An energy-saving switch, also known as a key card switch or hotel room switch, is a device commonly used in hotels to conserve energy when guests are not in their rooms. The primary purpose of this switch is to reduce electricity consumption and promote energy efficiency. Here’s how it typically works:

1. Key Card Activation: When a guest enters their hotel room and inserts their key card (or smart card) into a designated slot or holder near the room’s entrance, the energy-saving switch is activated.
2. Room Power Activation: Once the key card is inserted, it completes an electrical circuit, allowing power to flow to the room’s lighting, HVAC (heating, ventilation, and air conditioning), and other electrical devices.
3. Room Access Control: When the guest leaves the room and removes the key card from the slot, it interrupts the electrical circuit. As a result, power to non-essential devices (e.g., lights, TV, outlets) is automatically turned off.

The key idea behind the energy-saving switch is to ensure that electrical devices in the room are only powered when the guest is present. This helps reduce energy consumption, lowers electricity bills for the hotel, and contributes to environmental sustainability by decreasing energy waste.

In addition to conserving energy, these switches also serve as a security feature. They ensure that guests can’t leave lights or other electrical devices on when they are not in the room.

Please note that the specific design and functionality of energy-saving switches may vary from one hotel to another, but the core concept remains the same: they help save energy by controlling room power based on the presence of the guest’s key card.