Voltage detectors, also known as voltage testers or non-contact voltage testers, are portable electronic devices used to detect the presence of electric voltage in electrical systems or conductors without making direct contact. They are commonly used by electricians, technicians, and homeowners to identify the presence or absence of voltage in various applications. Here are some key features and functionalities of voltage detectors:

1. Non-Contact Operation: Voltage detectors are designed to detect voltage without the need for physical contact with live conductors. They use proximity or electromagnetic field sensing technology to detect the presence of voltage.

2. Visual and/or Audible Indication: Voltage detectors typically provide visual and/or audible indications to alert the user of voltage presence. They may have LED lights that illuminate or change color, or they may emit beeping sounds to indicate the presence of voltage.

3. Voltage Range: Voltage detectors have a specified voltage range within which they can detect voltage. It is important to choose a voltage detector that matches the voltage range of the application or system being tested.

4. Sensitivity Settings: Some voltage detectors offer adjustable sensitivity settings, allowing the user to set the detection threshold. This can be useful when working with different voltage levels or when trying to pinpoint voltage presence in specific areas.

5. Safety Features: Voltage detectors often have safety features to enhance user safety. These may include insulated probe tips, shock-resistant casings, and built-in self-test functions to ensure the device is functioning correctly.

6. Multi-Purpose Functionality: Many voltage detectors can also detect other electrical phenomena, such as the presence of AC or DC voltage, the presence of a live wire, or the detection of faulty grounding.

7. Battery-Powered: Voltage detectors are typically powered by batteries, making them portable and easy to use in various locations. It is important to ensure the batteries are properly installed and have sufficient power for accurate detection.

Voltage detectors are useful tools for quickly and safely identifying the presence of voltage, helping to prevent electric shock and ensure the safety of electrical work. However, it is important to note that voltage detectors are not designed to provide precise voltage measurements or replace more advanced testing methods. For accurate voltage measurements and detailed electrical testing, other instruments such as multimeters or voltage meters should be used.