by Eric Bogatin @ edn.com:
The dB (decibel) is one of the most common units in engineering, yet also one of the most confusing, especially when it comes to manipulating S-parameters. Here is how not to be confused.
The Bel is a fundamentally new unit, which was originally established in 1928 by The Bell System to describe sound levels. This scale has since been generalized to relate to the log of the ratio of any two power levels.
The most important principle of the Bel scale to keep in mind is that it is, without exception, by definition, the ratio of powers. It originally related to sound level powers, but has since been generalized to all types of powers.
How to think in dB – [Link]
by w2aew @ youtube.com:
Tunnel diodes are a bit rare these days, but still have uses in special applications including extremely high frequency oscillators, etc. They were commonly used in microwave circuits, oscilloscope trigger circuits, and other applications. This video reviews the basics of tunnel diodes, including the basic properties and simple applications. I refer to these as the “bucking bronco” of diodes because of the IV curve that jumps around, and the fact that these diode will jump into wild oscillation if you just look at them funny!
Basics of Tunnel Diodes and their applications – [Link]
A tutorial on zener diodes and how to use them as voltage clamps, voltage regulators, and how to create audio distortion circuits.
What is a zener diode? – [Link]
The digital multimeter (DMM) is an essential tool in every electronic enthusiasts arsenal.
SparkFun How to use a Multimeter – [Link]
Dave explains why some designs have electrolytic capacitors connected in parallel. The answer is more in-depth than you might think.
9 reasons are given and explained, and then some thermal camera fun on the bench.
EEVblog #742 – Why Electrolytic Capacitors Are Connected In Parallel – [Link]
Using Part-Sim we can verify the response of this RL circuit, and our calculations for the initial, final, and the transition between those conditions. While analyzing this circuit’s response on paper and in Part-Sim, we must use the initial conditions (time and V) and component values. In Part-Sim setting up the switch is the hardest part; with the simulation requiring set up of a voltage controlled switch and AC source with a pulse to get the correct behavior in the circuit. Web based Part-Sim allows you to simulate and verify your calculations any time.
Response of a 1st order RL circuit – [Link]
The Chebyshev filter features a steep roll-off, but has ripple in the pass band, so it is not suited for audio signal use, where a flat response is ideal. The roll off is so fast that the common definition for cut-off frequency does not work for Chebyshev filters. For this type of filter the cutoff is defined as the frequency at which the response falls below the ripple band. This filter is good for removing harmonics and intermodulation in RF applications.
1kHz Chebyshev Filter – [Link]
The most often requested video! In this tutorial Dave explains what Operational Amplifiers (OpAmps) are and how they work. The concepts of negative feedback, open loop gain, virtual grounds and opamp action. The comparator, the buffer, the inverting and non-inverting amplifiers, the differential amplifier, and the integrator circuit configurations are also explained.
Then a practical breadboard circuit to demonstrate a virtual ground and the effect of voltage rail limitations.
OpAmps Tutorial – What is an Operational Amplifier? – [Link]
In semiconductor and electronics industry, a diode is a widely used discrete component. It is a significant element in many electronic circuits and applications ranging from low power signal circuits to power rectification. Based on the functions and ratings, there are different types of diodes. However, all semiconductor diodes contain a PN junction to perform their basic operation.
Diodes – Types and Applications – [Link]
Sine wave oscillator using LM741, a project by A.M. Bhatt of EngineersGarage:
There are different kinds of Sine wave oscillators based on the components used or based on the output frequency that they generate
1. Based on components means if they produce oscillation using resistors (R) and capacitors (C) then they are called RC oscillators and if they use inductor (L) and capacitor (C) then they are termed as LC oscillators
2. Based on output frequency means if they generate frequency in audio range (20 Hz – 20 KHz) then they are Audio Frequency (AF) oscillators. If they generate frequency in low range (100 – 200 KHz) then they are called Low Frequency (LF) oscillators and last, if they generate frequency in high range (in MHz or GHz) then they are termed as High frequency (HF) or Radio Frequency (RF) oscillators.
I am presenting here two such sine-wave oscillators that uses RC components to generate oscillations and they can generate frequency in AF range as well as RF range. The two oscillators are
1. RC phase shift oscillator
2. Wien bridge oscillator
Sine wave oscillator using LM741 – [Link]