Questions tagged [precision]
Use this tag to indicate that the topic is related to achieving the highest precision for a circuit. Examples include using 1% resistors instead of 5% or 10%. This tag also can be used in relation to measuring precision in a finished circuit.
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Load regulation of constant current source
LM317HV data sheet provides following reference circuit for use as a "simple, fixed-current regulator" in section 9.2.9.
It also specifies typical load regulation of 0.1%. I don't think the ...
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Right transimpedence amplifier choice for input range
I have a device that produces a ±30 nA signal and I'd like to measure this to a 0.1 nA precision.
Since the currents are so low and I don't have much time to make mistakes, I am planning to use a TIA ...
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How to tell if a motor is slightly jammed?
I am trying to use a motor for an application that requires sensitive handling of playing cards (a card shuffler). The main objective in this case is not speed but control. The most important thing is ...
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What is more precise: using an op-amp or internal PGA of an ADC to amplify a low-voltage signal?
I'm wanting to current sense a 10A load with high precision. I'm planning to use a current shunt resistor and then amplify/filter this signal before sending it to an ADC. Which design flow is ...
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Voltage-controlled pulse width modulator (PWM) LTC6992 accuracy [closed]
I have to design a voltage sensor for sensing 4000 V highly precisely and for making the PWM. I was surveying the LTC6992. It is simple and quiet, easy to implement, but there is a problem with its ...
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Is there a specific definition for the tolerance value of a resistor?
Is there any authoritative definition for what the tolerance value of a resistor actually specifies, or is it just a de-facto common understanding, or are the details left up to individual ...
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Transimpedance amplifier maximum current resolution
Maybe this question is a bit too general but I don't seem to find any solution.
I want to build a current sensor for a current that ranges from 1uA to 1mA and needs resolutions of nearly 1pA.
I know ...
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Low noise virtual ground, voltage reference or LDO + op amp?
I'm doing some sensitive signal measurements in 1~10kHz range where I amplify and filter (multiple active stages) a small voltage signal by hundreds ~ thousands of times and then sample it. A negative,...
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I'd like to request a review/bashing of this circuit for a high precision soil moisture sensing and analysis device. Where did I go wrong?
Below you will find a buffet of questions and the schematic for my device. (Click on it and you will get the full-size image.) Please tear this up. I'm a self-taught novice putting together a high-...
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The most precise resistor
What is the most precise resistor available (measured in terms of ppm drift if
measurements are repeated over time)?
I just want a passive box with two terminals. The temperature will be kept between ...
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3 wire RTD configuration Wheatstone bridge Vs. Constant Current Source
I am trying to design a 3 wire RTD circuit. I've been looking into either a Wheatstone bridge or a constant current source with ratiometric measurements. I would like to know which is the better ...
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Negative pulse at NPN collector when base switches off and reverse-active mode behaves better at HF
I have a system that detects pulses amplitudes with a peak detector, the signal from which is then digitized with an ADC. Pulses can sometimes overlap, so I've decided to "zero" the peak ...
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Verifying the Measurement Precision of a Circuit
My aim is to build an electronic circuit that allows me to measure the relative precision of the energy of optical pulses in the order of 10^-6. The optical power of the laser pulses is measured with ...
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Ideas for measuring the position of a card in a bus (through hardware)
I am looking for ideas on how to detect the bus position of a module (PCB card) when they stack up.
I am designing a PCB module that is going to be controlled and connected to a carrier board. This ...
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Parallelizing op-amps for higher precision
Is there a known way to parallelize op-amps for higher precision?
Say, for example, I have a typical op-amp driving a MOSFET as a follower:
Now, for the sake of the argument, on average, the NMOS is ...
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Why does oscilloscope high-resolution mode for acquisition show inconsistent measurements?
Question: Why I get inconsistent measurements from scope specifically in high resolution mode,
i. At cold start higher values are obtained, as time passes measurements drift (gets lesser values)
ii. ...
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Mounting DIL8 package on SO8 footprint
As you might know, it is hard to get components these days. That's why we engineers have to get creative sometimes ;-)
The company I'm working for has a shortage of a Zener-type voltage reference ...
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Noise of a precision/active rectifier
I am trying to build a precision rectifier circuit to implement AM demodulation in a sensor signal chain.
For now I have calculated the sum RMS noise of the total signal chain except that of the ...
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Opamp output clamp
During power-up, U2A's voltage will be undefined. I would therefore like to clamp it with a relay. Additionally, U2A is buffering a voltage from a 20-bit DAC -- therefore I need to care about thermal ...
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Measure capacitors in parallel and series to increase precision?
I measure a capacitor \$C_1\$ with an instrument that has a tolerance of measurement \$\pm 5\%.\$ I do the same with another cap \$C_2\$. Then I put \$C_1\$ and \$C_2\$ in parallel (values add up) and ...
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Sigma-Delta differential ADC for PT100 without precision Iexc or Vexc
We are discussing a way to precisely measure PT100 (variable resistance) using a MSP430 with 24bit sigma-delta differential ADCs without having a precision source of current or voltage.
We came up ...
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Options for tracking upsets in very fine movements
I'm working on a small engraving device that sometimes hits a tougher part of the target material. Since the tip is very small and spins at a high speed, the engraver sometimes involuntarily slides ...
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Choosing transformer for precision power supply design [closed]
I am trying to figure out what specification transformer I need to design a linear precision power supply which has 3 channels operation with certain requirements.
All the 3 channels have total power ...
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Low spread high power laser
I am looking for a laser which can travel about 10 km through air from one end of a lake to another.
It needs to have a minimal spread, i.e. a small diameter spread over the 10 km - less than 10 cm ...
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Precision current source 1 nA circuit analysis
I couldn't find any detail explaining this circuit. How would I change it to make it operate between 1 uA to few microamps? Would change 10 Mohm to 10 kohm would greatly degrade the performance? I can ...
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MUX Pulldown resistor Questions
I have a precision application where I am demodulating two sine waves using an analog mux (ADG613) and then Low pass filter to measure it's amplitude.
The ADG613 is a 1:4 MUX made into a DPDT (chosen ...
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561
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creating a differential amplifier for low voltages (current shunt)
I'm trying to create a "precision" fully differential amplification stage, to measure uA on a 10R shunt, and mA on a 0.01R shunt. shunt resistance values are set at those values for burden ...
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Active voltage limit circuit
In my application there is a signal from 0-10V. The signal gets into 4 different OPAMPs with different gains which are supplied from +- 5V.
I would like to limit the input voltage to the OPAMP to 0-2....
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MEMS-FPI tunable filter
I've got to control a tunable filter on a MEMS-FPI C14273 IR sensor. It works by inputing a voltage on a range from 25 to 48 V, wich makes the lens move. It needs to be precise because if i go over ...
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How do I deal with Seebeck Effect while measuring resistance with 4-lead ohmmeter?
I'm trying to measure the DC resistance of an inductor I made out of AWG 11 wire.
From my calculations its impedance should be around 0.0012 ohm, and the ohmmeter measured precisely 0.0012 ohm.
But ...
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Is there a way to average resistors together to get a tighter overall resistance tolerance?
I have a very sensitive, kHz frequency level, application where I need two matched resistors of the same resistance better than 0.05%. Like maybe by one magnitude (0.005%).
I am basically needing to ...
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Op Amp Selection Help for Rail/ Rail IO
I am looking for an operational amplifier which will fit my requirements.
My circuit consists of two cascaded non-inverting amplifiers.I have a classical non-inverting setup.The minus pin of both ...
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Precision amplitude 600kHz square wave generator
I'm looking for a circuit that creates a precision amplitude square wave of 600kHz (50% duty cycle). The amplitude of the square wave needs to be 3Vpk-pk +/-10mV, but can be DC offset. The output of ...
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Input voltage drop in LM358 with "an improved precision rectifier circuit."
I found the input voltage drops around 2V drop (observed from oscilloscope) when I connect the ion mobility spectrometer (IMS) signal to the circuit "an improved precision rectifier circuit",...
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Floating point representation- Double precision
The difference between 201 and next larger double precision number is 2^P.
If IEEE double precision format is used then the value of P is _________?
-- I know how number is stored using double ...
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How can I make this Component Tester more accurate?
EDIT:
In the answer by Reroute (thank you, Reroute!), he references a very active 253 page EEVblog topic -- $20 LCR ESR Transistor checker project that probably includes exactly what I am seeking. I ...
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Op amp maximum input voltage
Many Precision Rectifier Single Supply Op Amp circuits feed the input AC waveform into the non-inverting (+) terminal of an op amp e.g. see this schematic:
Image source: Precision full-wave signal ...
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Bit growth handling for complex multiplier using Gauss' method
I'm trying to predict/handle the bit growth that occurs when implementing a complex multiplier using Gauss' method. I am looking to implement this multiplier in VHDL. The FPGA I use has a limited ...
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Arduino frequency measurement to 2 or 3 decimal places
I am in the process of building a Proton Precession Magnetometer to calculate the earths magnetic field strength by measuring the precession frequency of protons in distilled water. I am using an ...
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What are the effects we need to consider when transmitting extra low voltage (0.1 uV) signal over ~1m long cable?
What are the effects we need to consider when transmitting extra low voltage (0.1 uV) signal over about 1 meter of cable, either coaxial or shielded twisted pair ?
The source is low impedance (~5 ...
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high accuracy analog differential signal switching solutions to prevent distortion (relays?)
first let me define the application and circuit. the application of this is to sence currents ranging from 1nA to around 900mA. to accomplish this two resistors are used, a 10K for the nA range, and a ...
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mV variations even with a simple voltage divider
edit: After using a prototype pcb instead of breadboard, placing all possible electromagnetic sources away and unplugging all the equipment from the same line, my noise dropped 2 orders of magnitude. ...
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How does oversampling improve the measurement precision?
Regarding improving the precision of a measurement, I have heard that a measurement precision can be improved by filtering or oversampling.
When I think of filtering I can make sense because ...
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Confused with the effect number of decimals at the output of transducer
There is an ultrasonic device which measures and outputs both wind speed and direction and has a very long manual. But to keep it short and summarize, the accuracy and the resolution for the wind ...
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Use a precision opamps or instrumentation amplifier for load cell application
I'm making a low power weighing scale with good precision. I'm contemplating if it'll be better to build a instrumentation amplifier with discrete OPAMPs of LPV821 which is low power (Iq 650 nA), high ...
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Questions about LM741 in an ECG Circuit Schematic
I'm doing an ECG circuit in which I want to use LM741 for active filters and the Right Leg Driver. Basically I will change the LT1007 in the schematic I used for simulations above with LM741 in real ...
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Very high precision zero crossing detection
I have a setup that is equivalent to a guitar string with pickup, with signals of similar frequency range. I have a simple zero crossing detector with a comparator and then just count the interval ...
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How to obtain a high precision mV signal within a specific interval using a variable resistor?
I want to design a circuit which outputs a signal ranging from 0-70 mV using a variable resistor ranging from 80.51 Ohm - 183.05 Ohm and a supply voltage of 12 V. My idea so far has been to make a ...
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Should we use wheatstone bridges nowadays?
For measuring strain gauges, the Wheatstone bridge is the historical choice.
In a quarter Wheatstone brigde (\$350 \Omega \$ typically (?)), with a high input impedance amplifier, and some bridge ...
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Any way to build Analogue Multiplexers using MOSFETs or JFETs or BJTs
Here's my requirement:
I need an analogue switch that can do SPST/DPST/DPDT with very low On-Resistance (<10mOhms). There would be current flowing through this switch, albeit in the range of a <...
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