Questions tagged [detection]
The detection tag has no usage guidance.
214
questions
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0answers
37 views
Converting a PWM signal to reduced constant voltage or constant current output
I'm dealing with an existing circuit that was originally designed to dim incandescent and halogen bulbs from 12V using low frequency PWM. This PWM is visible to the naked eye when substituting a 12V ...
1
vote
1answer
108 views
How is this circuit detecting the LED?
so I've just built a circuit and some Arduino code (not shown here) which interfaces between a car steering wheel and its buttons to an aftermarket cruise control system (Command AP500). The stock ...
0
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1answer
114 views
48V Lithium Battery Cutoff Detection Circuit
I'm building a power system using four x 48 V 100 Ah lithium batteries in parallel (48 V 400 Ah nominal). The batteries are already purchased, there is no going back. The cells cannot be accessed, ...
3
votes
1answer
55 views
How does a grid-tie solar power inverter know when the mains power has failed?
Solar power inverters that send excess solar power back to the grid are (usually) required to shut down if the grid power fails. (This is to protect people working on the power lines.)
The inverter ...
0
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1answer
83 views
Friendly target identification in radar
Crossposted from Signal Processing stack exchange,
How do radar systems identify friendly targets to avoid AA locks during combat scenarios?
Do friendly planes broadcast a known signal or is something ...
0
votes
1answer
46 views
Circuit to detect in which port sensor inserted
I want to build a Counter using a Proximity Sensor. I want to give choice for user to use either PNP or NPN. I will give two ports for the same. I am using PIC16f887 microcontroller.
How to detect ...
0
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0answers
127 views
Open circuit fault detection using an Arduino
I was able to implement short circuit fault detection of under ground cables and I was also able to add a GSM module(SIM900D) with it.
I'm trying to further enhance my project by detecting open ...
0
votes
3answers
83 views
Can LED strips be used as photodetectors?
As I did not find any photodiode/PD strips available, I am wondering if it would be possible to use LED strips as photodetectors. And if yes, which type of LED strip could be used for that purpose?
My ...
7
votes
3answers
855 views
Amplifying 40ns pulses that come at unknown times (for single photon detector)
I have a single photon detector produces a 40ns signal when a photon enters the detector, like the image below:
I would like to take this electrical signal and hook it up to this device which simply ...
0
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1answer
103 views
Reliable 110 & 230V AC line detection on 3.3V GPIO
A manufacturer provided the following circuit, to detect AC line voltage in a small IoT module (non-isolated power supply).
SW1 is pulled up with an external 10 kOhm resistor and connected to the ...
0
votes
1answer
44 views
How to detect AC or DC voltage from 9V DC to 250V AC?
I have a device that needs to detect the presence of voltages from 12V DC up to 240V AC RMS (Absolute maximum of 9V DC to 250V AC RMS) This device is going to have up to 8 channels that should be able ...
0
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2answers
59 views
How to detect a capacitor installation
The circuit I'm designing uses external capacitor to measure its ESR. I use MSP430 as a controller, capacitance of the external capacitor can vary between 100n and 10uF. The problem is I should ...
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0answers
26 views
General approach of signal detection after demodulation of BPSK
I'm very new to electrical engineering. I'm trying to understand the basic approaches/options to detect symbols after demodulation of BPSK. I found some articles mentioning Maximum Likelihood ...
2
votes
2answers
69 views
Does the bandwidth at the receiver really affects the noise in digital modulations?
I know that, in a telecommunicacion system, the AWGN power after going through the receiver filter is
$$
P_z = KTB
$$
where B is the bandwidth of the filter, T is the operating temperature of the ...
0
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0answers
62 views
How to detect the presence/ absence of a PWM signal on a GPIO pin?
I just want to set or clear a flag by detecting the presence or absence of a PWM signal with approximately >100 kHz frequency on a GPIO pin. I studied that a simple RC low pass filter can be used ...
0
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0answers
53 views
How to detect an I2C slave presence/ absence as an interrupt?
Involved in a task to build a test equipment with a ARM M4F microcontroller for the purpose of testing various PCBs. One of the PCBs has I2C compatible current/voltage monitoring chip on it. Is there ...
1
vote
1answer
58 views
Which sensor should I use to recognize just humans? (not all of the obstacles)
I would like to make a social distance meter and the device should only avoid from humans, not the obstacles. I'll use an ultrasonic sensor and a PIR sensor but I'm not sure it will be enough. Do I ...
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2answers
87 views
Why can FM be demodulated non-coherently while PM cannot be demodulated non-coherently?
I have read that frequency modulation has the advantage that it can be demodulated non-coherently while phase modulation can only be demodulated coherently.
I don't find any reason to support this ...
2
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1answer
62 views
Why is transformer coupling used in a simple slope detector? Can't the FM signal be applied directly in parallel to a tuned circuit?
This is what I mean by simple slope detector:
Why can't it be like:
0
votes
1answer
198 views
Is it possible to use a Multimeter for detecting electric leads?
Is it possible to DIY my multimeter into a detector for active wires (charge flowing at that very moment) inside a wall?
I don't know, maybe something with a coil or metal plates?
The application ...
1
vote
1answer
62 views
Help recognizing components and parts of this radio telescope [closed]
I stumbled upon this video, where someone is showcasing a radio telescope that detects wifi frequencies and renders them as picture.
There are three parts, and the one above is just the 3rd part (last ...
0
votes
1answer
98 views
Can a voltage divider be used for (input) jack detection?
I would like to detect when a jack is plugged into my connector. The circuit looks like this:
One end of the jack is connected to a speaker, and the other to an audio source, such as a phone or mp3 ...
1
vote
3answers
101 views
Why the same sound source (low frequency, possibly infrasound) has different frequencies in different rooms of the house?
Can someone explain me why the same sound source has different frequencies in different rooms and if there is some type of correlation between the vibrating frequency and the distance between the ...
0
votes
1answer
70 views
Composite video from rear car camera - bad signal (wrong levels?)
I have bought a car radio (AMPrime 4022D) that has ability to connect rear camera to it, so you can see the image on its screen. The problem is that radio doesn't detect the signal (blue screen).
But ...
0
votes
1answer
54 views
Detecting when the thermostat turns on the refrigerator
I'm wanting to monitor the power consumption of my Fridge (and Freezer) on a boat where the voltage runs from 12-15.6vDC
The Thermostat is an Inkbird(from Amazon) that closes a relay when the ...
1
vote
1answer
121 views
How to avoid false detection when using IR object detection circuit?
I have a circuit to demodulate 2KHz Infrared pulsed light which is generated by 555 timer IC and its output drives an IR transmitter circuit, which is received by IR receiver located 10 cm apart which ...
3
votes
3answers
136 views
How does this surge protection work?
This circuit signals an MCU via OU lead. I am not interested in the MCU side. I just show the concept.
My question is very simple: How does the surge protection(actually ı meant detection) part work?
...
0
votes
1answer
82 views
How to find which landline wires are mine using sensors on my cell phone?
How do I figure out which one is my line? I know there's a special tool for it, some sort of beeping proximity sensor. I don't want to buy any tools.
My cell phone, like many, has a Magnetometer. ...
0
votes
0answers
157 views
How to design a no-load detection circuit and auto cutoff if load is not presented?
How to design a no-load detection circuit, I couldn’t find a reference design,
Is this possible task to perform?
Load is an LED setup, 150V DC, 30mA
If load is not connected to the circuit, power path ...
0
votes
1answer
102 views
open wire detection of open drain output
I am working with a commercial dc motor speed controller it has a open drain output which can be used for generating fault signals , i am taking that output to a pcb through wire , i am giving it a ...
0
votes
1answer
57 views
Hidden wire detector, using resistor
We have on the collector of the first transistor is a resistor at 1000 ohms , could you tell us what function this resistor performs in this place and how to argue that it is at 1000 ohms
0
votes
1answer
139 views
How to detect when an LED has burned out?
I'd like to have a way to detect when a low power LED burns out (2-3.5v, 200-400mA) that is being driven using PWM from a Raspberry Pi with a MOSFET.
My understanding is that I would be able to ...
0
votes
2answers
107 views
Hidden wire detector using BJT transistors
I made a hidden wire detector from this tutorial. It works, but I'm not quite understand why. Here is the circuit:
I used 2SC1815 transistors and the value of R ...
0
votes
1answer
80 views
How to detect in the code (Not have to design any extra hardware) if a (peripheral) PCB has been inserted/ plugged/ interfaced to the main PCB?
I have a main PCB with a microcontroller on it with lots of connectors on it to connect to many other (peripheral) PCBs which have sensors and report data to the MCU on the main PCB.
I wanted to ...
0
votes
1answer
80 views
How to detect a magnetic field from a distance?
I want to detect a magnetic field, like those of small neodymium magnets, from at least 6 inches away (the further the better, I'd like at least a foot but I won't ask for too much). I'd like to do ...
0
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0answers
79 views
Wireless torpedo charger: Coil design and torpedo detection
I'm building an RC submarine with torpedoes and I thought a good way to power them would be with a capacitor. To keep everything water tight, I am hoping to use wireless charging. Here's a rough ...
1
vote
1answer
87 views
UART broken wire detection
I am planning to create a broken wire detection between a UART communication. The main idea was to check the Tx and Rx lines with a retriggerable astable Multivibrator which creates a HIGH Level on ...
0
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1answer
230 views
Defect LED detection for car lights
The schematic beneath is a new project of me.
The theory behind this is: My car has a very fool proof bulb failure detection and warning system. CANbus proof LED bulbs can't fool the car and just a ...
0
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0answers
43 views
What options for detecting presence?
I'm not looking for product recommendations - I'm looking for advice on what different kinds of devices exist that would be capable of detecting the passing of an item of clothing on a rubber conveyor ...
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1answer
69 views
Designing a frequency detection circuit [closed]
Hi i was wondering if its possible to make a digital frequency detection signal which detects which generation is being used by nearby mobile phone ie:gsm 3g 4g the frequency band varies according ...
3
votes
2answers
1k views
Isolated mains (AC) presence detector
I need to detect a AC mains outage, isolated way. Output marked as [?] goes to AVR MCU. I don't need to detect undervoltage or zero-crossings. I actually need a simple feedback to MCU interrupt which ...
-1
votes
1answer
93 views
circuit to detect chess clock toggle change to fire BT button
I was looking for simple circuit: (SamGibson's idea to add a 2nd reed switch proved possible, see update below.)
to detect transition to flat 0 V when player B's clock is running.
to detect ...
1
vote
0answers
143 views
How can I increase the distance of a photodiode
simulate this circuit – Schematic created using CircuitLab
I wanted to make a fire detection system using a photodiode, comparator with potentiometer to adjust sensitivity, and an alarm circuit ...
0
votes
1answer
55 views
Fast mains outage detector
What is the fastest mains outage detector at <1ms?
Anything that uses a 12V DC adapter or a mechanical relay is not an option for me because it has a long delay.
Is there an AC driven static/solid ...
1
vote
0answers
84 views
Composite video signal detection problem?
I have an android headunit and I installed a reversing camera to it.
The problem is that the headunit does not seem to detect the camera signal if the environment is too bright. It just shows black ...
1
vote
2answers
457 views
touch sensor for metal door handle
I was thinking if a current is applied to a metal door handled and somebody touched it that should complete the circuit to ground and be detectable but I'm not sure if this would work as the 'somebody'...
0
votes
1answer
140 views
How to get a 1 clock period pulse from a constant input? [duplicate]
I want to make a digital circuit that produces a pulse 1 clock period in duration whenever I see the input to the circuit go HIGH. I only have a flip-flop, an AND-gate, and an inverter. How do I ...
0
votes
1answer
86 views
door bell detector using NodeMCU
i modified my door bell with a NodeMCU which is now capable of triggering the door opener using a relay. Now I want to add a door bell detection to this system. I figured out two contacts which supply ...
0
votes
1answer
182 views
What type of sensor to detect if an object passes through?
(Sorry for my bad English)
Hello guys, I need your help since I have no idea about electronic stuff.
I have a table soccer and want to install motion sensors in the goals, so whenever the ball ...
-1
votes
1answer
90 views
USB type c receptacle plug in detection
How does usb device with type-c receptacle detects, that plug (just bare usb type-c plug, without cable, and resistors) is attached?
Does USB specification describe this possibility?
I know, that my ...
