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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975 views

DC to DC power supply Virtual Ground circuit dillema

I am trying to power a circuit with two op-amps that require multiple voltages. The voltage requirements are -14v, +14v, ground/24+. I am trying to power this circuit from a 12vdc power supply. I am ...
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897 views

Can I use one voltage divider to bias multiple points in circuit?

I have 4 nodes in my circuit that require virtual ground of half the power supply voltage. 2 of the nodes are just offset for input signal and other 2 are for op-amp biasing to virtual ground. Can I ...
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664 views

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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1answer
1k views

Phantom Power 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 this with....
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246 views

What does it mean for a signal to be 5V with respect to one leg of an AC input?

This power supply provides 5V with respect to one leg of the 24 VAC input. I'm trying to understand what that means because this provides 1.2 amps and I only need 20 mA for what I'm trying to do. It ...
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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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1answer
996 views

Measuring opamp output voltage (with virtual ground) on arduino

I have been working on a simple project to read the analog voltage input on Arduino. I'm having problem to read the correct value on Arduino. I know what's causing the problem. I'm using the virtual ...
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1answer
458 views

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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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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1answer
2k views

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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3answers
684 views

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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662 views

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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521 views

How do I connect the virtual ground as shown below

This is a circuit for EEG. How do I make the connections labelled as Virtual Ground? Also, how do I connect the 1M trim pot in the top 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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2answers
1k views

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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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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