Fig. Thermocouple (source: sterlingsensors.co.uk) What is a Thermocouple? A thermocouple consists of a pair of dissimilar wires joined at one end. It is an active transducer. On the other hand, RTD and thermistors are passive transducers. Thermocouple work on the principle of Seebeck effect. According to Seebeck effect, if two dissimilar metals are joined together … Read more
Piezoelectric Transducer A piezoelectric transducer is one that can generate a voltage proportional to the stress applied to it. These transducers work according to the piezoelectric effect. When a mechanical force or pressure is applied across the piezoelectric crystal, an electric potential appears across the surfaces of crystal. This generation of electric potential is due … Read more
Hall Effect Transducers Hall Effect Transducers are the transducers which work on the principle of hall effect. According to hall effect, if a conducting material strip carries current in the presence of a transverse magnetic field; an EMF is produced between two edges of the conductor in a direction perpendicular to both the magnetic field … Read more
In the previous article, we have learned about Maxwell bridge. It is a modification of Maxwell’s bridge. The circuit diagram for Hay’s Bridge is shown below. It uses a resistance in series with a standard capacitor. L1=unknown resistance having a resistance R1 R2, R3, R4=known non-inductive resistance C4=standard capacitor At balance, e1e4 = e2e3 Separating real … Read more
If someone chokes a person, they can’t breathe, the flow of air is stopped. The name Choke comes from the same idea. There is some energy that we want to Choke or prevent flowing in our circuit in or out of our circuit. We might want to prevent the power or ground lines in a … Read more
Programmable Logic Controllers (PLCs) Programmable Logic Controllers (PLCs) are the microprocessor controller devices situated at the remote sites of the plant or at the field of the process systems. PLCs purpose is to monitor the process parameters located at the field and adjust the outputs based on the inputs received by the PLCs. PLCs will … Read more
Virtual instrumentation combines thought industrial Technologies, like the personal computer with versatile software and a large variety of measurement and control hardware. Engineers use virtual instrumentation to bring the facility of flexible software and personal computer technology to test, control, and design applications making accurate analog and digital measurements. Virtual instrumentation is a pc software … Read more
Ammeter Shunt is used for the measurement of heavy current using an Ammeter. Ammeter Shunt is basically a low resistance connected in parallel with the moving coil so that most of the current is bypassed by the Shunt and hence only a small current flows through the moving coil. Why do we need Ammeter Shunt … Read more
Frequency and Voltage are two important parameters which decide the healthiness of the electrical grid at a particular instant of time. Frequency fluctuations occur in the electrical grid when there is a mismatch between the amount of power generation and amount of power demand. Both under frequency and over frequency operation is harmful to the … Read more
Frequency variation in the power system exists due to the mismatch between the supply of power and demand for the power. Voltage variations exist in the power grid is due to the mismatch in the reactive power between demand (MVAR) and available. In spite of all these variations, there is a certain limit for the … Read more