Questions tagged [transformer]
A transformer couples two or more AC signals through a magnetic field. Often used as galvanic isolation and to transform one AC voltage to another.
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accurate method of determining turns ratio of single phase transfomer
In determining the turns ratio of a single phase transfomer ,we are asked to use voltage ratio (Vp,Vs) side by side current ratio(Ip,Is). we open circuited the secondary transformer and put test ...
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How Should I Model Eddy Currents in a Magnetic Core?
simulate this circuit – Schematic created using CircuitLab
simulate this circuit
I'm primarily a VHDL and DSP guy, so I apologize in advance if this question is dumb.
I have wire wrapped around ...
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Reducing Isolation Transformer Leakage
I watched this video and wonder if its complete separation of primary and secondary coils is the normal way to wind a low-power isolation transformer (e.g., 60Hz 120V 120VA).
I particularly want low ...
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Does all the current lag the voltage in an inductor or is it only a small component?
the way I understood a basic inductive circuit (voltage source + inductor) is that all the circuit current (Io) lags the voltage by 90 degrees. However, I am following this blog tutorial to refresh ...
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Designing a power supply circuit for a DC motor speed control circuit
I am designing a a power supply circuit for a DC motor speed control circuit.
I am using Proteus to simulate it but it is not working.
I am using a step down transformer to take 230V to 16V then ...
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How do steel laminations reduce eddy current losses in a transformer?
All online materials I have read so far state that laminations reduce eddy currents but how is this so? I mean why would currents be smaller this way than having a big block of unlaminated iron core ...
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Common mode EFT protection with a transformer [closed]
I am using a transformer (VN38.13/13285) which is a surge protected and internally fused CE approved transformer. This transformer itself with a TVS diode after it doesn't prevent EFT Common Mode ...
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Why is core resistance modeled to be parallel to the primary winding of ideal part of a real transformer?
When a real transformer is modeled to a simpler circuit, it is shown that the core resistance or a resistance model which basically describes eddy current and hysteresis loss is in parallel with the ...
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Why connecting two secondary windings together in an aiding dot-orientation parallel configuration will result in no output?
I need clarification on what would happen if the transformer is in aiding dot-orientation parallel configuration as shown below.
Would that be the same as connecting two batteries, in parallel, as ...
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Why would an in series-opposition center-tapped transformer not be used to drive a circuit?
I understand that if a center-tapped transformer is connected in series-opposition as in the image below, there would be no voltage across both circuit terminals. But can the individual voltage ...
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Analogue Read in ESP8266 WEMOS D1 MINI is fluctuating
I am trying to read the current consumption of a light bulb (160 W) using a current transformer (5A/5mA) connected to the ESP8266 WEMOS D1 MINI analog pin.
I have put a 240 ohms burden resistor in ...
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Isolated flybacks in series to generate high-voltage [closed]
I'm considering placing isolated flyback converters secondaries in series such as the image below. I want to drive the transformers individually using synced clocks (such each transformer has its own ...
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How to determine whether a transformer is dead
My range hood broke, so I took it apart. I confirmed that 125V is arriving at the control board, which is connected to a fuse which is good, which is connected to a transformer. My voltmeter (AC mode) ...
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Wurth transformer secondary pins on left and right side of transformer
I am looking to use Wurth Transformer 750310988 and I have noticed its pinout is very bizarre. My application is I want to float the secondary of this transformer up to 500VDC and provide a isolated ...
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How to measure flux in transformer in LTspice?
I wish to check the flux through a transformer core in my LTspice simulation. I have set up a push-pull converter simulation using a transformer with a turns ratio of 1 : 1.1, a supply voltage of 12 V ...
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Isolation transformers and short circuits
For some quick background and info: I'm a relatively fresh (~2y/ experience) EE in the solar field. I work in the R&D department of my company. My country operates in a 230/400V 50Hz grid.
We are ...
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How to add LED array to 110VAC AC circuit that includes small motor
I'm building a small machine that uses 110 VAC to power a small (14 W) motor. I want to add an LED array that a switch activated by the motor turns on and off. (The motor will also be gearing some ...
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Problem acquiring B-H curve
I'm trying to acquire the BH curve of a toroidal current transformer in saturation, having the primary and secondary current.
The formulas I am using are:
B = (1/NsS) Integral(Vs(t)dt)
H = (Ip*Np)/l
$...
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Is there a way to tell if I have MLV or ELV transformers driving my 12V 50W LEDs? [closed]
Is there a way to tell if I have MLV or ELV transformers driving my 12V 50W LEDs?
I want to dim a small row of ceiling downlights with 3-Way Lutron Maestro dimmers. The actual fixture is a Nora NL-301 ...
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Placing a comparator below a transformer
I am working on updating an older flyback design. Part of the update is adding a comparator to control a relay through a MOSFET. It's a quasi-resonant flyback so the operating frequency swings between ...
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How to deal with one inductor coupled with two different inductors?
I'm fairly confused on how to deal with this type of a situation. I can easily solve circuits with one simple coupled inductor, but this case is obviously different. The task is to solve for the ...
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Can I convert a step down transformer to step up? [closed]
I have a center tapped stepped down transformer 12-0-12 240 V.
I need to convert it to a step up transformer 12 V to 240 V and I need it to be centre tapped.
I am making an inverter circuit to convert ...
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1950s Era primary and secondary low voltage intercom system [closed]
I have a 1959 low voltage panel right next to my 120 volt panel in my laundry room.
This panel controlled an Old intercom system as well as the lights for the house.
Inside of the panel there seems to ...
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Identifying SMPS transformer
I have a SMPS acting weirdly and I believe to be caused by its transformer. I need to find a replacement but I'm having trouble identifying it.
The marking has too lines: 1st containing the VDE logo ...
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Flyback Transformer Winding Direction
Looking at the basic Flyback Converter Topology, the coupled inductor polarity should be opposite in order for the circuit to operate properly. However, I am confused on how to implement the correct ...
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Arc Lighter: Relationship between transformer inductance, oscillating frequency and energy of the spark
I'm building an arc lighter using YouTube videos as a reference.
This circuit from GreatScott worked for me.
I'm now trying to understand the relationship between the transformer inductance and ...
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Do Kirlian setups work with DC power? [closed]
I have been trying to build a simple Kirlian setup, and I've been trying to make my flyback transformer work, to no avail, so I shifted to use the small black 3.7 V to 400 kV transformers (as they ...
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Why does my flyback transformer simply refuse to work?
I've been trying to create a Kirlian setup like the one in a video by 'The Plasma Channel', and the flyback transformer for the power source just refuses to work.
I have a T1010A transformer, and I'm ...
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Dropping the line voltage on an HH Scott 265A tube amplifier
I have a pair of monoblock tube amplifiers that were designed to run on 117VAC. My wall voltage is about 121-123V.
What is the best way to drop the voltage down to an appropriate level?
Option 1: ...
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Simple forward converter - strange demagnetisation
I am trying to build a simple forward converter. After MOSFET turns off I am demagnetising to 100 µF cap on secondary side. There is about 1 µs core doing nothing and after that demagnetisation starts ...
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Is there a specific reason they wired the coils this way? [duplicate]
After dissecting the outlet side of the transformer and started unwinding the coil i realized they basically had 3 transformer in one. What I’m trying to understand is why they have it wired the way ...
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Confusion in number of turns and strands in flyback transformer
I am designing my own discontinuous mode flyback transformer and am following the book Transfomers and Inductors Design Handbook by Colonel. Wm. T. Mclyman. I have used all the equations of the ...
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How to tell how much current can pass through a transformer
Transformers have a ratio value. For instance, 10:1 will drop voltage 10 times less but increase amperage 10 times more.
Usually when shopping for transformers I see this voltage values for primary ...
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What transformer should I use for high power switching? [closed]
I'd like to build a high power switch mode power supply. I'm still not entirely sure how to do this, but I am playing around with some circuits for now.
My thoughts was to have input voltage (wall ...
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What’s the explanation on why the outlets wires are on the same coils?
Working on fixing a once upon a time good soldering station so I thought.
Inside the soldering station there’s two transformers, first one for the soldering iron that has an primary of 115 V and ...
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Transformer saturation value in volt-seconds
I have a slight confusion regarding the saturation rating of transformers. I often find this value stated in Volt-Seconds, which is a unit for the saturation flux, i.e. the maximum flux that the core ...
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Damage on Tesla Coil Secondary - is it ok?
I am building a small tesla coil (the OneTesla TinyTesla) and my secondary coil has some small damage. Is this damage tolerable as long as the wires still have continuity, or does it need to be a ...
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Problem solving faulty sodium bulb circuit
We have lab equipment at work with a sodium bulb.
The bulb is getting power but does not illuminate. Just a small glow.
Can somebody point to a possible cause of the problem? Or even just give me the ...
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What happens to the transformer output if the rated primary voltage is lower than actual reading from the wall socket?
If my transformer is rated 220VAC on the primary and my wall socket is reading 240VAC:
Do I get a "free" increase in secondary voltage?
If yes to no.1, by how much? Is this the correct ...
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Reverse Transformer For Smooth High Voltage
So I want to make a valve audio preamp, but need a way to generate clean high voltage DC for the plates of my tubes. I started with rolling my own boost converter which worked well, but was unable to ...
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Neutral grounding resistor
How does neutral grounding resistor in power generation side, see and link up with grounding fault at the secondary side of a transformer?
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Hot do I get this old phone to ring?
I’m working on a project where the ultimate goal is to have a button or switch activate a phone ringer. I found some old phone motors on eBay, but I have no idea what I would need to make them work? ...
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Continuous and discontinuous mode flyback Confusion
I was looking at the construction of the flyback transformers and found its two types the continuous and discontinuous mode. I have slight confusion regarding that:
Is the circuit designing of the ...
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Read transformer value and safety tips [closed]
I was trying to power up an old c64 without its original power supply, so i recovered a transformer from an old PC PSU.
Here's a top and a bottom view:
Up view
Bottom view
So I have a few Questions:
...
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Ethernet Magnetics Polarity Swapping
Can I on the same pair (for Example A) to swap polarity on opposite side of transformer/magnetics?
Update 1: Currently i use cross-over method to make lanes shorted and more easy to layout.
Update 2:...
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Should I use transformer + op-amp or only op-amp to amplify small audio signal?
I am trying to amplify a 10uV audio signal. This is easy enough with an op-amp, except that I need to make sure Vos is much smaller than the signal. 10uV is doable, but if I want to amplify much ...
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Flyback transformer with no load situation confusion
I am having a slight confusion in the no load situation of the flyback transformer. Consider the high pulse at the gate of the mosfet turning on the switch. At this case the current will increase ...
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Suggestion on core calculation with air gaps
I was working with the SMPS transformers and found a transformer that had a small air gap already there and was used in charging system of a battery. I wanted the ferrite core for my own transformer ...
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SMPS transformer power capacity and product of Area
I was working on the SMPS transformer and wanted to wind my own. For that I found the initial step of power calculation of the SMPS transformer. It stated to find the power using the products of area ...
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H-Bridge Class D Amplifier with transformer
I'm working on a H bridge amplifier capable to deliver 200 W into a 50 ohm load.
Supply is limited to 24/28 V, unipolar.
So I need a transformer in the output.
You don't see a filter because I only ...
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