為確保符合所有國際標準，電信應用隔離電源的設計人員需要考慮以下因素：輸入電壓絕不是主電源的 110V 或 220V，而是鉛酸電池的較低電壓（-12V、-24V 或 -48V），通過整流由主電源充電（圖 1）。（如果主電源發生故障，電池將為電信系統提供備用電源。）為防止離子流引起的腐蝕，輸入電壓始終為負，正極接地。圖 1。在此電信系統中使用的備用架構框圖中，電池塊由主電源整流器保持充電狀態。如果主電源發生故障，電池塊將為系統供電，以防止傳輸中斷。

To ensure compliance with all international standards, the designer of an isolated power supply for telecom applications needs to take certain facts into account: The input voltage is never 110V or 220V from the mains, but the lower voltage of a lead-acid battery (-12V, -24V, or -48V) that is charged by means of the mains through rectification (Figure 1). (Batteries back up the telecom system in case of failure in the mains supply.) To combat corrosion due to ion flow, the input voltage is always negative, with the positive terminal connected to ground.

Figure 1. In this block diagram of the backup architecture used in telecom systems, a battery block is kept charged by the mains rectifier. In the event of a mains failure, it supplies the system to prevent transmission interruptions.