL Switch Mode Transformers Pulse Electronics PH9185NL Switch Mode Transformers feature reinforced insulation for isolated power supply drivers. These push-pull transformers offer 8mm creepage and 5KVrms isolation (600Vrms continuous). They are UL and TUV certified. Pulse Electronics PH9185NL Switch Mode Transformers are designed for use in applications such as industrial control systems, building automation, smart grids, surveillance, and aeronautics.