Electrical4U 
Earth Leakage Circuit Breaker or ELCB An Earth-leakage circuit breaker (ELCB) is a safety device used in electrical installations (both residential and commercial) with high Earth impedance to prevent electric shocks. It detects small stray voltages on the metal enclosures of electrical equipment, and interrupts the circuit if a dangerous voltage is detected. ELCBs help … Read more
The describing function is an approximate procedure for analyzing certain nonlinear control problems in control engineering. To start, let us first recall the basic definition of a linear control system. Linear control systems are those where the principle of superposition (if the two inputs are applied simultaneously, then the output will be the sum of … Read more
Mathematical Modelling of Control System There are various types of physical systems, namely we have: First, we need to understand why we model these systems. Mathematical modelling of a control system involves drawing block diagrams to determine their performance and transfer functions. Now, let’s describe mechanical and electrical systems in detail. We’ll draw analogies between … Read more
What is a Bode Plot? A Bode plot is a graph commonly used in control system engineering to determine the stability of a control system. A Bode plot maps the frequency response of the system through two graphs – the Bode magnitude plot (expressing the magnitude in decibels) and the Bode phase plot (expressing the … Read more
Understanding the transient and steady state responses of control systems begins with defining a few key terms.Standard Input Signals: Known as test signals, these simplify the complex nature of real inputs which often combine multiple signal types, making system analysis more straightforward. So we use test signals or standard input signals which are very easy … Read more
Before introducing state space analysis of control system, it’s important to understand the differences between conventional and modern control system theories. State space analysis, based on modern theory, applies to all systems, including SISO, MIMO, linear, non-linear, time-varying, and time-invariant systems. Let’s explore some basic terms related to state space analysis. State Space Equations Let … Read more
The basic operating principle of an SCR can be understood using the two transistor model of SCR, which combines p and n layers.An SCR is a pnpn thyristor. By bisecting it, we see two transistors: one pnp transistor with J1 and J2 junctions and one npn transistor with J2 and J3 junctions.The relation between the … Read more
Distribution Transformer The step down transformers used for electric power distribution purpose are referred as distribution transformer. There are several types of transformer used in the distribution system. Such as single phase transformer, three phase transformer, pole mounted transformer, pad mounted transformer, and underground transformer. Distribution transformers are generally small in size and filled with … Read more
Turn ON Time of SCR A forward-biased thyristor turns on when a positive voltage is applied between the gate and cathode terminals. This transition from forward blocking to conduction mode has a specific duration, known as the turn on time of an SCR, divided into delay(td), rise time(tr), and spread times(ts). Delay Time of SCR … Read more
Thyristor ratings or SCR (Silicon Controlled Rectifier) ratings are very much required for operating it in a safe zone. The reliable operation can be done when a thyristor does not violate its voltage and current rating during working period. A thyristor, or SCR may have several ratings, such as voltage, current, power, , , turn … Read more