Questions tagged [sensing]
Related to sensors and sensor systems
110 questions
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Check for live high voltage shielded three phase conductor
We would like to know if a shielded high voltage cable 8000V AC, 3 phases, is "live". Whether there is current flowing or not.
Ideally we design a little device that's strapped around the cable (...
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Why I got a minus output value?
When I simulate the circuit on (OrCad) I got an output voltage between (0 to 1) V changing with temperature .
but when I connect the circuit I got the output voltage = -1.85 in minus and different ...
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Controlling an output based on level of AC signal
This is my first post on this StackExchange after years of lurking, so please be gentle!
I would like to be able to enable an output (for example an LED) based upon an AC voltage from a split-core ...
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Differential Opamp Strange Behavior
I have no answer for this strange opamp behavior. The circuit shown is from a typical non-isolated, non grid-tie inverter product (imagine H bridge inverter), which has a common -Ve high power circuit ...
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Sense 230V - current
Brief sum up (you can go directly to the end if you already read the sum up in the other question)
For a home project I'm making a controller to drive a two-direction 230V motor. For those unfamiliar ...
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Sense 230V - voltage
Brief sum up (you can go directly to the end if you already read the sum up in the other question)
For a home project I'm making a controller to drive a two-direction 230V motor. For those unfamiliar ...
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470
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Automotive accelerometer calibration
I would like to design a device which measures acceleration, yaw, pitch and roll for motorsport/automotive application. I plan on using an analog accelerometer, to provide better bandwidth and low ...
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Is there such thing as an EMG sensor which doesn't use electrodes?
In a traditional EMG the user is required to clean the target area with alcohol, then apply some gel, and finally stick on an electrode.
I'm looking for some sensor that can read the same muscle ...
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AC Optocoupler for 230V line detection
I am trying to detect line voltage (230V AC, if the supply is ON/OFF) by a microcontroller with the help of an AC optocoupler. The optocouplers I have evaluated are PC814, H11AA1 and SFH620A-3, out of ...
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220 VAC detection using Optocoupler
I tried to detect 220V AC in my microcontroller using SFH620A-3 with series resistance of 440K (2 x 220K, 1/4 watts SMD type), a 1uF at the output to smoothen the pulse and every works as expected. ...
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MOV wear sensing
How would one go about to implement accurate sensing of metal oxide varistor wear level?
Even cheapo surge protects come with a LED to indicate protection status, but I presume this is not based on ...
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Isolated mains sensor
I’m building a mains sensor that should be able to operate safely at a voltage of up to 650VAC. I’ve already built one before, that operated with 130VAC, which I successfully monitored with a MCU, and ...
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Ion-current sensing in ignition coils
Variety of IC engine manufacturers have eliminated acoustic knock sensors from recent designs. Those got replaced with Ion current sensing circuitry (feedback from the spark-plug).
In parallel, SMART ...
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Positive and Negative Sense Circuit. How/why does this work?
I am trying to build a centre-off model railway controller, no reversing switch. I am working on the overload/short detection part of the circuit based on sensing the voltage across a 0R68 resistor. I ...
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vibration sensing circuit doing so great
I have attempted this diagram from here:
with one modification - instead of the 4093 circuit ( comparator+inverter+hysteresis gates) I have used a HC14 (inverter+hysteresis gates). Can this be why i ...
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What is purpose of an Undervoltage Sensing Circuit?
I am wondering what is the purpose of an IC such as the MC34064. Is it just to ensure a reset of microcontrollers upon power up or are there other reasons? I used to make a simple transistor switching ...
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Alternatives for EMG muscle sensors?
I would like to measure muscle tension with a sensor. When I'm sleeping sometimes a shoulder muscle cramps and I would like to make something (for example with an Arduino board) to wake me up. The ...
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How to improve resolution and precision of sensor reading?
I'm trying to measure temperature with an Arduino Uno and an LM335 temperature sensor.
The LM335 can provide differences in temperature between -40C to 100 with a resolution of 10mV. I read the sensor ...
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Sensing AC voltage
In a project I'm working on (Totem pole PFC) I need to sense the input AC voltage, scale it down, rectifing it/adding an offset and then send to the ADC of the digital controller to use in the control ...
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AC voltage sensing circuit
In a project I'm working on, I am designing a Totem pole PFC, and for the controller (using a digital controller) I need to sens the input voltage, which is an ACvoltage and feed it to the ADC of the ...
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What makes smartphones tilt-sensitive? Will they retain this ability in zero-gravity conditions?
Most smartphones are tilt-sensitive, but what device makes this possible? Additionally, how does it (and the sensors associated with it) work?
Also, since the working of these sensors seem, almost ...
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Sensing high differential voltages using operational amplifiers
Is there any solution to sense high differential voltages using operational amplifiers (without using resistive voltage divider) ?
The input voltage range is [-30, 80] Volts.
I've searched on all ...
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Metal detecting using a small inductance
I have a coil with approximate indutance of 15uH used to detect metal through changes in inductance. I want to use an op amp or 555 to oscillate with frequency based on the inductance. However this ...
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Harmonic compensation due to a non-linear load
I am doing a project on harmonic compensation due to non linear loads. My current at the source is non-sinusoidal due to non linear load. The current contains harmonics and i am using ACS712 current ...
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How does this capacitive soil moisture sensor work?
I’m trying to figure out how the following soil moisture sensor works.
It’s obviously a capacitive sensor where the capacitance changes when the soil moisture varies.
However, as you can see, the ...
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3
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current sensing board/adapter (low current)
I'm trying to find a well designed current sensing board which is intended to be used with an oscilloscope.
The closest thing i found is the ucurrent which is meant for multimeters, low cost ...
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Do current / power monitoring ICs (e.g. INA219) allow frequent re-reading?
I'm looking at the datasheet for the Texas Instruments INA219 and on page 20 it shows a table for "Shunt ADC Resolution/Averaging", which describes the ADC resolution and averaging settings which can ...
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How to display voltage on OLED? [closed]
The basic idea is to make an OLED voltage meter.
I idealy want to use as little parts as possible.
If my understanding is correct I would need a voltage sensing circuit which would give feedback to a ...
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3
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92
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Sensor to rapidly sample light intensity of a small area at a distance?
I'm looking for a sensor or method of rapidly sensing light intensity of a 1-inch x 1-inch square of a LCD monitor at a distance of 1-1.5 feet away. Does anyone know if such a thing exists, or has ...
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How can i sense if a circuit is open on 2 wires and if so, close the circuit on another 2 wires?
I have a 4 wheeler that i converted from a mechanical locking differential to an electric one. the mechanical one had a 2 wire spring loaded switch that as the mechanism rotated it pushed the pin in ...
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Flame sensing using flame rod and short circuit identification
I am sensing a flame using a flame rod.
I am using 12V AC at the input and at the output flame sensing circuit which is made of opamp, some resistors and capacitors.
I get 1.6-2.4V when there is a ...
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Measuring a potentiometer with noisy power
I need to measure a potentiometer where the voltage supplied is very noisy and cannot be filtered.
I run into this a lot in my work, but currently I'm trying to measure a steering angle potentiometer ...
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Detecting motor stall with lm311
I have 9v DC motor that I want to use to lock a door. Control is achieved using an esp8266 board. The esp8266 also switches the direction of rotation via an H bridge. So far, so good..
Now I want to ...
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Measure current in power suppy [closed]
I have a power supply which I ordered online for 100 amps. I thought it will be digital but its an old fashioned type. I want to build the current sensing circuit to find out how much current is ...
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Capacitive touch insulation problem?
I have an "U" shaped metal profile that is 2 meters long each side is 1.5 cm.
It is sprayed with acrilic color. and i want to use it as indirect light profile/enclosure for a 12v Led strip.
While ...
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Determining the radius/length of an IMU on a rotating stick [closed]
So I can't really wrap my head around this problem.
I have an Inertial Measurement Unit (IMU consisting of an accelerometer and a gyroscope) mounted to a stick which can rotate from a fixed position ...
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C4D capacitively coupled electrode sensing - circuit simplification
I am trying to make a detector to pick up small changes in capacitance. Basically both electrodes have a common ground and are closely spaced. One is driven by oscillator at 0.1-1MHz and the other one ...
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Is it possible to "trace" a hall effect sensor on a PCB?
To my knowledge, a hall effect sensor is just a soft-cored hooped metal (iron?) with some wire wrapped around it a precise number of turns. This surrounds another wire that you wish to measure the ...
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Voltage sensing using Arduino with and without common reference
I wish to make a voltage sensing circuit (range -15V to +15V) using an Arduino's ADC. The problem is that since this circuit will be part of a much larger circuit in which the Arduino is performing ...
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Sensing power supply - sensing after the on/off switch
I have a sensing power supply powering a custom build LED light for video. There is an on/off switch after the sensing lines and everything works well. The setup looks like this:
However I'd like to ...
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Current sensing with AD623
I want to measure current that flows from a several kΩ load with source voltage sweeps from 0-200V. I want to measure possible energy losses, so I need both low and high side sensing. Setup is ...
user86045
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Choosing a Shunt Resistor for Low Current Applications
Is it possible to use a shunt monitor to measure current for low values(10 mA-100mA) and if is it possible, should I use low resistive values like in most of the power circuit applications? I know ...
user86045
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Detect if input voltage is 110V or 230V signal
I'm building a small electronic project that will measure the power consumption of a device and send this back to Arduino or ESP2866.
I've figured out how to measure the current that goes trough a ...
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Lm35 arduino and battery
I am doing a project where I need to measure temperature using lm35. I am using arduino's analog A0 to measure, I light up extra LED on an other pin while measuring. Suddenly the alarm triggers. I ...
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how to design a differential op-amp for sensing a ac current?
I tried to design a simple electronic load, but I would like to amplify the the voltage across the sensing resistor with gain of 20. Then I can apply a sine wave reference to have a current between 0-...
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Determining which power supply is connected to our circuit?
I am designing a small dongle that will have features either enabled or disabled as a function of the supply voltage. I want the device to be low-power and run, for the most part, off a 3V coin-cell ...
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Methods/sensors for making a "smart floor" to detect human presence via floor?
I am looking into making a "smart floor" that can detect when someone steps down onto it. I have done some research and found that the most commonly used sensors are 1) Pressure sensitive floor tiles ...
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TA12L-100 current sensor max current
I want to buy this current sensor from eBay. I couldn't find how it works, but I presume it works like the other ones through induction. On many sites it says it has a maximum current of 5 amps, but I'...
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What Difference between sensors and intelligent sensors [closed]
I was studying about sensors. I'm confused about the diffence between Sensors and Intelligent Sensors. Both seem same to me !!
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Current, Voltage, and Power Sensing for 115 V AC Circuits
I am trying to sense voltage, current, and power with an Arduino (Due) for monitoring and diagnostic applications. To get reasonably good input (better than Kill-A-Watt), I have designed an AC sensing ...
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