Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [low-voltage]

Low voltage refers to voltages in a range from 1) 50–1000 Volts AC [Vᵣₘₛ, rms…root mean square] and 2) 120–1500 Volts DC according to standard IEC 60038 of the International Electrotechnical Commission.

Low voltage refers to voltages in a range from:

according to standard IEC 60038 of the International Electrotechnical Commission.

219 questions
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How safe is 48V DC?

In many Power over Ethernet (POE) setups the transmission voltage is 48V or slightly more. While higher voltage has obvious efficiency advantages, how safe it is? Is there any risk of electrocution when accidentally exposed, in particular to…
Petr
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Why do many electronics operate on 5 and 3.3 volts?

Many modern appliances use a 5V power connection, but internally they work with 3.3V. Wouldn't it be easier to have 5V everywhere? Examples are many USB devices or routers (they use 5V for power but 3.3V for serial communication.)
Moe
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How can low voltage, high current (kA) power be dangerous?

Aluminum refineries use electricity to separate aluminum from minerals it naturally occurs in. This electricity typically takes the form of low voltage DC ("low" meaning 4 to 6 volts), at very high current (on the order of tens of kiloamps). This…
ItsAmy
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Lighting up an old vacuum tube

Does anybody know how to light up a vacuum tube? I have about 9 of them and only 1 I can see the name. It is a 12DT8. Is it possible to find the heater without the datasheet by using a multimeter etc... And if so, is it possible to power it with a…
skyler
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Mains to low voltage seperation between FR4 PCB layers

I cannot find clear information on running mains and low voltage on adjacent layers on FR4 PCBs. I understand how much creepage distance to allow, but for example, can I run - 50Vdc, 240Vac, 0Vac, ground, on a 4 layer 1.6mm FR4 PCB. Would it be more…
Garth Oates
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Powering and dimming a few hundred light bulbs

I want to power a very large light fixture: it has 273 G4 socket light bulbs. The bulbs I found for the thing are 12 V 5 W ones, incandescent. So the question is how to power the beast (as it is 1365 W of power), and how can I dim the whole…
A. Daty
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Anything special to consider when running a 12v "Bus" throughout my house?

I've recently begun playing a lot with tiny programmable computers/controllers (like the Raspberry Pi and the Arduino), and I'm planning to distribute several throughout my house as various sensors. So far as I have been tinkering with them I've…
loneboat
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Is it okay to charge a deeply discharged Li ion cell below 1V?

I accidentally discharge my lithium cell to 0.45V. Is is okay if I try to revive it by charging with 10mA of current till it reaches 2.5V? cell capacity is 4000mAh.
Sudip Kongbrailatpam
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Can a novice safely splice in wire to lengthen 5V charging cable?

I have a 5V 1500 mA charging/power cord for a camera that was too short to reach the mounting position I need, so at the suggestion of my electrical engineer father, I decided to try to lengthen it. He said to just twist and tape the wires together…
xr280xr
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How to interface with ultra-low voltage microcontrollers?

Cypress has PSoCs which can operate at 0.5V power supply. I was wondering how you interface these. 0.5V is too low for FETs and bipolar transistors, LEDs and even common diodes. So what ways are here to connect the PSoC to its peripherals? Low-power…
Federico Russo
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How fast can a transistor switch?

An NPN transistor can be made a switch by applying some power to the base. Is there a limit to how fast I can switch the transistor on and off, or I can switch it on and off as fast as I can turn the signal to the base on and off? As switching, I…
Bryan
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Standards for vehicular lighting connections

I am a cyclist and electronics hobbyist, so I am designing an electrical system for my bicycles. THE QUESTION "What do I need to know (standards, available components, good practices) so that I can design the proper CONNECTIONS in the system, either…
heltonbiker
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270a DC inrush, 130a DC nominal load. 14 vdc supply. Ways to limit circuit to no more than 11.5 vdc?

What device can be installed between the glow plug relay and the power leads to the glow plugs, to allow ANY voltage under 11.5 vdc, but allow no more than 11.5 vdc, regardless of how much higher the supply voltage exceeds 11.5 vdc? Background The…
Herbert
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How to determine which harmonized standards are relevant to achieve CE conformity declaration

We are aiming to develop our first product to achieve a CE marking. So far i understand that there are a few directives like Low Voltage Directive (LVD), ROHS, EMC, etc, which can be implemented by sticking to harmonized standards (e.g.:EN55022 for…
Jogitech
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Do low voltage "Nixie tubes" exist?

I want to make a small clock using Nixie tubes (for the cool/retro/steampunk look of them), I have some basic knowledge of electronics, but I have never done anything with more than 12V DC and ~10A. I saw that Nixie tubes are usually using 3mA at…
EngelOfChipolata
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