Questions tagged [virtual-ground]
In electronics, a virtual ground (or virtual earth) is a node of a circuit that is maintained at a steady reference potential, without being connected directly to the reference potential.
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What is the use of an op-amp whose output and inverting input are connected to ground?
I am in first year of Engineering school and I was given an assignment containing this circuit, which drives pressure sensors in a pitot tube :
I am struggling to understand the whole circuit, and ...
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How make a dual +-12V supply from a 24V SMPS
I'm trying to power a home-made load cell transmitter using a 24V single SMPS. I need to make +12, 0 and -12 Volts that are capable of 50mA. I wish to power multiple channels of opamps and bridges.
I ...
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Virtual Ground Paradox?
I'm unable to come to terms with something I think is a paradoxical situation relating to the virtual ground of an Operational Amplifier.Please pardon me if this is a really stupid question.
When the ...
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Any downside to using a charge pump for an op-amp negative supply
Background: I'm often building audio op-amp circuits for various purposes, and for small projects usually prefer single "wall adapter" supply. So for a ground reference I'll either use a simple ...
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Isolating audio ground between devices
I'm planning a build for a guitar amplifier with 2 stages, the first being a tube pre-amp and the second stage being a solid state amplifier. Both amplifiers will be powered from the same source, a ...
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Op-amp based virtual ground with BJT buffer
I have a line-level audio circuit (2-channel balanced to unbalanced input circuit feeding a stereo volume control IC feeding a 2-channel unbalanced to balanced output circuit) which needs a dual PSU (±...
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How to make a simple negative power supply
I want to experiment with amplifiers but I need a negative power voltage source.
I looked for some circuits but as far as I found they either are not simple & reliable or require an IC.
Is there ...
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Battery and virtual ground
I have a 24V battery and I'm trying to obtain a virtual ground from it. 90% of the circuits I found limit themselves to an opamp, which has very low current sinking. I'm trying to add a pair of ...
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Virtual earth (ground) or "mid-rail generator"
In a recent question I (rightly or wrongly) said in a comment that calling a mid-rail generator (two resistors and a smoothing capacitor) a "virtual ground" was wrong and that the term "virtual ground"...
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JFET Burn Out in Wien Bridge Oscillator
I have a simple Wien Bridge Oscillator (with JFET gain control) circuit pictured below. This circuit works as expected at lower voltages (+/-9 V), but I am running into some problems with higher ...
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Voltage Balun 1:1
somewhere I have seen that it is possible to build a Balun by using a transformer in the following way:
The explanation I have found is that the fact that the ground is only at the primary coil will ...
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Simple single-supply op amp virtual ground questions
I found this circuit online and made it and it works.
It uses an LM358 op amp to amplify an oscillation from a 555 in astable mode.
simulate this circuit – Schematic created using CircuitLab
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Op amp rail splitter virtual ground shifts when LED is on
I have a 9V power supply. I split it in half using a voltage divider buffered through a TL071 op amp. I use the +4.5V rail to power an ATmega328P. The microcontroller has one pin attached to an LED ...
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What is the purpose of the opamp in an integrator circuit?
What is the exact role of opamp in an integrator circuit....?
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Single supply op-amp
In this example,
there is a "A TLV2461 operational amplifier IC is connected to provide a virtual ground for proper operation of the TLC074 from a single supply voltage."
I don´t quite ...
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Op amp Power supply splitter with totem pole
I want to make a +/- 2.5 V rail from a 5 V supply using an op-amp. I was wondering if I could use a totem pole for driving the output like this:
Image from here
But while I was looking at it, I ...
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Common ground in low side current sensing
I've asked this question a while back and user/Transistor told me that the circuit will be floating and drift without a common ground, he suggested a virtual ground. but in this case we already have a ...
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Operational Amplifier - Virtual ground
In the question above I was asked to solve the general shape of Vout, and the exact values in t=0.5ms,1ms.
My question is - can I approximate a constant virtual ground in the negative input of the ...
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Use of virtual ground to split ground loops?
So I have a "broadband" signal (DC-5MHz) which I'd like to send over coax cable to two other circuits referenced to the same ground. Simply floating the other two circuits is not an option for ...
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Op-Amp Integrator's virtual ground
I have been using op-amp TL072C in charge integrator configuration.
R = 1k Ohms and C = 100 uF.
Vin is a DC signal of 1 V.
VCC = 10 V and VSS = -10 V.
I get the expected output which is VSS, when a ...
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What is the difference between real ground and virtual ground in opamp?
I understand what a real ground for a Opamp is.It is a terminal which is physically connected to ground or earth which acts as the reference point for the entire circuit.
But what do we mean by a ...
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What is the correct schematic symbol to use for virtual ground?
I'm following the design of a circuit requiring a power supply to provide something the author calls virtual ground, \$V_{gnd}\$. The circuit look like this:
However, I'm using KiCad for the design ...
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Phototransistor with virtual ground opamp design
I am setting up a high sensitivity light detection circuit and came across this thread just a bit ago:
Phototransistor transimpedance amplifier
Within it was a response with this image:
My question ...
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Replacing a virtual ground circuit with center tapped transformer
I just bought a cheap headphone amp (those 47 Amp). I aiming to replace the voltage-divider-virtual-ground circuit with a 12v-0v-12v transformer (ofc with rectification). I checked the NE5532's VCC+'s ...
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What does this rail-splitter-like circuit do?
I'm repairing an audio amplifier for a car. It has a switching supply that generates +/- 50V rails from the ~12V battery. In the output section of the amplifier, I found this small circuit with ...
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Microphone supply circuit comparison?
I'm going to connect an electret mic (WM-61A) to my computer's "mic in", and am very confused on the reasoning behind a couple different diagrams/schematics that could possibly be used to do ...
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How to split 5V USB input into 4 rails (+/-5V, +/-15V)? Problem with combining two virtual grounds
Problem: I have 5V input from USB, I need to split it into four rails with +/-5V and +/-15V.
Currently done: I have built the following circuit in a breadboard.
I have measured the outputs with a ...
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Transistor getting hot in rail splitter circuit
I designed and prototyped the circuit below. The circuit works as expected but Q2 is getting really hot during operation. I simulated it in LTSpice and saw that Q2 draws more current but the range is ...
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Why do some audio amplifiers connect the power ground to the signal ground?
Trying to add a MIDI synthesizer & speakers to a keyboard here. Here's the schematic:
simulate this circuit – Schematic created using CircuitLab
But I was getting annoying crackling and ...
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Virtual ground circuit capacitor's function?
What is the function of the capacitors in this virtual ground circuit?
I've read on the fly that C75 is to maintain a linear impedance for higher frequencies, but under which conditions I don't know.
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What is behavior of this virtual ground circuit when sourcing/sinking current?
simulate this circuit – Schematic created using CircuitLab
This is the virtual ground circuit from a battery-powered headphone amplifier(direct link to schematic PDF). What is the behavior of ...
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Driving LM386 with signal referenced to virtual ground
I'm working with a chip that outputs audio signals to headphones that are referenced to a virtual ground. Since I'm connecting the audio signal to a speaker instead of headphones, I'd like to ...
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Current through virtual ground in op-amps
I am currently trying to understand op-amps. I found a video on youtube about I to V convertor and I am wondering since we have a virtual ground, due to $$V_1 = V_2$$ and then there is ground right ...
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Using ground vs virtual ground in a single-supply Sallen-Key low-pass filter
This is the filter in question (courtesy of Wikipedia):
The opamp supplies are +5 V and 0 V, and I'm already using a buffered 2.5 V reference elsewhere in the circuit. I'm debating whether or not to ...
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Understanding ground when using a USB vs a benchtop oscilloscope
I am trying to understand how a USB oscilloscope can furnish a proper ground from which to take measurements.
If I'm not mistaken, my benchtop scope which is powered by my wall outlet at AC 120V, has ...
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Creating Neutral node on Three phase Inverter
I want to create a neutral node at the output of a 3-phase Inverter for ACIM. Is it possible to do that by adding 3 resistors at the Inverter outputs and join them together to get the neutral node? ...
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Virtual Short Concept in an Op-Amp
By virtue of the open-loop gain being infinity for an ideal op-amp, the two input terminals are said to be virtually shorted.
Yet, the virtual short concept is only applied to op-amps in negative ...
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Operational amplifiers and virtual ground
Could you physically clarify why we use virtual ground in op amps?
I have seen the argument that since A(open loop gain) tends to infinity, we need the difference in inputs to tend to zero(to maintain ...
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Virtual AC ground for AC power main
I have the following problem: I use to perform electrical experiments in a small room in an apart where other persons repair computers. It sometimes happens that I make the main differential switch ...
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Virtual ground concept in electronic circuit
This is my current sense circuit that I connect to Arduino in order to measure how much current a load draws.
As you can see at the bottom of the image there is a -5 V voltage source connected to the ...
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Differential amplifier and different ground
I am designing a circuit to measure the voltage across the output of buck converter. With different ground for the buck converter and the micro controller, with respect to which ground will the ADC ...
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Connect a DC/DC converter to a virtual precision ground in KiCad
I'm trying to design a circuit which steps up 5V to 12V using a DC/DC converter and then use a virtual precision ground TLE2426 to split the 12v to +/-6V.
I'm using this design in KiCad:
I'm having ...
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What causes a voltage drop at the input of this TL082CP Op-Amp?
I am breadboarding a circuit using a TL082CP Op-Amp, and I am reading consistent values with the multimeter.
The Op-Amp stage is powered with a single 9V battery, like this:
The Op-Amp stage looks ...
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Understanding current sourcing and sinking in TL2426 rail splitter
I have a 40dB active bandpass filter being powered off a single rail power supply with the TL2426 providing a virtual ground so I can get a dual power supply configuration. Currently, I'm having ...
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Two grounds when using transistor switching
Background
I'm designing a small circuit in which an MCU and all its peripherals should be shut down unless a certain condition is met, which is represented by a switch in this simplified schematic.
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Design of variable split rail power supply
I'm attempting to drive an array of piezo transducers and am struggling to find a good design capable of driving from around +-5V to +-30V at about 2A for my testing. There are about 12 sets of ...
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Bipolar output from DAC with unipolar supplies
I want to use a unipolar 12-bit DAC (MCP4725) as a function generator with bipolar output (from -2.5 to +2.5V). Problem is, I only have two supplies of +5V and +12V referenced to the same ground, so ...
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Virtual ground supply for audio-applications
The most common solution to provide positive and negative voltage to supply an OP-amp would be to use a voltage divider and another OP-amp. In this way the voltage "on the top" of the ...
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Should I connect metal enclosure to -V or to virtual ground?
I've built a headphone amplifier powered by a switch-mode 2-pin wall wart power supply. Internally a virtual ground is created by dividing and buffering the supply voltage. Input and output signals ...
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Would a current feedback op-amp work well as a precision ground reference?
I've been looking into precision ground reference circuits to form ±5V rails from a 10V supply for a project I'm working on, and noticed that current feedback (CFB) op-amps have some desirable ...
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