Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [current-rating]

30 questions
13
votes
4 answers

According to my understanding, this induction heater should be melted, but it's not. Why not?

I opened up this induction heater to find that it only has maybe 12 AWG wire in its work coil, rated for 30 A RMS. I've been doing induction heater simulations for a project, and the two topologies I've looked at (series and parallel half-bridge…
Popeye
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6
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1 answer

Why do the normally closed and normally open relay contacts have different current ratings?

Please refer to the image below: Taken from the datasheet: http://www.songchuan.com/db/pictures/AdminModules/PDT/PDT090410001/201191913495127935.pdf
lukecam95
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6
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4 answers

How to determine the nominal current of an LED?

I salvaged the LED disk from a defunct LED light bulb. (The problem was an arced transformer, the LEDs are intact.) It has several unmarked white SMD LEDs soldered on it: 5 lines parallel, with 3 LEDs in series on each line. I want to use this disk…
Neinstein
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4
votes
1 answer

Molex PicoBlade current rating confusing

It seems there are confliction in specifications of PicoBlade for current rating. From the MolexPicoBlade Connector System datasheet, I assume that the current values in table is per circuit value. So, with 26AWG 2-circuit, I can transfer 2.5A for…
slyx
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3
votes
3 answers

Why are switchgears rated in specific capacities such as 63A, 100A, 125A and so on?

I am working in a consultant industry, wherein we get the switchgears from different OEMs. I wonder why the switchgears (including fuses and fuse-gears) and control gear assemblies are rated in the specific values for all the manufacturers. And…
DaSnipeKid
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3
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2 answers

Create Transformer Center-tap From 2nd Secondary

After ordering this 200VA, 32V transformer, I realized that it doesn't have a center tap on each secondary, which I need to have. (duh on my part) So I want to use 110V across the 220V primary leads to give me half the voltage at each secondary,…
Kent Weigel
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3
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2 answers

Potentiometer overheating - is it due to current rating?

I need to get a pump running at different speeds so I ordered an electric motor, a potentiometer and a power supply adapter. I put them all together and they worked, however the potentiometer got burnt out. These are the items: Electric motor: RS…
Roxana Radu
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3
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6 answers

Why do some wire gauge ampacity charts state vastly different current ratings?

This is a question that I've had for a while but have somehow managed to go without asking. Looking at all the wire gauge ampacity charts online, some of them appear to provide vastly different ratings for the same wire gauge. I understand this may…
Izzo
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Where do AC/DC power adapter manufacturers get their high amperage (>12.3A) barrel plugs?

I was looking to swap out a barrel plug on a spare Dell 240 watt AC/DC power adapter to avoid having to purchase a ~$80 replacement with the correct plug. I went off to Digikey and Mouser in search of a suitable plug (5.5mm OD x 2.5mm ID) and found…
HanniballRun
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1 answer

If a device is rated at 12 V/80 mA what does that mean as far as the length of time that it will draw 80 mA?

I have an electromagnetic device designed to hold a fire door open until either the circuit is cut or the building's electrical supply goes out. At which point the door is released and will close. It is rated as 12 V/80 mA. What does that mean in…
BobNll
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2
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1 answer

How to calculate the maximum current rating of an ammeter manganin shunt?

I want to make a shunt for an ammeter using a manganin wire. I don't know how to chose the wire diameter for the desired current. For example, my shunt will have 0.05 ohms and it must withstand 5A for a continuous usage and 10A for short periods of…
Marus Gradinaru
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2 answers

Voltage/current rating for center-tapped rectifier vs. full-bridge rectifier

I am currently working on an LLC resonant converter. While reading an application note from ST microelectronics, I found something about using different rectifiers for different purposes. I understand that we would have half the voltage in a…
ishankhowal
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2 answers

Current Rating of a device (how does this change when changing the voltage)

Let's say you have a device that is rated at the following: 550 amps @ 12Vdc (heat) Max Voltage = 48Vdc (insulation material max voltage rating) I am mainly concerned with the heat, we could say the device is able to handle: 550A x 12V =…
Busta
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How to guess voltage ratings and current ratings in capacitor and inductor?

I have a list of values of capacitors and i also know their material types! But i don't know how to figure out their voltage rating? "Ratings have been removed in the capacitors for this purpose" Also for my inductors, i have their value.But i have…
Hilton Khadka
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Electrical Project containing parts with different volts/amps rating

So I have a small project just for fun. Includes a Peltier module , and a small cooling fan like the ones used in a pc for airflow. So my question is since the peltier module have a different rating than the fan. Is there any way to use just one…
AnnoyingGarlic
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