The LM358 family of dual op amps is among those hoary industry work-horse devices that are inexpensive and still have their uses. These parts’ outputs can approach (and for the inputs even include) their negative supply rail voltage. ...
An interesting analog design problem is the precision current source. Many good designs are available, but most are the three-wire types that can be used as a positive (see Figure 1) or a negative (Figure 2) polarity source, but not both from the ...
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 ...
A classic nonlinear analog function is the squaring circuit. It’s useful in power sensing, frequency multiplication, RMS computation, and many other odd jobs around the lab bench. Figure 1. The squaring amplifier that is fast, ...
The project presented here is a professional quality phantom powered microphone pre-amplifier (Figure 1). The project is built using the INA163 chip from TI. The Chip is a very low-noise, low-distortion, monolithic instrumentation amplifier. R2 and ...
Brief intro to vactrols Vactrols, or both an LED and a light depending resistor (LDR) ( Ref. 1 ) in a light-tight housing, are found in analog music electronics circuits like audio compressors, voltage-controlled amplifiers (VCAs), ...
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 ...
High accuracy, stability, and wide operating range make platinum RTDs (resistance temperature detectors) popular temperature transducers. Signal conditioning these devices requires care to utilize their desirable characteristics. Figure 1’s ...
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 ...