# Questions tagged [sensor]

Sensors convert a physical quantity (e.g. temperature, pressure) into an electrical signal.

3,212 questions
Filter by
Sorted by
Tagged with
36 views

### Generating Accurate Voltage-Temperature Sensor Equation for NTC RTD Inline-Liquid Temperature Sensor

I am currently trying to generate a curve of best fit for a voltage-temperature data points, where I am given a resistance-temperature table. (GE-1935 Inline-liquid Temperature Sensor: Amphenol). The ...
• 21
54 views

### Circuit for electrovalve using latching relays and two XKC-Y25 sensors

This is a follow-up of my previous post Latching relays for a water pump with two XKC-Y25 sensors. Here's the problem: I have an electrovalve that uses a 9 V DC latched solenoid, and I use it to fill ...
• 23
58 views

### How do I use the given voltage drop across $R_3$

I can't figure out how to solve this circuit if I use mesh I get these 3 equations what is the fourth equation?  24E3*i_1 - 12E3*(i_2+i_3) = 24-v_{52} \\ -12E3*i_1 + 25E3*i_2 - 10E3*...
82 views

### Connect multiple SDA and SCL on ESP32

I was wondering if you could set a GPIO pin of an ESP32 to be SDA or SCL even though the pin is not really intended for that. Here is the pinout of an ESP32 (Disregard the red rectangle): Source of ...
327 views

### P-MOSFET always conducting

I have this cirucit I designed for my PCB. It has a P-MOSFET (Si2347DS-T1-GE3) - https://www.vishay.com/docs/62827/si2347ds.pdf connected to two resistors and a capacitor. The idea is that with the ...
• 43
1 vote
62 views

### Help identifying I2C sensor from Propel Star Wars Drone

I have a sensor from a Propel Star Wars drone that I can't identify. The metal part of the sensor is marked with "A6103 040". I have tried various libraries and sensors, including BME280, ...
71 views

### Confusion with two types of differential signal coupling

I'm having difficulty to articulate the question. But perhaps I might get close to it by an example. I know that in differential signaling, both the signal and the receiving amplifier can be in ...
• 4,353
38 views

### How to read position sensor values more accurately for stpper control?

I am using Feather M4 express development board with DC Motor + Stepper FeatherWing and Ethernet FeatherWing stacked on it. The idea is to read the target position from the UDP from 0 t0 360 degrees ...
• 151
73 views

### Help understanding simple Arduino circuit from a datasheet example

I'm trying to use a water sensor in a new design, and I don't understand the example circuit that is given in the datasheet, even though it looks very very simple. I must be missing something. Any ...
28 views

### Impedance measurement using AD 5933

I hope this message finds you well. I am using the AD 5933 evaluation board for impedance measurement, The data sheet says it can measure the impedance up to 10M ohm. I am currently measuring the ...
75 views

• 187
66 views

### Detection system for specific material

I'm looking for some ideas on how to detect some kind of material/tag that can be electrically distinguished amongst organic material, wood and iron. Such material/tag should be possible to detect ...
56 views

### Connecting Two 24VDC Power Supplies

I have a system that has multiple different gas detection sensors and we are datalogging our readings onto a PLC. To power our sensors we are using a 10 A power supply and have everything grounded ...
50 views

### Suggest appropriate substitute for cable glands

I have a 3.3 mm cable coming from a sensor (3.3 V) and going to an instrument. I would not like any joints in the path in the form of connectors which could make problems for the sensor if the ...
• 99
1 vote
65 views

### Modelling an eddy current sensor

An eddy current sensor is modeled as an air core transformer with shorted secondary: simulate this circuit – Schematic created using CircuitLab According to Kirchoff's laws, the total voltages ...
1 vote
40 views

### Interfacing with 0..-2v Sensor using ADS1115

I'm designing a circuit to interface with a sensor that operates on a ±12VDC power supply and outputs a signal between 0 and -2V. I plan to use an ADS1115 ADC for reading this signal. Circuit Design: ...
• 41
373 views

### Design of very long serial signal systems

In the current case there is a single signal conductor, tens (hundreds?) of meters long, which serially connects door and window sensors for a whole building. The sensors are simplest possible ...
115 views

### Opamp dual package IC configuration

I have a question regarding the configuration of opamps for sensor signal amplification. I have a circuit with two sensors going through identical signal conditioning circuits (amplification and ...
• 93
40 views

### Temperature Sensor Auto

I'm trying to make a temperature sensor for a Golf MK2, with an LM3914N to light an LED bar with 10 LEDs and in the signal I'm using a voltage divider for R2 to be the temperature sensor that operates ...
29 views

### Measurement bias of Hall sensors with moving permanent magnets

I want to measure the magnetic flux density produced by a moving permanent magnet. In my case, the magnet would move left and right alternatively at speed of 10 mm/s, with a constant vertical distance ...
• 1
41 views

### Fingerprint sensor module communication (FPM383 R503)

I'm working on a fingerprint sensor that is known as FPM383. It is much like the well known R503 sensor. Their datasheet and serial communication manual are almost identical. I was trying to control ...
• 291
1 vote
74 views

### Which component is likely raising the temperature measurement on my BME680 sensor board?

I have integrated a BME680 temperature, pressure and humidity sensor on a PCB with NL27WZ17 Schmitt triggers (U3 & U4), a RT9193-33GB LDO regulator (U1) and a CM1224-04SO ESD diode (D2). I also ...
• 179
54 views

### How to connect E 610 piezo amplifier module to the piezo sensor for vibrations? [closed]

I have a piezo amplifier from PI instruments (model: E 610) that has to be connected to a cylindrical vibration sensor(piezo). I do not know how to make it vibrate using the amplifier and a function ...
54 views

### What is the difference between capacitive liquid level sensor and potentiometer liquid level sensor

I have a sensor I use to determine the level of water in my swimming pool. One person has told me it is a capacitive sensor and another said it works like a potentiometer. I would like to know what ...
• 215
37 views

### Closed loop Hall current sensor, is it possible to shift the result from negative output?

I am planning to use this closed loop Hall current sensor. Is it possible to use a unipolar power supply (ie. only +24V, no negative) and shift the result by not connecting RM to ground, but to a ...
• 583
23 views

### PIR sensor and its working

I have been designing a PIR sensor circuit for occupancy sensor. We have been facing problems like fault detections most of the time when we turn on air conditioning. There is also issues like the ...
37 views

### Can I Wire a Thermocouple Like a PT100 Sensor

I have an IoT multi-channel controller which can accept PT100 sensors (2-wire or 3-wire). I don't have any PT100 sensors, however I do have K-type thermocouple wire. Is there any way to wire in the ...
1 vote
52 views

### IR pulse sensor : signal stops after a few pulses

I'm trying to make a pulse sensor based on this tutorial: https://makezine.com/projects/ir-pulse-sensor/. I therefore reproduced this diagram by replacing the LM354s with MCP6002s and without ...
1 vote
47 views

### PIR Circuit Problem

I am using D203B model of PIR and I used the circuit that was suggested on its datasheet (first pic). I do not know what the problem is, as the output (pin the 8 and 14) of op-amp (LM324)is always on (...
• 27
51 views

### Methods For Reducing Output Voltage Of Pressure Sensor Into ADC

I am developing a data acquisition system that takes pressure readings from a pressure sensor. The pressure sensor is a bridge sensor which feeds into a differential ADC. The ADC has an input range of ...
• 167
19 views

### Wiring of buttons in solenoid and PIR sensor

Folks, have been working on the project and I'd appreciate any help with checking if everything wired correctly and if there's anything needs to be added or is redundant. Project is straightforward: ...
976 views

### Why is a Schmitt trigger useful for SPI?

I understand Schmitt triggers are a great way to convert a floating or noisy signal to either HIGH or LOW depending on a threshold. It is mentioned in other threads that a Schmitt trigger can help ...
• 179
1 vote
48 views

### Car side-mirror dimmer simulator circuit - DIY

Would like to make a simple car side-mirror simulator circuit. The side mirrors I installed (for better blind spot) do not have a dimmer circuit and I am getting LIN bus errors since the dimmer wires ...
• 11
81 views

### What could the strange noise in the images be due to? They appear to be composed of 8x8 squares, and many of them contain different patterns [closed]

The question may seem silly, but I am curious about the structure of images from a certain biomedical image dataset. If you enlarge the following image fragments, you can see that they consist of 8x8 ...
41 views

### Proximity sensor (3 Wire NPN or PNP) to RS-232

I do have 2 proximity sensors (level sensors) with 3 wire design. They offer to be PNP or NPN and I need to implement them into an RS-232. They are supplied by 24 VDC. Is there somewhat like a ...
36 views

### How to switch between 2 power levels for mq7 sensor

I am using mq7 sensor for my project.For this sensor according to the datasheet I need to continuously switch between 5 and 1.5 V input voltage to mq7 sensor. Since I am a beginner, wanted to know how ...
921 views

### How can I create 4-20 mA current souce

I have one op amp based circuit that converts 4-20 mA from current sensor into 5-9 V DC. Right now I don't have any such sensor to test this circuit. I want to create new circuit that produce 4-20 mA ...
928 views

### PT1000 drifts more than 100°C

I'm using a PT1000 and MAX31865 to measure the temperature inside a machine. Electronics (MAX31865 and MCU) are inside an isolated box. The PT1000 is outside and connected in two wire configuration (...
• 378
44 views

### Use digital sensor with USB to serial TTL converter?

I have a sensor (HC2A-S3A), which provides analog and digital output signals. The digital interface is UART (19200 baud, protocol RoASCII). Can I use a USB to Serial TTL Converter (chipset: FTDI ...
• 101
90 views

### Simulate hall voltage as a function of temperature in LTspice

I'm trying to simulate how temperature affects voltage sensitivity in my hall sensor from LTspice. How do I make use of this equation to get my correct output? Any feedback will help, thank you. I ...
• 21
44 views

### Is there a way to use multiple Ldr inside a darkness sensor?

im trying to make a darkness sensor with mulpiple LDRs, the idea is that if all the LDRs are in the dark, a light in a led strip is turn on, otherwise, the led strip stays off. I have manage to make ...
43 views

### A sensor's idle voltage is 1.1 V, and its triggered output voltage is 5 V. How can I condition the signal to be <0.2 V idle and ~2.5 V triggered?

I'm triggering a high speed camera with an analog chronometer tower that when un-triggered puts out 1.1 V. When an object passes through the tower, it briefly spikes to 5 V. I'm using an old camera ...
34 views

### Tie to VDDIO for I²C Interface

I want to communicate to a sensor that supports I2C and SPI. I want to use I2C and the datasheet says "Tie CS to VDDIO for I²C Interface", do I need to connect a resistor to limit the ...
42 views

### Flame Sensor Supply Voltage Range

I have this flame sensor module which I am going to use for a project. Upon closer inspection, I can see that the maximum supply voltage of the LM393 comparator IC used is 30V according to this ...
57 views

### Pinout and details for the ME4-H2 hydrogen sensor from Winsen

I have been trying to understand and use a hydrogen sensor from Winsen (ME4-H2). However, the datasheet is scarce in information about the pinouts and other details. The pins are called C, R, W and an ...
132 views

### MAX6675 SPI communication with PIC microcontroller

I'm using a PIC16F1832X to communicate with a MAX6675 thermocouple-to-digital converter. As I read the values of the temperature and the SSPBUF register, they are way too high; SSPBUF is 223. I assume ...
35 views

### Sleep mode of SGP40 sensor

I'm trying to develop a system which has a feature to monitor air quality using a SGP40. I want this board to be in sleep mode most of the time and only wake up if the sensor detects alarming ...
• 15
1 vote
138 views

### How to introduce a PIR motion sensor and/or timer into my circuit?

I created a product demo box that completes a circuit once the "push to start" button is pressed. Closing the circuit allows the customer to see my product in action while holding down a ...
• 51