Questions tagged [sensing]

Related to sensors and sensor systems

Filter by
Sorted by
Tagged with
0
votes
0answers
35 views

Spectrum Sensing

I am trying to find the maximum range of a directional antenna whose beamwidth can be varied. The goal is to understand if a particular (x,y) user lies within the antenna. The distance between the ...
1
vote
1answer
113 views

How to detect which pins on a pin display are touched using capacitive sensing

I'm working on a project to apply touch sensitivity to a modified pin display (30x30). The goal is to allow someone to interact with the display through their fingers and ideally touch. We initially ...
0
votes
0answers
79 views

4N35 opto isolator with ESP32

I had an old Arduino setup where I used this chip to interface with another circuit which had some LEDs. The goal of the project was to signal the Arduino if the external circuit turned an LED on. In ...
0
votes
1answer
57 views

Microwave detection circuit verification

I want to develop a circuit which can detect electromagnetic waves (radio wave, microwaves.) This circuit will just act as a tamper detect and not physically measure/compute the radiation. I have ...
2
votes
4answers
200 views

Detecting chess pieces on the board

First of all, I have absolutely no experience in electrical engineering, so bear with me. I want to build a chess set in which it can recognize what piece is on which square. Initially, I thought I ...
0
votes
1answer
54 views

Verifying electric brake current with opto-isolated feedback

I would like to find a way to sense (or detect) current through an opto-coupler. This opto is used to power an electromagnetic brake, but depending on the type of brake the current through it can ...
0
votes
1answer
27 views

Switched Mono jack + battery: Make circuit when plugged in

I would like to replicate the functionality inside the Ampoids guitar amp (9v battery) in which the circuit is turned on only when you plugin a male 6.3mm mono jack to it I believe that the most ...
1
vote
1answer
71 views

Could a time-domain reflectometer, with no access to earth-ground, indicate if a long-wire is attached to the end of a long steel beam?

Without using any other wiring, optics, RF, sound, or vibration, I need to know if a 100 meter length of electrical wire is attached to the end of a 50 meter long steel beam. I only have physical ...
0
votes
1answer
116 views

Isolated AC line voltage monitoring circuit

I found this https://www.edn.com/isolated-circuit-monitors-ac-line/ circuit in my quest for a low cost isolated AC line voltage monitor and constructed it. On testing however, I am not getting the ...
2
votes
0answers
50 views

Creating battery pack with biased thermistor resistor network. How to ground if sensing externally

I designed a battery pack board for a customer that uses a multi-cell low-side (NMOS) protection IC. The protection includes OV, UV, OC, and OT/UT protection for the pack. The Overtemp and Undertemp ...
0
votes
1answer
97 views

Reading data from PCB using LED light

I have a PCB that controls some doors and gates at a facility. I need to determine the status of said doors/gates. There are no I/O ports at the PCB to read from, and soldering some probes to it is ...
-4
votes
2answers
224 views

What are the two sensors doing in the automatic bread production line? [closed]

I want to know what is the name of these 2 sensors and what function they perform Some of you were complaining about the picture quality. It is the highest quality image I can get. Also these sensors ...
0
votes
1answer
50 views

Power supply sensing circuit/Mosfet

I am with EE background and recently I had question in interview regarding “How to sense/know when device needs power?”. So, basically I had a good interview on different topics and one of them was ...
0
votes
1answer
136 views

Has someone here ever made a DIY LiDar from scratch that can 3D scan? If yes, can you give an explanation regarding the process of doing so? [closed]

We've been tasked to create a LiDar system from scratch (we're not allowed to use modules like TFMini and vl53l0x, we have to make it from scratch) that can output 3D projections. So far we've been ...
0
votes
1answer
74 views

Predicting and Evaluating Connector Performance in a Capacitive Sensing Application

I have built a capacitance measuring system using the Texas Instruments FDC2214EVM evaluation module. The system is used to monitor the location of the user's hand in an enclosed space, where ...
0
votes
2answers
90 views

Chosing microcontroller for a sensing project

I am upon chosing a microcontroller for a PCB board project. MCU collects data from capacitance to digital converter (from a capacitance sensor) via I2C and I would like to pass that data to a host PC ...
0
votes
0answers
29 views

termination of a parallel wire differential transmission line as delay line on variable dielectric constant medium

Well this has quite a long title, lets explain the situation I'm currently working on the design of a sensor to measure the dielectric permittivity of a liquid medium, the idea is to use a ring ...
2
votes
2answers
1k views

HCPL3700 - 220V sensing circuit

I want to use HCPL3700 optocoupler for sensing 220V (line). I design a circuit but I want to ask some questions. HCPL3700 is an open-collector output so I pull-up Vout. In AC voltage sensing some ...
3
votes
4answers
264 views

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 ...
1
vote
1answer
159 views

Cheap soldering flux causing QRE1113 circuit not working

Edit (months later): Coming across this silly question I posted months ago, I want to talk about what caused my problem actually. My cheap soldering flux did that. After being heated up, it would flow ...
0
votes
1answer
31 views

How are individual mutual capacitance signal read out from a touch screen?

If I understand this correctly, on a touch screen, you have a a grid based system where the rows and columns are either driving or receiving. When you touch the screen a mutual capacitance arises ...
1
vote
1answer
164 views

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 (...
0
votes
2answers
184 views

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 ...
1
vote
2answers
218 views

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 ...
0
votes
2answers
361 views

Differential Opamp Strange Behavior

I have no answer for this strange opamp behavior. The circuit shown is from a typical nonisolated ,Non grid-tie inverter product (imagine H bridge Inverter). which has a common -ve high power circuit ...
1
vote
1answer
336 views

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 ...
0
votes
1answer
280 views

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 ...
0
votes
3answers
248 views

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 ...
1
vote
1answer
41 views

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 ...
3
votes
1answer
17k views

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 ...
0
votes
2answers
1k views

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. ...
1
vote
0answers
127 views

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 ...
0
votes
5answers
695 views

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 ...
0
votes
1answer
612 views

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 ...
1
vote
1answer
138 views

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 ...
1
vote
2answers
172 views

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 ...
11
votes
5answers
3k views

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 ...
2
votes
3answers
2k views

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 ...
1
vote
5answers
2k views

How to improve resolution and presicion of sensor reading?

I'm trying to measure temperature with an arduino uno and a LM335 temperature sensor. The LM335 can provide differences in temperature between -40C to 100 with a resolution of 10mV. I read the sensor ...
0
votes
0answers
233 views

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 ...
0
votes
2answers
3k views

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 ...
64
votes
6answers
11k views

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 ...
1
vote
1answer
288 views

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 ...
1
vote
1answer
467 views

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 ...
1
vote
1answer
55 views

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 ...
1
vote
2answers
2k views

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 ...
-1
votes
3answers
234 views

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 ...
5
votes
1answer
605 views

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 ...
0
votes
2answers
284 views

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 ...
2
votes
3answers
85 views

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 ...