Tag: Current Loop

Chromel Alumel Thermocouple Current Loop Transmitter

The schematic diagram below show signal conditioning circuit for remote current loop temperature transmitter. This thermocouple temperature transmitter is loop powered, means it doesn’t need its own power supply since the supply is provided by the current loop receiver. Thermocouple is basically a junction of two different metallic material that measures the temperature difference. This thermocouple signal conditioner circuit is […]

Read more
Category: Testing and Measurement Tags: , , ,

5V Powered 4-20mA Current Loop Generator

Voltage step-up also employed in figure below, but for a different purpose. The common requirements are transmission of industry standard 4-20mA current loop signals to valves and other actuators.   Current transmitters is required by resistive line losses and actuator impedance to be able to force a compliance voltage of at least 20V. 5V powered systems usually cannot meet current […]

Read more
Category: Control and Monitoring Tags:

OP90 4 mA to 20 mA Current Loop Transmitter

An output of 4 mA to 20 mA that is linearly proportional to the input voltage is provided by the current transmitter on figure below. Line rejection is 0.0005%/volt and linearity of the transmitter exceeds 0.004%. Here is the schematic diagram of this current loop circuit: The REF-02EZ provides biasing for the current transmitter. The output current is regulated by […]

Read more
Category: Control and Monitoring, Testing and Measurement Tags:

Computer-Controlled 4-20mA Current Loop

Computer-controlled 4-20mA current loop is useful to control some industrial equipments.  By current loop, transmitting the signal over long distant should be resistant from noise interference. This  computer-controlled 4 – 20mA is designed to operate on a single supply over a range of 3.3V to 30V.  The zero reference of 4 mA is set by R1 and calibrated using R2.  […]

Read more
Category: Control and Monitoring Tags:

Single Chip Thermocouple 4-20mA Current Loop Transmiter Circuit

Thermocouples give many benefits compared to thermistor/RTD (Resistance Temperature Devices).  Some advantages of thermocouple are their wider temperature range, their reliability, and their consistency over long period of time. In some cases,  thermocouple calibration  is even unnecessary. Thermocouple temperature sensors are widely used in temperature controllers for boilers, oven,  pressurized reactor, even in high temperature furnace. A general purpose temperature […]

Read more
Category: Control and Monitoring, Testing and Measurement Tags: , ,
1 2