Circuits such as the design described here implement useful tools for a diversity of calibration and testing applications A two-wire loop current generator is a useful tool for the testing, calibration and commissioning of current-to-pressure (I/P) ...
Tracking down rodentia (or otherwise)-caused cable cuts, and differentiating them from normal open circuits, is critical. Evolving the circuit design for expanded functionality makes it even more valuable. It’s just part of the job. Every ...
My recent DI contribution (Another silly simple precision 0/20 mA to 4/20 mA converter, Ref. 1 ) used the LM337 regulator in a novel circuit arrangement to translate an input 0-20 mA current source into a 4-20 mA two-wire transmitter current loop ...
A topic that has recently drawn a lot of interest (!) and no fewer than four separate design articles (!!) here in Design Ideas, is the conversion of 0 to 20 mA current sources into industrial standard 4 mA to 20 mA current loop signals. ...
A recent Design Idea (DI), “Silly simple precision 0/20 mA to 4/20 mA converter,” ( Ref. 1 ) by prolific DI contributor Stephen Woodward uses the venerable LM337 regulator in a creative configuration along with a few passive components, ...
This Design Idea (DI) offers an alternative solution for an application borrowed from frequent DI contributor R. Jayapal, presented in: “A 0-20 mA source current to 4-20 mA loop current converter” ( Ref. 1 ). It converts a 0/20 mA ...
A 4 to 20 mA loop current is a popular terminology with Instrumentation/Electronics engineers in process industries. Field transmitters like pressure, temperature, flow, etc., give out 4 to 20 mA current signals corresponding to the respective ...
I recently published a simple design ( Ref. 1 ) for a platinum resistance detector (PRTD) 4 to 20 mA transmitter circuit, illustrated in Figure 1. Figure 1. The PRTD 4 to 20 mA loop transmitter with constant current PRTD excitation that relies on ...
Accurate, inexpensive, and mature platinum resistance temperature detectors (PRTDs) with an operating range extending from the cryogenic to the incendiary are a gold (no! platinum! ) standard for temperature measurement. Similarly, the 4 to 20 mA ...
In the early days of personal computers, incorporation of one or two (or more) RS-232 serial ports as general purpose I/O adaptors was common practice. Recently, this “vintage” standard has been largely replaced (after all, it is 64 ...