Isolated 4 20ma Receiver Circuit

The 4 20 ma current loop is the prevailing process control signal in many industries.

Isolated 4 20ma receiver circuit.

It is an ideal method of transferring process information because current does not change as it travels from transmitter to receiver. 4 20 ma current loops overview. Description the rcv420 is a precision current loop receiver de signed to convert a 4 20ma input signal into a 0 5v output signal. 2 isolated transmitter and non isolated receiver current loop fig.

Unlike voltage current does not vary due to line resistance or capacitance both which change with cable length. It is also much simpler and cost effective. 3 non isolated transmitter and isolated receiver figures 4 and 5 show the transmitter transfer function. An iso122 low cost isolation amplifier isolates the 0 5v signal.

The loop current il is the product of the sensor voltage vin times the transmitter trans conductance milli siemens. A loop powered 4 20ma sensor transmitter is the most cost effective and desirable solution that allows receiving the power and transmitting the data over a 2 wire 4 20ma current loop. Ignaciof on jul 21 2016. Fully isolated 4 wire the transmitter and control panel use separate power supplies.

Back then if i needed to convert current to voltage i d use any solution based integrated circuit ic to get the job done quickly. Power 15v for the. 0 emman a on aug 1 2016. However if a sensor itself consumes more than 3 4ma of 4 20ma loop budget then it requires an additional power source not combined with the 4 20ma.

Before i started setting up my small contract manufacturing business i was a pure electronics designer. An xtr101 converts a position sensor output into a two wire 4 20ma current loop signal. 4 20ma current loop products current loops are useful for accurately communicating analog signals over long distances. Simple and effective 4 20ma current loop receiver with minimal components.

As a monolithic circuit it offers high reliability at low cost. The receiver in figure 4 has a trans. The 4 20ma signal flows through two separate cable cores between the transmitter and control panel. The circuit consists of a pre mium grade operational amplifier an on chip precision.

I am using a ad627 for my 4 20ma receiver now i want to add an analog isolation amplifier my circuit has a 5vdc simple power suply wich ic do you will use for this. 3 easy cost effective field repair of a precision circuit.