A variable-gain (VGA) or voltage-controlled amplifier (VCA) is an electronic amplifier that varies its gain depending on a control voltage (often abbreviated CV). VCAs have many applications, including audio level compression, synthesizers and amplitude modulation. A crude example is a typical inverting op-amp configuration with a light-dependent resistor (LDR) in the feedback loop. The gain of the amplifier then depends on the light falling on the LDR, which can be provided by an LED (an optocoupler). The gain of the amplifier is then controllable by the current through the LED. This is similar to the circuits used in optical audio compressors. A voltage-controlled amplifier can be realised by first creating a voltage-controlled resistor (VCR), which is used to set the amplifier gain. The VCR is one of the numerous interesting circuit elements that can be produced by using a JFET (junction field-effect transistor) with simple biasing. VCRs manufactured in this way can be obtained as discrete devices, e.g. VCR2N. Another type of circuit uses operational transconductance amplifiers. In audio applications logarithmic gain control is used to emulate how the ear hears loudness. David E. Blackmer's dbx 202 VCA, based on the Blackmer gain cell, was among the first successful implementations of a logarithmic VCA. Analog multipliers are a type of VCA designed to have accurate linear characteristics, the two inputs are identical and often work in all four voltage quadrants, unlike most other VCAs. (Wikipedia).
Electrical Engineering: Ch 5: Operational Amp (26 of 28) The Instrumentation Amp (Variable Gain)
Visit http://ilectureonline.com for more math and science lectures! In this video I will explain and find the variable gain of the instrumentation amplifier. Next video in this series can be seen at: https://youtu.be/ndaKsr7NW5A
From playlist ELECTRICAL ENGINEERING 5: OPERATIONAL AMPLIFIERS
Electrical Engineering: Ch 5: Operational Amp (13 of 28) Open Loop Gain vs Closed Loop Gain
Visit http://ilectureonline.com for more math and science lectures! In this video I will calculate the voltages of an open-loop gain vs a closed-loop gain. Next video in this series can be seen at: https://youtu.be/Gmy1ciTiEbs
From playlist ELECTRICAL ENGINEERING 5: OPERATIONAL AMPLIFIERS
How To Calculate The Voltage Gain of a Transistor Amplifier
This electronics video tutorial explains how to calculate the voltage gain of a transistor amplifier. It explains how to calculate the base current of an emitter feedback bias circuit and a voltage divider bias circuit which is useful in calculating the AC emitter resistance of the circui
From playlist Electronic Circuits
Electrical Engineering: Ch 5: Operational Amp (25 of 28) The Instrumentation Amplifier
Visit http://ilectureonline.com for more math and science lectures! In this video I will explain and find the V(output) of the instrumentation amplifier. Next video in this series can be seen at: https://youtu.be/kZ0F65AwlAY
From playlist ELECTRICAL ENGINEERING 5: OPERATIONAL AMPLIFIERS
https://www.patreon.com/edmundsj If you want to see more of these videos, or would like to say thanks for this one, the best way you can do that is by becoming a patron - see the link above :). And a huge thank you to all my existing patrons - you make these videos possible. Here I descri
From playlist RF Amplifier Design
Electrical Engineering: Ch 5: Operational Amp (7 of 28) Summing Amplifier (Inverting) Example 2
Visit http://ilectureonline.com for more math and science lectures! In this video I will find the output voltage of an inverting operational amplifier where the input voltages have alternating sources. Next video in this series can be seen at: https://youtu.be/2cqgg0PPRNg
From playlist ELECTRICAL ENGINEERING 5: OPERATIONAL AMPLIFIERS
Electrical Engineering: Ch 5: Operational Amp (3 of 28) Inverting Amplifier-Basic Operation Example
Visit http://ilectureonline.com for more math and science lectures! In this video I will find the output voltage and the frequency of an inverting amplifier. Next video in this series can be seen at: https://youtu.be/c3u9RRIVkok
From playlist ELECTRICAL ENGINEERING 5: OPERATIONAL AMPLIFIERS
Operational Amplifiers - Inverting & Non Inverting Op-Amps
This electronics video tutorial provides a basic introduction into operational amplifiers. it includes examples such as inverting and non-inverting op amps. It explains how to calculate the closed loop voltage gain of such amplifiers as well as the output signal voltage. 741 Op Amp: ht
From playlist Electronic Circuits
1. Introduction and Basic Concepts
MIT Electronic Feedback Systems (1985) View the complete course: http://ocw.mit.edu/RES6-010S13 Instructor: James K. Roberge License: Creative Commons BY-NC-SA More information at http://ocw.mit.edu/terms More courses at http://ocw.mit.edu
From playlist MIT Electronic Feedback Systems (1985)
Electrical Engineering: Ch 5: Operational Amp (6 of 28) Summing Amplifier (Inverting) Example 1
Visit http://ilectureonline.com for more math and science lectures! In this video I will find the output voltage of an inverting operational amplifier. Next video in this series can be seen at: https://youtu.be/jZdhtst4T3k
From playlist ELECTRICAL ENGINEERING 5: OPERATIONAL AMPLIFIERS
EEVblog #1228 - Do Digital Scopes Have REAL Verniers?
Do digital oscilloscopes have REAL vertical vernier controls? Let's probe a scope up the clacker to find out! Get better accuracy on your oscilloscope: https://www.youtube.com/watch?v=8iE28oGtayQ Forum: https://www.eevblog.com/forum/blog/eevblog-1228-do-digital-scopes-have-real-verniers/
From playlist Oscilloscope Tutorials
3. Introduction to Systems with Dynamics
MIT Electronic Feedback Systems (1985) View the complete course: http://ocw.mit.edu/RES6-010S13 Instructor: James K. Roberge License: Creative Commons BY-NC-SA More information at http://ocw.mit.edu/terms More courses at http://ocw.mit.edu
From playlist MIT Electronic Feedback Systems (1985)
MIT Electronic Feedback Systems (1985) View the complete course: http://ocw.mit.edu/RES6-010S13 Instructor: James K. Roberge License: Creative Commons BY-NC-SA More information at http://ocw.mit.edu/terms More courses at http://ocw.mit.edu
From playlist MIT Electronic Feedback Systems (1985)
2. Effects of Feedback on Noise and Nonlinearities
MIT Electronic Feedback Systems (1985) View the complete course: http://ocw.mit.edu/RES6-010S13 Instructor: James K. Roberge License: Creative Commons BY-NC-SA More information at http://ocw.mit.edu/terms More courses at http://ocw.mit.edu
From playlist MIT Electronic Feedback Systems (1985)
Basics of quantum measurement with quantum light by Michael Hatridge
DATE: 04 June 2018 to 13 June 2018 VENUE:Ramanujan Lecture Hall, ICTS Bangalore Non-Hermitian Physics-"Pseudo-Hermitian Hamiltonians in Quantum Physics (PHHQP) XVIII" is the 18th meeting in the series that is being held over the years in Quantum Physics. The scope of the program on Non-H
From playlist Non-Hermitian Physics - PHHQP XVIII
Lec 11 | MIT 6.002 Circuits and Electronics, Spring 2007
Small signal circuits View the complete course: http://ocw.mit.edu/6-002S07 License: Creative Commons BY-NC-SA More information at http://ocw.mit.edu/terms More courses at http://ocw.mit.edu
From playlist MIT 6.002 Circuits and Electronics, Spring 2007
Quantum measurement of coherent states and qubits by Michael Hatridge
Non-Hermitian Physics - PHHQP XVIII DATE: 04 June 2018 to 13 June 2018 VENUE:Ramanujan Lecture Hall, ICTS Bangalore Non-Hermitian Physics-"Pseudo-Hermitian Hamiltonians in Quantum Physics (PHHQP) XVIII" is the 18th meeting in the series that is being held over the years in Quantum Phys
From playlist Non-Hermitian Physics - PHHQP XVIII
What is an op amp? Operational Amplifier tutorial & super spy microphone circuit
Afroman goes over the basics of how to use an op amp (operational amplifier) to amplify tiny voltages, and builds a circuit to listen to very faint sounds with a microphone. LM324 Quad op amp: http://www.amazon.com/exec/obidos/ASIN/B0088VAA80/afromods-20 Circuit diagram: http://www.afrote
From playlist Recommended videos
Electrical Engineering: Ch 5: Operational Amp (19 of 28) Design a Circuit: Example 3
Visit http://ilectureonline.com for more math and science lectures! In this video I will design a circuit where vo=5(v2-v1) using a difference amplifier. Next video in this series can be seen at: https://youtu.be/yTkC6vdtHaY
From playlist ELECTRICAL ENGINEERING 5: OPERATIONAL AMPLIFIERS