Introduction During 1904–1947, the vacuum tube was unquestionably the electronic device of great curiosity and growth. In 1904, the vacuum-tube diode was launched by J. A. Fleming. Soon afterwards, in 1906, Lee De Forest enhanced the device with a third feature, known as the control grid, producing the first amplifier, and named as the triode. […]

## Voltage-Divider Bias in BJT Circuits – More Stability without beta Factor

In the previous bias designs that we learned the bias current ICQ and voltage VCEQ were a function of the current gain (β) of the BJT. But, as we know that β can be vulnerable to temperature changes, particularly for silicon transistors, and also the true value of beta is often not properly identified, it could […]

## Emitter-Stabilized BJT Bias Circuit

We have already studied what is DC biasing in transistors, now let’s move ahead and learn how an emitter resistor can be used for improving the stability of a BJT DC bias network. Applying Emitter Stabilized Bias Circuit The inclusion of the emitter resistor to the dc bias of the BJT delivers superior stability, meaning, […]

## Load-Line Analysis in BJT Circuits

So far we have been studying BJT analysis dependent on the level of β over their corresponding operating points (Q-point). In this discussion we will check out how a given circuit conditions can help in determining the possible range of operating points or Q-points and in establishing the actual Q-point. What is Load Line Analysis […]

## Understanding Ohm’s Law/Kirchhoff’s Law using Linear First-Order Differential Equations

In this article we try to understand Ohm’s Law and Kirchhoff’s Law through standard engineering formulas and explanations, and by applying linear first-order differential equation to solve example problem sets. What’s an Electric Circuit A simplest electric circuit is generally in the form of a series circuit having an energy source or electromotive force input, […]

## What is Transistor Saturation

In the previous post we learned BJT biasing, in this article we will learn what is transistor or BJT saturation and how to determine the value quickly through formulas and practical evaluations. What is Transistor Saturation The term saturation refers to any system where the specification levels have attained the maximum value. We can take the example […]