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.
3,934 questions
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How to Calculate flyback transformer primary and secondary number of turns and turn ratio?
I try to design SMPS converter with flyback converter topology.
I can find right value of flyback transformer. For CCM, what is the equation for calculating primary and secondary number of turns & ...
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Confusion regarding Secondary Current Direction and Lenz's Law on a Transformer
I am trying to understand the exact mechanics of secondary current induction, specifically the direction of current when the primary winding begins to conduct. I have found conflicting diagrams online ...
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Self-built flyback not operating as intended - output voltage too low
I have built a ETD44 flyback with 11 turns on the primary and 144 turns on the secondary. I am using 0.75 mm paper as spacers and the core material is PC40. The diode on the output side is a FEP30 ...
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Where can I buy these small heating device for mist [closed]
It’s a part of a electrical heater whit a misty smoke from the water reservoir, this part is heating the water up. The heater called ruby
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High Voltage Shock Safety in Electroadhesion
I am working on an electroadhesive for a project this year, and I need to find some sources that I can cite for the safety of the high voltages involved.
The high voltage converter that I was going to ...
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Direction and Orientation of Current in Transformer
I'm using this current transformer to measure AC current in my application through a metering IC. This input from the secondary of the current transformer goes to a differential ADC in my metering IC.
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Clipping waveform before the full bridge rectifier: What could be the reason?
I have a small audio mixing console which is supplied by ±19 V AC from an external transformer. The transformer started making a buzz sound, so I opened it up (because it was also much easier to start ...
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Discrepancy Between LTSpice Simulation and Real Measurements
I have designed a circuit that we use in practice, and it works correctly in real life. we connect J2 to microcontroller to monitor the current in primary side. it is working so good in practice. I ...
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$3 Aliexpress 12V 3A Adaptor
Impulse buying. While I don't expect it to pass the safety best practices nor the cleanest 12V, I have to be sure what I bought is not going to burn down the house. :)
Still learning Elec, but as far ...
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Understanding circuit that produces a sound that alternates on and off
I am new to electronic engineering. I bought the Elenco 130 playground as I prefer to learn through practice. I am also reading a book called Teach Yourself Electricity and Electronics.
I opened the ...
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Trying to limit the current going through a transformer coupled to a Piezo Speaker. Why is the speaker louder using an Saturated NPN transistor?
I'm working on a project where I need to update an existing design to resolve an issue with the audio amplifier circuit overheating when the volume is set to HIGH. My approach was to replace the NPN ...
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Power Transformer Won't Step Up Voltage
I am currently trying to use a large Class 2 Non-Inherently Limited Power Transformer (specifically Triad Magnetic's VPP24-2330) in a DC/DC flyback converter. However, the transformer doesn't appear ...
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How can we determine the load on the secondary of a transformer in order to achieve nominal current on it?
I have the following question:
How can we find the Load that it must be connected be on the secondary in order to achieve nominal current on it?
My solution is the following:
By applying KVL:
$$VphA = ...
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Why is the power loss in an inductor less than that of a transformer of equivalent inductance by an order of magnitude?
I tested two inductors and two transformers close to 1 mH and there was very little power loss in the inductors when driven by a square wave and yet the transformers had significantly higher power ...
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Why does my audio transformer step up voltage but not drive my headphones loudly?
I'm experimenting with audio signals and a transformer, and I'm confused by the results.
My Setup:
Source: My Android phone (Itel A25) playing a music audio file at maximum volume.
Measurement: My ...
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In a 3-phase transformer, why don't the windings induce voltages on the other phases?
I suppose I have a poor understanding of the physics behind magnetism. As I understand a basic transformer to work - the primary winding produces a flux on the core which induces a voltage on the ...
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Current sense transformer
This is an RF current sensing circuit with a 1:100 (Primary:Secondary) transformer.
I want to derive a formula to calculate the current flowing through the primary circuit. I have written some ...
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How do I connect a PLL sensor on transformer output with two secondary windings to a diode rectifier load?
Background:
I am working on a project of modernizing a system for a lead acid battery charger. I will do this with a Vienna rectifier, that needs the current angle, that I get from a PLL, for control.
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How to properly ground and protect a 240V EV charger circuit fed from a 480V 3-phase panel via single-phase transformer?
I’m installing a 240V, 40A electric vehicle charger that uses a standard NEMA 14-50 plug. I only have access to a 480V 3-phase panel, which has sufficient capacity to power the charger.
After ...
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Best Topology for 300V - 1500V Input and 220V Output DC
I’m designing a flyback converter with a 1500V max input and ~220V output. The main issue is device limitations: a conventional flyback would need a MOSFET rated above 1500V, but most available ...
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How to design a transformer
What electrical quantities are to be found while designing a transformer whose power in kva and only input output voltages are given? What electrical parameters are to be found and what is the ...
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Why can't I get the magnetizing inductance across tertiary winding in a forward converter?
As per the standard magnetics theory, the magnetizing inductance (of an ideal transformer) can be placed across any winding. (Ref the accepted answer for this StackExchange question.)
Let me try ...
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LLC resonant converter "calculation"
I am working on an LLC resonant converter design,
Lm = 490 µH,
Lr = 90 µH.
My next step is to design the transformer. Could someone explain:
What type of transformer is typically used after the ...
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Do planar transformers need insulation between core and PCB?
There are multiple construction options for planar transformers. They can be implemented with separate small PCBs or integrated into the main PCB. They can be clamped or they can be glued as ...
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Radio antique audio transformer DIY?
Good evening,
Is it possible to recreate this small audio transformer at home. There isn't enough information in the schematic is there??
Thank you for any guidance.
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Single wires on a secondary transformer?
I am working on an old guitar amp (converting an Ampeg VT 60 to a Fender Bassman), but want to bring down the voltage. Working on bucking the AC using the 40v secondary (purple to green), but confused ...
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Can the transformer cited below be used as a plate transformer for two 4-1000A vacuum tubes for amateur radio service
The 4-1000A tube needs a plate voltage around 4 to 6k VDC and a current around 1.25 amps. I have a pair of tubes. My question surrounds the plate transformer. I have found a control transformer that ...
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Transformer(less) power supplies substitute & transformer selection
Ok peeps, this is not a discussion of the safety or advantages/disadvantages of Transformerless Power Supplies (TPS) as there are many on this QA already. Rather for those who have already decided to ...
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Reverse-engineering this electric flyswatter circuit
I recently disassembled this electric flyswatter, and am having trouble turning the PCB into an accurate circuit diagram. I think my diagram is not far off, however I am having trouble understanding ...
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AB Amplifier driving a transformer looking like a short?
I am attempting to design an analog sine generator that should create a low voltage 60Hz sinusoid, amplify the voltage to around +/- 15V and then use that signal to drive the primary of a step up ...
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Identifying current transformer ratings (CT 1D04.1)
I've found this current transformer in some junk and would like to use it for a little project, but I'm having difficulty identifying the ratings on it. I haven't found other CTs with labels like this ...
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LTSpice simulation "stalls" due to convergence problems when simulating transformer + bridge rectifier
I have the following circuit where the transformer has two independant secondary windings and is modelled with perfect magnetic coupling between all three windings. The only "parasitic" ...
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PWM signal delay (distortion) at transformer
The transformer (Mfr.Nr.: PH9400.111ANLT) is causing a delay of about 50ns on this 150KHz, 3.3V PWM signal.
Are there hints to deal with this delay and distortion? This signal (S1) is driving a MOSFET ...
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PoE center tap vs dedicated V+/V-
I am using a 10/100 PoE RJ45 jack with integrated magnetics. The datasheet is quite sparse as is to be expected from LCSC... I am just trying to understand why the data sheet shows the part exposing ...
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Selecting a replacement SMPS flyback transformer
I'm trying to repair the PSU in a TV and need to replace the transformer. The part is a YUVA 80GL52P-10-N and the primary winding is open circuit. I've tried searching for a replacement and contacting ...
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Using a transformer gate driver for MOSFET. Can back EMF breakthrough the gate and how the back emf is looks like in this case?
To reduce time of MOSFET switch , we need as much current as possible and recommendations says it can be like 5A.
So, if i make a transformer with proper driver to provide a 5A - 15V on secondary, it ...
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Why don't transformers used for impedance matching cause reflections?
Original question: I understand transformers are often used for converting impedance, for example the secondary feeder loop on a loop antenna. However what I can't get my head around is why ...
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Math behind building a Custom transformer
Trying to build a step up transformer that takes in 0-120V pulsing dc and steps it up to 20kv with a max secondary current draw of 3mA. I will be converting Maine’s voltage into the DC using a full ...
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Why use a 1000:1 transformer instead cascading three 10:1 transformers?
I was researching different ways to make a high voltage DC-DC power supply in the 20 kV ~ 30 kV range, with output of a few tens of micro amps. The purpose is for testing isolation and resistance to ...
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Using LAN transformers as generic pulse signal transformers - how to estimate max. flux
For passing PWM signals around in an isolated way, I want to consider LAN transformers, because they are cheap and ubiquitous. The schematic below shows the circuit conceptually. Here is a link to a ...
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Why some step-up audio transformers give no output?
Maybe you can help me understand this:
I have a situation like in the diagram below (excuse my poor drawing skills..), where I have a very small current small voltage signal in the audio frequency ...
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Limitations of ferrite cores at low frequencies
Might sound like a silly question but I was reading on transformers:
What causes ferrite cores to be less suitable for transforming voltages at low frequencies (say 50 Hz) compared to iron cores? And ...
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Using small transformer for large generator
There are 12 transformers used in MATLAB's IEEE 39-bus system example, and every single of them is rated at 100 MW apparent power (default value) even though they are connected to generators having ...
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What is a Yy+d transformer?
I came across this term in my notes. What is a Yy+d transformer? I am familiar with Yd,Yy,Dd and Dy.
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LLC transformer Design
Recently, I encountered a question regarding transformer design, and I would appreciate your advice. I am currently designing an isolated switching power supply, specifically an LLC DC-DC converter. ...
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How to measure AC resistance of a transformer using LCR meter?
Say I have a high frequency SMPS type of transformer. I want to measure its AC resistance using an LCR meter. The LCR meter will give an AC resistance reading, but as I understand it, the AC ...
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Need help understanding PoE Magnetic
This is the magnetics connection in my design. This PCB circuitry has been tested and working individually, but when I connect two or more of the same PCB hardware to an ethernet switch, the ...
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Anyone tried small transformer to apply drive to the upper or highside? MOSFET in push pull so can use 2 N-channel MOSFET rather than a P-channel
Anyone ever tried small transformer to apply drive to the upper or highside? MOSFET in push pull say for a square wave oscillator so can use 2 N-channel MOSFETs rather than a P-channel Is it really ...
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LED transformer not giving output till LED load connected [closed]
I have a LED transformer that connects to mains 240 volts and is supposed to drive LED lights. I want to use the transformer to drive a solenoid valve that takes 12 volts at 500 mA.
The transformer ...
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Why is eddy current loss represented by a resistor and hysteresis loss by an inductor in the equivalent circuit of a transformer?
I am studying transformers and have learned that core loss happens due to eddy current and hysteresis loss. Below, I provide the equivalent circuit for a transformer.
Here, $$R_c$$ represents the ...
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