Questions tagged [standard]
For questions about technical standards such as IEEE standards. Examples of such questions include: what a standard requires, how to meet the requirements of a standard in a circuit design, what capabilities and limitations a circuit designer can assume when incorporating a standards-compliant component in a design, etc.
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IEC 61000-3-3 flicker for switches and relays
IEC 61000-3-3 shall be used for testing all 230V 50Hz AC devices with up to 16A current rating.
What about switches, relays, power plugs-basically devices that act as gateways between mains and actual ...
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Is there a specific definition for the tolerance value of a resistor?
Is there any authoritative definition for what the tolerance value of a resistor actually specifies, or is it just a de-facto common understanding, or are the details left up to individual ...
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CT Standards for HV Breakers (145 kV) - Siemens
I (young, new engineer) am researching the standard CT ratio for a Siemens HV circuit breaker for my senior engineer. He tells me they don't post their standards like other companies do and I am ...
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Is it legally allowed to install lightning rods in rainy or cloudy weather?
I had a look at some standards (such as IEC 62305 & IEC 62561 Standards for Lightning Protection) on how lightning rods should be constructed, and also searched the internet. I found no real ...
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Does a non-isolated PoE Splitter comply with IEEE 802.3 clause 33.4?
PoE Splitters that are freely available on the market for purchase by end users frequently are non-isolating, i.e. their power output is galvanically connected to the twisted pairs of the Ethernet ...
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Power Quality Measurement & Reporting Standards
I'm analyzing power quality in low and medium voltage facilities (50/60Hz; 0.48 - 69 kV; factories, campuses, etc.) while trying to apply existing standards wherever possible. In addition to demand ...
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Is it possible to transmit/receive 16 bits in single symbol with the UART?
In the "Universal Serial Bus Class Definitions for Communications Devices" document there is the "Class-Specific Request Codes" table. In this table there is the GET_LINE_CODING ...
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Trying to identify DC connector (5.5 mm OD, 3.0 mm ID, no pin)
I need to replace a DC adapter for an old NAS that was lost to a power spike but I'm having a hard time identifying exactly the kind of connector.
This is the connector on the back of the NAS:
I have ...
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Are USB 2.0, Type-A, Male-Male cables compliant with USB specification?
This was asked 3 years ago in a similar question but it left out some information to be desired. Are male-male, type-A-typeA usb 2.0 connectors safe, and/or compliant with current standards? Are they ...
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What is this standard for phone wire colors, found in Lithuania?
I have found disused phone wiring in the walls of a house in Lithuania. The cable was probably installed around 2014 and has the following wire colors:
white
yellow
orange
green
gray
red
White/...
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Are there any useful points of such a large functionality of USB HID class?
In the list of USB classes, in addition to the obvious things (like "Printer", "Hub" and "Storage"), there are also such things like "Audio", "Video", ...
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Help with component choice for weather proof sensor node
I'm planning on making a wireless weather station with a sensor node and a master to display the sensor data. The sensor node would be placed outside and measure temperature, humidity, and air ...
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Where can I find information about "Enhanced Policies and Procedures Exam" for IPC?
I'm taking the CSE test for IPC-J-STD-001 and at chapter 7.Certification Exam Overview, I can see that there are 3 types of tests.
Policy and procedure test (10 questions)
Closed book test (25 ...
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Where did the 156 mil / 3.96 mm pin spacing standard come from?
Along with countless sensible pin pitches like 100 mil or 2 mm or 200 mil, on certain things like card edge connectors and terminal blocks, a pitch of 156 mil is common. But where did the number 156 ...
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What standard defines the number of stop bits in RS-232?
There is an option in many terminal programs or ICs to set 1 stop-bit, 2 stop-bits or 1.5 stop-bits. Is there any standard that says the RS-232 can have only 1/1.5/2 stop-bits but can't have 0.5 or 3 ...
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A question regarding technical standards
I'm not sure whether I can ask this question here, but since I feel that it is somewhat related to electrical, I am asking here.
I read that the CAN bus was originally developed by Bosch, but they ...
user220456
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Creepage between layers on a PCB
I'm currently designing a power supply with high isolation between primary and secondary sides and have to comply to standard distances on clearance and creepage.
My question is regarding creepage, I ...
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How do I determine the acceptable delay spread in an analog FM simulcast LMR system?
I'm using a commercial propagation analysis software to analyze a legacy VHF simulcast Land Mobile Radio (LMR) system. I'm trying to analyze the parameter "Delay Spread". The software ...
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AWG and metric markings on wire differ notably
I have been looking at "Tri-rated wire". This is wire that ostensibly meets the British BS6231 Type CK, US UL 758 Style 1015, and Canadian CSA 22.2.
I have noticed that the metric wire size (...
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LTE PC5 Subframe Structure
LTE provides sidelink communication via the PC5 interface.
According to the "secondary literature" [1],[2],[3], the PC5 subframe is structured as follows:
Symbol 0,1,3,4,6,7,9,10,12: PSCCH, ...
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ISO/IEC Power/Ground Symbol in schematics?
Yet again, we are debating with colleagues to choose the correct power symbols in our schematics.
Some argue that using the horizontal 4-lines symbol for GND is a misunderstanding because this is not ...
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How unsafe is 220V over NEMA 5-15 really?
I'm from the Philippines but the U.S. had a very large influence on our electrical standards. It is especially evident on our electrical sockets.
While all of the sockets in a typical Filipino home ...
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12V-only (and no 110V/220V) household electrical installation [closed]
Power outlets are in 220V/110V in houses for historical reasons (light bulbs and other appliances probably required >100V voltage) but nowadays as:
we use a USB charger 220V->5V for phones, ...
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Interface a CML device with FPGA
I want to interface an IC with an FPGA however I noticed that the datasheet says the digital control inputs are differential and CML standard based. Can someone please guide how to interface this if I ...
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Are There Any Standards for RTCs, Similar to JC42 Temp Sensors?
When I place a temperature sensor on a board, I like to use a JC42-compliant temperature sensor. I know of at least half a dozen manufacturers that build these temperature sensors in exactly the same ...
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Standard for batteries in emergency lights
I am not sure if this question fits this community.
I would like to know if there is any norm or standard for batteries in emergency lights for rail purposes in European countries, for example, some ...
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Is there a standard PoE+ input symbol for a product label?
I was expecting to easily find this. However, unlike other safety symbols (such as double insulation / Class 2) I cannot seem to find a lead.
Was convinced this would fall under some sort of safety as ...
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If a device's electrical requirements give a voltage range and fixed current, does the current limit assume the lowest input voltage? [duplicate]
I am working with some small devices and checking input power requirements. Many of the standard labels look like this:
Input Power: 100 - 240 VAC, 50-60Hz, 2.5A
I am trying to determine how much ...
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Does the standard for M12 A-Coded 4-pin plugs (female) have a dummy center hole to accommodate 5-pin socket (male) connectors?
I have a project that will tap into an existing sensor that uses a 4-pin M12 A-Coded connector. My plan is to use a Y Splitter to allow me to tap a parallel connection to the sensor.
The splitter I ...
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Can I use this US extension cord in Europe? [closed]
Long story short: I need an extension cord to charge my EV when the standard charger does not reach the socket. I spent hours researching what options I have and most review websites I found were US-...
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How is TCF calculated for a Current Transformer?
I'm trying to understand the IEEE C57.13 standards for current transformer metering accuracy, and I don't understand how the Transformer Correction Factor (TCF) is defined for current transformers. ...
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How to choose the right flexible cable for moving parts?
Is there a generally accepted guide to select a cable, which has to withstand certain bending stress?
I am looking for something like this:
...
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Rs485 A & B Labels being used inconsistently
I would like to know if there is an official standard with regards to rs-485 terminals being labelled A & B.
I have always believed:
A=> + (positive)
and
B=> - (negative)
however, I have ...
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Electromagnetic compatibility (EMC) standard
I have been working on a battery fast charger of around 500W. I have been wondering if active power factor correction (PFC) is necessary and have seen people mention a European standard EN 61000-3-2. ...
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Transformer secondary conductor protection: how do NEC 240.21(C) and NEC 240.4(B) make sense together?
NEC 240.21 says all ungrounded circuit conductors require overcurrent protection, with a list of exceptions:
One of those exceptions is 240.21(C):
240.4(B) says that if you're under 800 amps, you ...
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Must the device I am developing conform with IEC 61010-1:2010 standard?
I am developing a device that contains 5 inputs (piezo buttons) and 5 outputs (2x pump - induction motor, fan - induction motor with basic speed control using dimmer circuit, 2x source for LED ...
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What are the standards for hand placing components?
Is there any written specification for the orientation of components on a manually assembled PCB, including both THT and SMT passive components?
'Manually' because machines can be easily setup to ...
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What is the proper reference designator for a ring terminal in a cable drawing?
I am working on some cable drawings that utilizes ring terminals that connect on a relay terminal. Initially, I was using T as the reference designator for them, but I realized that is incorrect since ...
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What happened to the M2.com standard?
I just discovered some news articles from 2016 announcing an IoT standard called "M2.com", with quite a few big names supporting it. It was basically meant to be a standard pinout for the M2 ...
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Is there a "standard connector" for SPI, in a similar way to the "standard Qwiic connector" for I2C?
I really love the "standard Qwiic connector" initially intoduced by Sparkfun for connecting / "chaining" I2C components. Really amazing and super convenient in day to day life when ...
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Is there a published standard for 'euro modules'?
Variously called 'Euro modules', 'Euromods', 'Euro modular', these are 'standard' sized units (1U, 2U, ..) that slot into face plates - e.g. a 1-gang face plate can take 2U; 2-gang fits 4U - that can ...
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Is there a resource to look up widely in-use/standard connector styles?
I'm working on rebuilding a design that currently uses obsolete parts. I'm taking the opportunity to increase reading accuracy. In doing so, I will have to replace our current connector to go from a 2 ...
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Which UL standard(s) holds the specifications of all UL AWM styles of cabling?
Which UL standard documents the specifications of all UL AWM styles of cabling, detailing their construction, conductor sizes, insulation, etc. ?
In my research, I was directed to UL Standard 758 ...
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Wire color standards for a reversible DC motor [closed]
I'm working on a project with a DC motor that runs in both directions. If the motor ran only in one direction, I'd use red/black for positive and ground, but as they reverse, there isn't a consistent ...
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Square wave, triangle wave etc. not defined in International Electrotechnical Vocabulary (IEV.) Are they not standard terminology?
Why are there no definitions for typical terms like square wave, triangle wave etc. in the International Electrotechnical Vocabulary (IEV)?
Are these widely used descriptions not defined by ...
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Is a VL3030 coin cell battery a suitable replacement for a ML2430?
I am attempting to replace a battery in my electronic compass and im supposed to use an ML2430, however this is proving to be hard to get hold of and expensive.
I'm concidering using a VL 3032/HF5N ...
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Is there a standard equivalent to automotive standard AEC-Q200 for the medical sector?
I want to ensure components of high integrity characteristics are utilised in a design by a third party.
In the automotive sector AEC-Q200 can be stipulated, e.g. (https://www.digikey.com/en/product-...
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Is there an international standard on the frequencies used by car toll tags?
We're finding that when we drive through a car-toll collection point, our Car-Pay Wifi connection cuts out. (Music and maps cut out).
I'm guessing that the Car-toll tag system uses the same ...
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What standard must a component/ device comply with to be industrial grade?
I am looking at an iot device that claims to be industrial grade.
It meets standards such as UL60950-1 and has an operating temperature -40 --> 85C so looks good but is that enough?
Exactly what ...
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