Relay is made up of two elements; the coil and the contact. The coil needs to be energized so that the contact will change state. For detailed analysis on how to drive the relay coil for it to energize read this. In this topic we will jump directly to relay kickback voltage analysis. As mentioned, relay has a coil. This coil
READAuthor: electronicsbeliever
Opto Coupler CTR Explanation
Opto coupler CTR explanation is not well elaborated by other authors and before I was also having hard time of understanding what is it. Current transfer ratio or commonly known as CTR is the ratio of the collector current to the forward current of an optocoupler. It is synonymous to a current gain of a bipolar junction transistor. If this is the first
READ
MOSFET Efficiency Factors for Switching Converters
We will discuss here the three main contributors of power losses of the MOSFET when used in switching converter or switch mode power supply. The main MOSFET efficiency factors are drain to source on state resistance, gate charge and the equivalent output capacitance. Drain to source on state resistance or simply RDSon has a positive temperature coefficient (increases with temperature
READDesigning MOSFET Switch – Comprehensive
MOSFET is not well discussed in the undergrads; much more how to designing MOSFET switch. MOSFET stands for metal oxide semiconductor field effect transistor. Actually it is easier than BJT if we are talking a switch circuit. Nowadays MOSFET is very popular in circuit designs. Such in automotive, power supply and general electronics as a low side and high side
READ
How to Analyze Optocoupler in Feedback System
One of the usual applications of optocoupler is to provide isolation between two ground reference. That is why it is often seen in power supply feedback circuit. How to analyze optocoupler in feedback system is to discussed in this article. Keep on reading below. How to analyze optocoupler in feedback system is not as difficult as you think. However, the lack
READ
Mathcad Step by Step Tutorials for Beginners
In this article I will teach Mathcad Step by Step Tutorials for Beginners. Advance topic will be discussed in another article. There are two parts on this article. The first part is about software familiarization while the second part is about Mathcad computations. Mathcad Step by Step Tutorials for Beginners Part 1: Software Familiarization Open Mathcad software. A blank page
READ
LTSpice Circuit Simulation Tutorials for Beginners
“What is the best free circuit simulation software?” The answer is here. As a solid user of this circuit simulation software, I introduce this to you; LTSpice. “How to Use LTSpice?” “How to Start Simulation in LTSpice?” So many questions in mind, we will answer all these. In this article I will teach LTspice circuit simulation tutorials for beginners. Advanced
READOperation of a Switch Mode Power Supply
How a Switch Mode Power Supply Works? What is the operation of a switch mode power supply? A switch mode power supply works by continuously switching on and off a semiconductor switch. This semiconductor switch is can be a MOSFET or a BJT. The former is more popular than the latter. When the switch turns off, there is no current
READ
How to Drive a Transistor into Hard Saturation
How to drive a transistor into hard saturation? In using a transistor to operate as a switch you must drive it into saturation. Saturation happens when the collector current cannot further increase despite there is base current increase. The saturation level of every transistor varies. The usual range is from 0.7V to ideally zero. For instance for a BC817-25 transistor,
READ
BJT Operation Modes
BJT operation modes are at cut-off, saturation and active or linear. At cut-off, simply the BJT is not operating, say the base-emitter voltage requirement is not meet. The corresponding collector-emitter voltage is the same with the collector supply. At saturation the other hand, the BJT is driven into the point wherein its collector current can no longer increase despite of the increase
READ