Two wire 4-20mA isolator

A two-wire 4-20mA isolator refers to an electronic device that can operate in a circuit without the need for a power supply when there is a signal. Devices that can operate without a power supply are usually referred to as passive components. The commonly used passive components in circuits are diodes, resistors, inductors, and capacitors. Devices in circuits that require an external auxiliary power supply to function properly are called active devices. Active devices are generally used to isolate, amplify, convert, and transmit signals.