Questions tagged [dc-offset]
The dc-offset tag has no usage guidance.
102
questions
2
votes
1answer
82 views
How does this DC offset sinwave input work?
I have learned that this circuit will move the sin wave up to a DC points due to the voltage divider, that is:
V_out = V_in + Vcc*R2/(R1+R2)
I was using LTSpice to simulate this and it works, I try to ...
0
votes
3answers
70 views
Is using a passive RC high pass filter at the output of an opamp a good method to remove DC offset?
All the information I am able to find related to this discuss about AC coupling the inputs of an amplifier but never the output. I wish to know if there are any issues with AC coupling at the output. ...
0
votes
0answers
38 views
How to block DC offset voltage on a potentiostat output?
I have an AUTOLAB potentiostat: working electrode (WE, Pt wire), counter electrode (CE, Pt wire), reference electrode (RE, Ag/AgCl solid state).
I would like to capacitively couple the potentiostat ...
3
votes
3answers
712 views
How to implement gain and offset in a single opamp?
I tried designer here in this page. But my particular case (Case 2) seems not working in the page.
Then I Read this document and my case there, is section 4. But my calculation results are not ...
1
vote
1answer
62 views
Remove DC comp offset of AC current
I am attempting to build a circuit that excites a sensor which requires an AC current of ±1mA and 20kHz frequency. For this, I used voltage to current converter integrated circuit XTR110, which is ...
1
vote
1answer
70 views
Unkown DC offset of an isolation amplifier circuit design
I am designing an isolation amplifier that consists of the following blocks:
A comparator which produces a PWM signal
A coupling capacitor that achieves galvanic isolation
A voltage follower that ...
1
vote
3answers
95 views
Low-frequency high.pass filter drifts with temperature
for a phase sensitive measurement, I would like to have the DC offset of a signal cancelled. The AC-signal will be amplified and then the phase of it is measured in reference to another AC-signal.
My ...
4
votes
5answers
282 views
Accurately amplifying a number of current sense transformers
I've got 16 current sense transformers that are being used to monitor AC loads. The SCTs are current output type, producing 50mA on a 100A load. The maximum burden resistance is 10Ω, thus the voltage ...
1
vote
2answers
104 views
What kind of op-amp circuit is this?
I am trying to understand the circuit have shown below. As far as I tried, it seems a differential amplifier for me. So, I tried to solve it in the way we deal with DC signals. But I failed to solve ...
3
votes
2answers
80 views
Wheatstone bridge to create offset
While comparing schematics of two old analog oscilloscopes (Tektronix 475 and Goldstar 9020,) I was expecting many differences to get better frequency response since the first is a 250MHz and the ...
3
votes
0answers
99 views
Sawtooth VCO DC offset issues
[Apologies in advance for possible misuse of terminology. I don't have any formal education in EE and am mostly self taught, so I may be lacking in some fundamentals.]
I am trying to design a discrete ...
0
votes
0answers
50 views
What is the practical difference in this DC offset remover?
I am working on audio signal oscillators. My oscillator generates 0V to +5V triangle wave.
Then I'm removing DC bias to get -5V to +5V signal.
I have found two examples on how to do this:
What is the ...
1
vote
1answer
56 views
high voltage DC biasing on top of low voltage AC with floating load
I am in process of designing a power supply for heating a filament in an electron gun. The AC heating current has to float on top of DC high voltage acceleration voltage. The following circuit seems ...
0
votes
2answers
268 views
Meanwell Led driver: internal 3-in-1 dimming circuit
In Meanwell led drivers like the ones from the XLM, HLG or LCM families, how does the internal circuitry for the 3-in-1 dimming feature (0-10V, 10V PWM, 0-100kOhm) look like?
I use a LCM-25 in my ...
0
votes
1answer
106 views
ua741 DC offset on the output
I have ua741cn and connected it to 10V.
V_+ =10V
V_- =GND
Just to verify I have a valid chip I did a little test.
I connected the non-inverting input to GND and the inverting to 10V I would expect the ...
0
votes
2answers
77 views
DC offset before signal being fed into an instrumentation amplifier from a bio potential source
I am trying to design an instrumentation amplifier, having 2 bio-potential sources as its differential inputs, each having peaks in the order of 10's of uV and a frequency band of 3-50 Hz. One of the ...
0
votes
2answers
63 views
Is there a reason the offset of this opamp is done like this?
I recently found this schematic from a project at university (drawn by our lecturer). It's a low pass filter that also adjusts the gain, and adds an offset of 1.5 V (the input signal can be positive ...
0
votes
2answers
103 views
What is causing the DC Offset in Mirrored Howland Current Pump Circuit
I am creating a current source to try to expand my knowledge about electronics design. After some research I decided to build the Howland setup since I want to develop a bipolar current source. The ...
0
votes
2answers
183 views
OpAmp Spice Model: Offset vs Common Mode Voltage
The spice Model of the OPA350 specifies that the DC Offset Voltage vs Input Common Mode voltage is implemented in the model. If I do the simulation however, all I can see is a linear trace, when x ...
0
votes
1answer
121 views
bias a signal with DC input coupling, but without attenuation?
I want to bias the analog signal present on an MCU output pin. This signal varies between 0v and ≃3V, I need to shift it down to -/+1.5V range. Most importantly, I need to keep any DC offset ...
1
vote
1answer
177 views
Why do we need differential amplifier after Transimpedance amplifier?
I am implementing the circuit published in AN3025 Transimpedance Amplifier Design as shown below.
When I am simulating this circuit, a few questions come to mind:
Q1. Why do we need a differential ...
1
vote
3answers
479 views
Offset and scale a DAC output with opamps
I am trying to make a simple oscillator controller with an arduino and a DAC, to learn electronics.
I need to send a voltage between 12V and 17V to my oscillator to control its frequency. I got a 24V ...
1
vote
1answer
860 views
DC offset for AC signal
Hi guys, I am looking for some clarification regarding how to create a DC offset for an AC signal. Attached to this post is a quick schematic that I have drawn. Am I correct in saying that by ...
0
votes
3answers
533 views
Adding DC offset to PWM through a unity gain buffer
I have a PWM signal with a period of 200uS and a duty cycle of 20%. For prototyping reasons (this is simulating a pulse that I'll be receiving from circuitry later on in the project), I want to read ...
1
vote
2answers
78 views
Large signal with DC offset matching to ADC with input centered around 0V
I'm new to this forum, so plear bear with me.
I have a 0 to 23v signal coming from a transimpedance amplifier that I need to squeeze into -2.5v to 2.5v input for an ADC. The signal is first put into ...
0
votes
3answers
230 views
Circuit to adjust -30V to +30V input to 0 to 3.3V for ADC? [duplicate]
Currently working on an oscilloscope design that would require each channel to be able to take in between 30VPP, -30V to +30V, which will go to an ADC which has a maximum input of 3.3V.
What types of ...
0
votes
1answer
1k views
How to remove DC offset (and make average DC value 0V) from ADS1261 square wave AC-excitation circuit
I am attempting to remove the DC offset from the 1 kHz, ± 2.5 V, AC square wave output pins of an ADS1261 (http://www.ti.com/lit/ds/symlink/ads1261.pdf). However, when measured on the oscilloscope (...
1
vote
1answer
82 views
AD620 reference terminal problem
I'm trying to add a DC offset level to a sine signal through an instrumentation amplifier (as the figure below shows.)
The problem is that, in the simulation, everything works perfectly, however, in ...
14
votes
2answers
2k views
Does driving a speaker with a DC offset AC signal matter?
Do these two input signals have different effects on a speaker?
An AC signal with some value of DC offset.
Same AC signal but centered at 0 V.
0
votes
1answer
156 views
Single supply inverting OP amp. Problem: half signal at output
I have built a simple inverting amplifier circuit with LM4565 operational amplifier. But only half of the signal appears at the output of the circuit and the gain looks wrong as well. Could anyone ...
1
vote
1answer
325 views
How to compute DC offset of analog circuit?
I have an analog circuit which has an input voltage range Vin of 5V - 10V and output voltage Vout.
One can assume that the circuit has been simulated and a DC sweep of Vin with a range from -10V to +...
0
votes
2answers
413 views
Does this Sallen and Key filter work on a single supply and does the input offset matter?
This is the schematic for a Sallen and Key from the Doepfer Musikelektronik website:
simulate this circuit – Schematic created using CircuitLab
I intend to run this in a synth, the oscillators ...
0
votes
3answers
291 views
AD620 pH probe has a positive voltage offset!
I am a chem eng. but little background in electronics.
I'd like to interface a pH probe with an AD620A, the original PCB that came with pH probe was damaged by a current leak in the solution.
I made ...
0
votes
1answer
200 views
Waveshare ADC Board changing analog input range [duplicate]
This question has been redirected from raspberry pi community. Some of the questions have been answered by @Milliways, so those questions have been edited out.
I'm using this Raspberry Pi High-...
0
votes
0answers
104 views
Remove Sensor Voltage Offset ADC [duplicate]
I've got a pressure sensor and a flow sensor. Both have a 5V span, but have a (different) null offset i.e. at zero pressure (gauge) or zero flow they read ~2V and ~1V respectively.
I am using an ...
4
votes
1answer
305 views
Analog switch on an instrumentation amplifier input
I'm working on a project for school that involves a configurable input stage (AC/DC coupling and variable input impedance) connected to an instrumentation amplifier. I am wondering whether I will ...
0
votes
1answer
411 views
Single supply opamp colpitts oscillator
I'm designing a Colpitts oscillator with a single supply rail-to-rail opamp powered with 3.3 V. The positive input of the opamp is set to VDD/2 to offset the negative part of the oscillations so ...
0
votes
1answer
686 views
How do I remove the offset from the DAC output and change the range?
This DAC has an output range of 1-3 volts. Here's the datasheet:
Datasheet
I'm getting pulses with different amplitudes, frequencies, duty cycles and widths varying from 0.2 ms to 2 s from the DAC. ...
1
vote
3answers
493 views
Inherent DC Bias in ADC sampling
I was just simulating the quantization behavior of ADCs of different bits, on data sampled by a 24-bit ADC. What I noticed that as we go towards ADCs with less bits a DC bias in the signal becomes ...
0
votes
1answer
3k views
Op Amp as a simple switch
I want to build a little voltage switch that switches on a buzzer and a relay when a certain voltage is reached. Please have a look at the schematic.
I use a trim potentiometer to set up the switch ...
0
votes
1answer
268 views
Resistor values for OpAmp circuit with dc offset applied to inverting pin
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\newcommand{\rth}{R_{TH}}
\newcommand{\vth}{V_{TH}}
\newcommand{\rf}{R_{F}}
$$
Asked this in the math stack exchange, who recommended asking here instead.
I'm stumped (hence posting here!) with ...
0
votes
1answer
105 views
What is a good way to add a programable offset to a diffential signal?
I have an AC coupled, ~10 MHz to 1 GHz, differential signal, with a programmable gain, coming from a detector. The signal contain pulses, and the DC-balance is poor but constant (even if my hand ...
1
vote
0answers
763 views
Audio DC Offset
I want to make an audio processing device using a Teensy and I want to run an analog signal into it. My background is in audio programming, so electronic circuits are new to me. I realise audio is an ...
2
votes
1answer
119 views
Opamp DC offset Question
Just need some help understanding what's happening in removing the DC offset from two band-pass filters.
VG has a value of 4.5V. When I added in the virtual ground the circuit had an offset of 4.5V ...
1
vote
1answer
130 views
Unwanted constant offset in ADC reading
I am using an AD7323 12bit+sign 4-channel ADC an on a custom Arduino shield.
I drive it with 12V from a power supply and -12V created using an ICL7662 IC. VCC is 5V from the Arduino.
The ADC is used ...
-3
votes
1answer
4k views
How to add dc offset and gain to a given signal
Before I start, I just want to mention that I am a premed student. However, I want to build a DIY amp for my headphones since my computer can't properly drive them so I decided to take an electronics ...
0
votes
4answers
15k views
Adding DC offset to a given input
let me start off by saying I am a computer science student so I'm not familiar with electronics whatsoever. Anyway, I am faced with this problem:
I am given some input (say, a sine wave) centered on ...
0
votes
3answers
3k views
Ideal integrator op-amp DC offset at output?
i have a question with this ideal op-amp integrator circuit
where R=1k and C=1uF. Then i put a 50mV 100Hz square wave at the input and get the following response, which is what i expected and ...
3
votes
3answers
872 views
Offsetting a differential amplifier to remove the need for a dual supply
I'm developing two similar circuits that will enable me to differentiate the X and Y coordinates from a segmented photo-diode (Four segments). These coordinates will be dependent upon the position of ...
0
votes
2answers
1k views
OP-AMP DC offset compensation
I do not know how to compensate the DC-offset caused by the Input bias current.
simulate this circuit – Schematic created using CircuitLab
How to compensate the input current bias DC offset? ...
