Electrical Engineering Stack Exchange
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Questions tagged [sensing]

Related to sensors and sensor systems

As the term itself implies, sensing refers to the capacity of the sensors or a system that contains sensors, to "sense" (meaning, detect and/or interpret) physical phenomena and/or events.

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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 certainly, based on the presence of an external…
paracetamol
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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 circuit (with RC) for resetting microcontrollers…
GeneCode
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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 intensity of passing current. The coil has a…
Mike Armstrong
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Sensing AC high voltage to microcontroller

I'd like to sense if I have AC 220V 50HZ available, and convert it to some logical level. I made such circuit, will it work? I use C1 as a resistor. Any recommendations what can be improved? UPDATE: Thanks for the great help. I choose Russel's…
HardQuestions
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Find out value of pF capacitors

I'm looking for a way to calculate value of capacitors of picofarad (pF) range. The thing is when I use a RLC meter, it looks like the device is limited to high ranges of pF to nF and so I can not measure value of for example 1pF. I used this…
Ala Shafighnia
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Recommended Layout for Parallel Current Sensing Resistors

I'm working with 12V DC systems and high currents (up to ~40A). In order to meet the wattage and price requirements for my design, I'm using two parallel sense resistors. The IC I'm using for sensing is (PN: PAC1710-1-AIA-TR), though this question…
Jack
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How to sense wind direction - low cost, low power

I need low cost wind direction sensor. Requirements (edited) low power low cost ($5 or less) wide temperature and humidity range (it will be part of weather station) at least 5 degrees acurracy and resolution response time - it may be few seconds,…
Kamil
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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 be applied, along with their conversion…
Polynomial
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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 which I found SFH620A-3 to be more efficient…
Zac
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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 with the (onboard) AVR ADC which is 10-bit. I…
John Am
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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 that I need low resistance because it shouldn't…
user86045
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How does this capacitance measurement op-amp circuit work?

I'm studying this scientific paper where a capacitance measurement is done with the circuit shown at page 3. For simplicity I reported it here: A sinusoidal signal is applied at the input through a function generator. The goal is to measure the…
Idix
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Detect 230 volt main supply in a cheap and easy way

I need to detect by if one o more pumps are really connected to the 230 Volt main supply. Each pumps is activated by means of a triac isolated by a MOC3021. Arduino commands the optoisolators and I need to detect if really the triac has switched on…
daigs
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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 problem is to measure the muscle tension. A EMG…
Jot
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Op-amp use in voltage sensing

For voltage sensing, we use a resistor divider and then we always feed that value of the resistor divider to an op-amp and then the op-amp output is fed to a microcontroller. What exactly does the op-amp do in this case? Why can't we feed the output…
Alison
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