Sensor Definition and 392 Threads

Hello, We are doing a lab studying terminal velocity. Unfortunately we do not have a motion sensor, so we are dropping coffee filters at a certain height (both scrunched and flat- while increasing their numbers), and noting their final speeds. The thing I don't quite understand is whether...

Anyone has got an idea about a sound sensor ( that is really sensitive !) , i.e., can sense the sound levels of 20-25 db to convert them to electrical signals...or atleast how to make such a sensitive sensor...

Hi! I am using this hall sensor http://docs-europe.electrocomponents.com/webdocs/0d88/0900766b80d88153.pdf i got 2 problems: 1. When i vary the magnetic field, the hall sensor is acting like digital, i mean, it showing either high value or low value... Its not varying linearly as the distance...

I want to build my own circuit sensor. I opened the digital scale.I built the circuit on breadboard.The sensor is silverish color in the picture. I have completed my circuit on breadboard but don't know how will this sensor work. Can someone tell me what is the mechanism of this specific...

I understand the role of an image sensor is to convert incoming light into electrical charge (by splitting the light into RGB values and then measuring the intensities of each), but how does this occur? I know the answer is very basic (the sort of sensors I'm talking about are CCDs and CMOS)...

Hello, I’m currently working on a project in which I need to know the weight distribution in the four tires of a car at all times. I was thinking to install strain gauges somewhere in the chassis, or displacement sensors by the suspension. However I don’t feel these methods will give me...

I helped my colleagues simulate inductance of vr crank sensor in Maxwell but my simulation result is quite different compared to the test one. Our sensor is quite simple, just a piece of permenant magnet, a piece of flux concentrator made of normal steel, and one copper coil hooked outside of...

Output resistance problem Homework Statement Hi, I am not getting the answers right, and I think I misunderstand the logic behind this circuit. http://imageshack.us/photo/my-images/577/screenshotfvm.png/ Homework Equations I know that the equation of Vin is Vin=(VsRin)/(Rs+Rin) and...

I'm working on a sensor signal conditioning circuit. The sensor output has a 2.5V DC bias with a peak-to-peak voltage swing of about 50mV. The signal output is put through a demodulator and then filter (LPF) to obtain a DC voltage proportional to the out of the sensor. The problem is I need to...

Hey guys - I've been looking to find an oxygen sensor that fits certain criteria. I've been looking through oxygen sensors on Google and I can't really figure out what kinds of inexpensive oxygen sensors are available that aren't meant to go inside car exhausts. I would really appreciate it if...

I need to read out the temperature of ZrO2 devices which rotate along their axis between 10-100 kHz by using dry compressed air. The external diameters of each device are: 1mm, 3mm or 4mm, and they rotate inside a special stator The actual rotation speed is read by an optical fiber...

Hi, I'm working on an idea and i need some guidance say i have a wire loop of a single wire (not solenoid) the area of the loop is about 1-2 cm^2 now say i change the area of the loop slightly by about 0.1%-0.01% could i measure with today's electronics this slight change of L thanks in...

Hi guys, I'm trying to design a brushless motor for an EV with temperature sensing for both the copper coils in the stator and the permanent magnets in the rotor, but I'm not sure how to add a temperature sensor on the neodymium magnets in the rotor. Wouldn't the high levels of varying...

Hi There, I'm looking for ideas on finding the position of objects (such as a hand or foot) placed in a tank. Without using a camera soultion, I think the use of something like a minature laser range finder or IR proximity sensor. My problem is that I need to find distances between 5cm (min...

Hi, What kind of sensor can be used for finding the relative position between 2 satellites? Thanks.

So I've been looking at magnetic sensor datasheets and I see the sensitivity is usually listed in units of mV/V/gauss. What does this mean? Let's say I need to sense changes in a magnetic field that usually ranges from about 10 gauss ( 1 mT ) to about 130 gauss ( 13 mT ). And I need to be able...

Both Seismic sensors and accelerometers are used for sensing vibration. Then what is the difference between them?

I am just confuse about zinc oxide being a gas sensor. What I am implying is that why it can detect gases such as methane and C2H5OH? What are the properties of ZnO as a gas sensor?and what is the physics behind this gas detection?

I've developed a new concept called "Ambient Light Ignoring Infrared Active Distance Sensor". It consists of a transmitter with an infrared LED which uses a traditional LM555 timer to oscillate a frequency of 5kHz and a modified receiver which consists of a common emitter setup, NPN...

hi everybody. a friend of mine needs to make an ammonia sensor from the mq137 sensor, but we couldn't find a circuit anywhere. can any of you guys help us out? we need it to trigger a relay when a preset threshold is reached. thanks in advance!

Hi. I've just started working with the MPR121 capacitive sensor (at the moment I'm working with the MPR121 breakout board sold by sparkfun) for an application that involves detecting a toolhead's distance above a work surface. It's not a problem to ground part of the tool head and some initial...

Hi, I need a little help trying to determine the possibility of incorporating touch and motion sensor technology in material like rubber, plastic or glass. My question is as follows: Is it possible to incorporate touch and motion sensor technology in material like rubber, plastic or glass...

I have a simple home built pulse sensor that uses light from an LED to measure the opacity of my skin. As my heart beats the opacity of my skin goes up an down in a saw tooth like pattern. The frequency of this wave is my heat beat. The frequency is easy enough to find manually (by counting the...

I'm trying to build a non-contact displacement sensor, sensitive to motion in the micrometer to millimeter range, for a research project. My two best choices are a self-mixing laser interferometer and a capacitive displacement sensor. Has anyone had enough experience with these types of sensors...

Hi, I am trying to measure the center deflection of a simply supported beam with a capacitive sensor. The beam's surface that is the sensor's target is originally flat. After applying equal forces on the two edges of the beam, its center curves upwards (away from the capacitive sensor) thus...

I am doing a project, where I am measuring the tension exerted by different guitar strings from different sets for the classical guitar. I have a Vernier dual force sensor to do it, so the method would be just attaching one end of the guitar string to the Vernier sensor, while the other end...

Hi all, We're working on a project where we try to calculate the distance traveled by a mobile phone which is thrown in the air (only vertical movement, not horizontal). We use the accelerometer to get the acceleration in the x-, y-, and z-axis. Now we try to fix the error caused by the...

Andy has elaborated about photo sensors https://www.physicsforums.com/showpost.php?p=3091595&postcount=2. The essential part: This gives the impression that a lot is wasted. If a "red" photon happens to hit a blue filter, it's lost. So every "pixel" containing two green and a red and a blue...

Hello! So, pet project. Basically, I'd like to be able to monitor the distance between two moving points, with distances varying from 0-2m or so, with a resolution of at least 5cm or so. (The actual application is to measure the distance between a person's feet while moving, running, jumping...

Homework Statement A sensor is at rest in a fuel tank , it is at a depth of 0.34m and the fuel has a specific gravity of 0.7 . Calculate the pressure experienced by the sensor ? Homework Equations I guess Pressure = force/area The Attempt at a Solution I considered gravity as...

I was reading this journal on FO-PPR sensor and had a doubt. Couldn't exactly google for an answer as it was unclear. "Integration of fiber optic-particle plasmon resonance biosensor with microfluidic chip" by a group of scientists. I have attached the pdf. Under the section "Preparation of...

Hi, I am currently designing a stabilisation device for use in water. The general idea is using an inertial motion sensor to detect the orientation and propellors to correct it. I have very little knowledge in this area and was wondering whether I can use a phidget to achieve a wireless feedback...

Homework Statement I am trying to figure out how this ckt works. But no idea, where to even begin. see attachment tp.png Homework Equations The Attempt at a Solution Q1 is diode connected. The Vbe temperature dependence is amplified to indicate the temperature. -2mV/ deg C Gain...

Hi all, I am trying to connect a Parallax PIR motion sensor to a mini-usb cable. The PIR sensor has three pins: GND (negative), VCC (positive) and OUT. The USB cable has four connections: GND, VCC and the DATA (+ and -). I am able to power up the sensor and see a voltage spike when...

Hi, I was trying to measure DC link current on a switched mode power supply when I came across a quirk of my circuit. I'm using an LEM HX 03-p SP2 hall effect current transducer to measure current. I couple the output node of my current transducer to ground via a 2KΩ resistor. The device's...

Hello I'm designing a project and i need a sensor that can detect human motion.I would like to detect the output signal of this sensor by searching it via laptop or mobile phone as if they are searching for a wifi signal. I would like to know if such sensor is available or should i build a...

I feel really stupid for asking this.. but how does this sensor work? I'm not really good at electronics. What I mean is, if I have air flow through a pipe, how would I use this, through the small pipe that comes out the top? Or maybe put it inside the tube? Or is this an atmospheric pressure...

Hi. I have a few questions about sensor specifications and its implementation in a Kalman Filter and simulation of gyroscope/accelerometer output. Abbreviation used: d - discrete c - continuous Q1: From book: Aided Navigation - Farrell (you don't need the book to understand the...

Dear PFs I am facing a problem with finding a good Hall-effect magnetic flux sensor which should be fixed in the top of a probe working in a very intense magnetic field. The probe must be aligned to a certain degree with respect to the direction of the main field. The requested alignement...

Hi Guys, I'm currently doing my final year project which my title is to design a remote sensor to monitor home electrical apparatus by using hall effect sensor. I've build a basic circuit and amplifier to test my hall effect sensor ic ( linear) with a magnet. Everything works fine and now...

Hi friends, I'm an outsider with a management science background looking for a solution into a technical matter I can't resolve by scouring the net. I am working on an academic project that will allow me to track multiple pressure or force points and have that information transmitted...

hye guys... i need to do some design which need me to use S beam load cell as gravity sensor...anyone have ideas about my project?

I don't know about you people, but I often loose my milk, because it boils and spills out, just when I am not looking at it. :) Is it possible to alarm when it is just about to boil, by sensing its temperature? My concern is, is temperature a reliable indicator (impurities, varying degree of...

I am beginning a new project in which I plan on using the distance between my hands as a measurement. Being new to electrical engineering, I am not quite sure of what type of sensor to use to accomplish this. I would the sensor in one hand to only pick up the receiver in the other hand, not just...

Hello, I'm not an electrical engineering student so please bare with me... anyways if let's say you swallow a pill containing a piezoelectric sensor to measure adsorption of a molecule in the stomach how can you detect the changes in frequency? if there is no "physical" electrical connections...

I'm an old digital guy working on a little analog oscillator project so I'm a bit in over my head. The objective is to detect alloy deviations in samples of aluminum scrap: a very simple go/no-go detector I've cobbled together an inductive meter design using a dual op-amp sine wave...

Here's the circuit- It isn't clear to me which part of this circuit makes the voltage divider and also it doesn't show where the voltage output is on the circuit. Can someone tell me those two things please. Also I don't understand why voltage increases as resistance increases in the LDR...

Hello, I'm looking for a distance sensor for range of 100 meters (neutral surface). The sensor should be small (15cm^3). Do you have any recommendations? thanks Nir

Hi, I'd like to know how it's possible to calculate the altitude of a satellite using some kind sensor. I know that near-space(28~30km) you can still read a very low pressure so I can calculate the altitude using pressure. But and after this? I read that you can use gravity so, can I use...

http://farm7.static.flickr.com/6125/6203213456_7daabe9662.jpg" This is my first post and I've never been here so I'm not sure this is where i should post my question, but if I'm wrong, pls correct me. This force sensor is to load my truck ontop of that shaft to determine it's drag force...