Tricky but Easy Electrical Engineering!
Harmonics in the excitation current of Transformer is due to Hysteresis. As we know the relationship between Magnetic Flux Density, B and Magnetic Field Intensity, H is not linear as shown in figure below. Also, B = Flux (Ø) / Area (A), and H = NI where N = Number of turns and I = … Read more
Triggering basically means switching. The way in which a switch or an event is triggered can be different, based on the user’s requirements. Edge and Level Triggering, are both common terms when using sequential circuits like Flip Flops triggered by a clock signal. Essentially, this is how a clock signal looks like, LEVEL TRIGGERING: … Read more
In AC circuit breakers/ arc extinction is achieved at the natural current zero of the AC waveform used. But in DC circuit breakers / natural zero of voltage and current is not available as both are continuously available. Thus for extinction of an arc, artificial current zero is required to be introduced. Such an artificial … Read more
Isolation Transformer: An isolation transformer is a Transformer used to transfer electrical power from a source of alternating current (AC) power to some equipment or device while isolating the powered device from the power source, usually for safety reasons. Isolation Transformers provide galvanic isolation and are used to protect against electric shock, to suppress electrical … Read more
In a capacitor, we always have a Displacement Current and never a Conduction Current under normal conditions i.e. when we apply a potential difference across a Capacitor which is below its specified maximum Voltage. Conduction Currents flow when electrons actually move. But in Displacement Current, no charge carriers are involved. It’s just the variations in … Read more
As we know, both Silicon and Germanium are semiconductor devices. But the present trend is to use Silicon instead of Germanium in many devices like SMPS etc. The reasons for using Silicon Diodes over Germanium Diodes this are: At room temperature, Silicon crystal has fewer free electrons than Germanium crystal. This implies that silicon will … Read more
Cogging phenomenon is observed in Squirrel Cage Induction Motor during starting for certain combination of Stator and Rotor Slots. In Cogging motor fails to start at all. For better understanding a view of Stator Core Laminations, Stator Core and Rotor of Squirrel Cage Induction Motor is shown in figure below. Squirrel Cage Induction Motor Stator … Read more
When the electricity is flowing normally, the fuse permits the power to pass unobstructed across its filament, between circuits. If an overload occurs, the filament melts, stopping the flow of electricity. Fuse is a one time use device and melts when excess current passes through it and protects the other devices in the circuit. … Read more
RLC Series Circuit is shown below. We will consider RLC Series Circuit for Resonance. At Resonance, Impedance of Inductor = Impedance of Capacitor Therefore, ωL = 1/ωC, where w is angular frequency =2πf ω2LC = 1 ω2 = 1/LC Therefore, at Resonance the Impedance of RLC circuit = R Since the … Read more
A commutator in a DC Machine has alternate bands of Copper and mica. Now when the armature starts to rotate by an external force (in DC Generator), the coils situated in the armature also rotate. The coils are shorted via brush segment with alternate change in influence of poles. This alternate change via the commutator … Read more