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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What rule or standard is used to assign a SOT number to a chip housing?
I studied the datasheets of some Philips chips and found that they housing have several designations. In particular, many packages are signed like DBS9P (as I ...
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3
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How is the AWG rating of a ribbon cable interpreted?
Suppose a ribbon cable rated 24 AWG. Does the implied current limit apply to each conductor separately or to the overall ribbon if all conductors are used in parallel? Or in other words, how much ...
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Why are there no 12V/5A USB PD chargers/batteries?
Any 100W USB PD 3.0 system must support 20V/5A charging. Naively I assumed that therefore they should support 5A at any of the lower voltage rails! But for some unclear reason, I cannot find any PD ...
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What are the hole dimensions for 0.1" pitch headers?
What are the hole dimensions for 0.1" pitch headers?
As discussed in How to breadboard with large lead components (such as TO-220)?, holes on standard 0.1" pitch headers are:
Rectangular (...
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USB A mechanical orientation?
This concerns a USB A socket on a PCB.
Is there a standard or preferred orientation of the polarization tab, either up or down?
The picture shows one with tab towards the top
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Standards/Insight into Transient Protection of Industrial/Construction Equipment
I am designing a device that will be connected to the 12 or 24V battery of certain construction and industrial equipment. I'm aware that because these are industrial vehicles/equipment we will need ...
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Is EMT plenum rated? If I install EMT in a plenum and run general purpose wiring through it, does this violate NFPA 75?
I have a raised floor area with a few server racks on top, the under floor area is used to distribute HVAC to the racks. I have already run all the cables before learning of NFPA75's plenum rating ...
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Is there a standard which requires a high voltage warning label on a PCB?
If part of your PCB carries high voltages at certain nodes, is there a standard that requires some sort of silkscreen label or sticker to warn technicians when installing/uninstalling boards into ...
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Symbol of short circuit (or termination) with an Earth
Can someone explain to me why the symbol of the valve arrester has a short circuit, if it is already earth? I don't understand why it is depicted like this.
Why does the valve arrester have the symbol ...
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C7 plugs with 3A fuses
IEC 60320 C7 type plugs seem to be rated at 2.5A, yet they are commonly supplied and used in the UK on cables where the source side plug is fused at 3A. Does this meet standards, and is it legal and ...
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Industrial product IEC 61000-3-2 compliance
I have a question related to IEC 61000-3-2 standard for current harmonics limits.
I am working on an industrial product rated for 500W that connects to the grid (220VAC).
The standard states that ...
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Standard defining whether to strip multi-core cables inside the cable duct or close to IO Card
During the factory acceptance test (FAT) of a remote IO panel (24V, atex zone 1,) the client did not accept that the multi-core cables were stripped inside the panel wire duct. He said that they ...
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Power limitations for Ethernet cabling
I have a 60 watt constant current Meanwell driver that has the following output options:
.9 amps @ 67 volts or 57 volts @ 1.05 amps. I want to know what specific ethernet cable is required. Can I ...
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Is IC power pin position (V+ / V-) for a package mostly standardized for opamps, comparators, INAs etc.?
Is the power pin position for certain types of ICs standardized or practically, mostly standard? I assume there are rare exceptions and manufacturers could do what they want, but the general answer to ...
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Electrical Standards for Exposed DC Connections
We are trying to make a slide lock connection between two parts and thus need to have some sort of connector between them.
I am wondering if anyone is aware of a IEC standard relevant for connecting a ...
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How to plot standard deviation in Advance Design System (ADS) software?
I have measured several sets of data using a Vector Network Analyzer, and my data is in S-parameters format. How can I draw a standard deviation plot in ADS software based on my data?
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Which faults of dual transistors on isolated dice must be considered according to IEC 60335-1?
I got the task to upgrade one of our products to comply with the requirements of IEC 60335-1, which means, that no safety function must be lost in case of a single component fault. To save space and ...
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EMC and Control Area Networks [closed]
With radiated EMI tests, do we need to take into account the communication cabling and its influence on EMI?
I can't seem to find one standard that describes how CAN busses should be configured in EMI ...
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How were standard serial port baud rates chosen?
How were standard serial port baud rates chosen? 1200, 9600, 115200, aren't the numbers we'd expect (powers of 2 or 10), but don't seem random either.
Wikipedia states
Many of these standard modem ...
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What's the *actual* meaning behind the I²C reserved addresses?
I'm building a i2c-tiny-usb compatible adapter, and am trying to implement a "transparent side channel" for advanced configuration/features of the adapter....
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How should I select appropriate capacitors to ensure compliance with IEC/EN 61000-4-2:2009 and IEC/EN 61000-4-5:2014 standards for my device?
When applying the IEC/EN 61000-4-2:2009 and IEC/EN 61000-4-5:2014 standards for our device, our consulting firm recommended bypassing the input power jack to the chassis ground using two 33nF ...
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Will someone judge my circuit schematic?
I've got an interview for my first job out of university coming up, and I'm preparing a presentation on a project I did a while ago. I'm currently translating my hand-drawn schematic to a computer-...
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Television repair - connectors and standards for display panel and controller boards
All my experience comes from 2 flat TVs, so my knowledge is quite reduced and questions have to be quite broad.
Questions:
Are there standards or common practices from manufactures about connections ...
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CAN protocol for communication between EV and Charging equipment
I am trying to understand (and hopefully build) DC fast chargers (GB/T) for electric vehicles, specifically the communication between the Electric Vehicle Supply Equipment (EVSE) and the electric ...
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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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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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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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1
answer
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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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Has the user's guide for the UVM-IEEE-2020 framework been published yet? [closed]
I was able to find the User's guide for the UVM-1.1 and UVM-1.2 frameworks, but I haven't been able to find the same document for UVM-IEEE-2020.
There are of course resources posted at the Accellera's ...
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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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2
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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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0
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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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