The schematic of a DC machine is depicted below. As you can see it has magnetic poles on both stator and rotor. The torque,…
Category: Learning
Nanoelectronics: MEMS fabrication methods
As mentioned before MEMS can be fabricated with three following methods: bulk micromachining, surface micromachining, and high-aspect ratio micromachining (HARM). MEMS fabrication is based…
Power MOSFET and it’s characteristics
This post tells about power MOSFET characteristics and operating modes. Power MOSFET is a unipolar three-terminal semiconductor device that controls the large amounts of…
Transmission line circuit for mismatched load and generator
Let's consider the most general case of a circuit, where we have the arbitrary loads Z1, Z2 and an arbitrary generator. The input impedance of…
Power MOSFET switching characteristics
It is very important to understand switching characteristics of power MOSFET. To understand the turn-on and turn–off process in power MOSFETs, we have to…
Self-induction – Inductivity
Electromagnetic induction occurs in different ways. For example, when current changes in the circuit, there is different kinds of EMF that occurs in the…
Transmission line losses
All transmission lines are characterised by conductivity and dielectric losses. In some cases losses can be neglected, but not in others. When losses are…
Magnetic field energy
A magnetic field is characterised by the energy parameter. If we turn the switch S to position 2 (Figure 33), the current in the…
Magnetic field in the matter
Let’s consider magnets. Magnets are substances that create the magnetic field around them, without currents through the magnets. However, there are micro-currents that operate…
Matter magnetisation
Let’s consider the solenoid that creates a magnetic field when DC current goes through the coil. The field in the solenoid is uniform, and…