What kind of hazard might exist in a power supply when it is turned off and disconnected?

What kind of hazard might exist in a power supply when it is turned off and disconnected?

• A. Static electricity could damage the grounding system
• B. Circulating currents inside the transformer might cause damage
• C. The fuse might blow if you remove the cover
• D. You might receive an electric shock from stored charge in large capacitors

Answer: (D)

When a power supply is turned off and disconnected, there is still a significant hazard associated with the stored charge in large capacitors. Even after disconnection from AC power, these capacitors can retain a potentially harmful amount of electrical energy. If you were to touch the terminals of a charged capacitor, it could result in an electric shock, which may cause injury. This is particularly important in power supplies used for radio and other electronic equipment where large capacitors are common for smoothing out voltage fluctuations. Understanding how to safely discharge these capacitors before servicing or handling a power supply is essential for preventing electric shock hazards. Proper techniques include using a resistor to discharge the capacitor safely or utilizing a discharge tool designed for this purpose before working on the equipment.

When a power supply is turned off and disconnected, there is still a significant hazard associated with the stored charge in large capacitors. Even after disconnection from AC power, these capacitors can retain a potentially harmful amount of electrical energy. If you were to touch the terminals of a charged capacitor, it could result in an electric shock, which may cause injury.

This is particularly important in power supplies used for radio and other electronic equipment where large capacitors are common for smoothing out voltage fluctuations. Understanding how to safely discharge these capacitors before servicing or handling a power supply is essential for preventing electric shock hazards. Proper techniques include using a resistor to discharge the capacitor safely or utilizing a discharge tool designed for this purpose before working on the equipment.