Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

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.

Virtual ground refers to a circuit element not directly connected to ground, held at a reference voltage. This reference voltage need not be the same voltage as ground either.

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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 more precisely the first op-amp, which output (pin…
Magix
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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 don't have much budget and availability of…
Ohbhatt
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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 'Negative Feedback' in an Op-Amp (Ideal) makes…
Sumanth
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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 31v DC power brick. The pre-amp will be powered…
Jim Valentine
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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 resistor pair with a capacitor, or better, a spare OP…
Randy
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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 (±12V or ±15V). I have some trouble sourcing parts…
Dan Kadera
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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 any simple way to get negative power supply without…
Mordecai
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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 voltage supplies (+/-16 V). I believe the JFET…
Two Nybble
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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 transistors in push pull configuration, but my…
gscofano
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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" is reserved for when using negative feedback on…
Andy aka
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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 noticed that since both transistors need to be…
Christianidis Vasileios
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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 make that the signal at the primary coil is…
Kinka-Byo
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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 How were the values of R2 and R3 arrived at? I know they…
thatsagoal
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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 through a 330-ohm resistor. The problem that I'm…
Willis Blackburn
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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 understand the advantage of having a mid-bias point using a…
Status Re
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