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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Correctly Using the Chan model in LTSpice

I am trying to use the Chan model to better simulate a transformer in my design. When I am making an equivalent transformer circuit, where does the Chan inductor go? On the LTWiki it is implied ...
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46 views

How to read a transformer data sheet?

I have been trying to understand this datasheet but I think I am missing some core knowledge. I just want to know what the inductance of the primary is when the secondary is unloaded (I am using the ...
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326 views

Parasitic capacitance of planar pcb coil

As an experiment I attempted to make a planar PCB coil as shown below: Showing parts of a single layer for presenting detail. Together with a an EE ferrite core it generated 85mH of inductance as ...
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84 views

Eliminate reflections on pulse signal transformer

I am trying to isolate an RLC ringdown signal via an RF signal transformer but I'm having trouble maintaining the signal integrity through the transformer. Below is the simple schematic describing my ...
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85 views

What defines the maximum primary current of a (sensor-only) current transformer?

Take the Coilcraft CS1200L for example, which states the sensed current maximum is 35 A. This limit doesn't seem to be defined by the wire size which can fit through the hole (5 mm) as you can pass > ...
3
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2answers
1k views

Transformer to convert 220V split phase to 220V single phase

I'm a digital guy whose forgotten his "big wire" electrical education. I'm surprisingly unable to find a solid reference for this. I have a (European) 220V 50Hz split phase source (110V + 110V + GND)....
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3answers
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Questions about voltage drop at the transformer secondary and primary due to loading

Below there is an impedance matching aimed step-down transformer circuit where the primary to secondary turn ratio N1/N2=10. To actualize such turn ratio and voltage ratio, I set the inductor ratio L1/...
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506 views

Piezoelectric transducer impedance and phase measurement

I have a circuit comprising of LT1210 current feedback amplifier (supply voltage = +/-15V, gain = 4) and its output is connected to a transformer (RM10 N97) with N=16.6 (150/9) which is further ...
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797 views

What do these numbers mean on a transformer schematic?

What does the .7, .6, 1, .5, ...
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2answers
2k views

Transformer maximum voltage rating specifications

I don't know how to interpret the voltage values found in datasheets for transformers. For example, in the datasheet below: where it says 15v, 50mA near the winding schematic. Is this a maximum or a ...
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499 views

leakage inductance on three winding transformer

I have a toroidal 3 winding transformer. It's a step up, lets say 1:10 ratio, the secondaries are identical. If I measure the leakage inductance, shorting 1 secondary at a time, I get about the same ...
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1answer
100 views

Electric grid power transformer winding: If it is milliohms, why does 9V DMM show infinite ohms?

When testing large MVA power transformers, like 66kV to 16kV, the winding resistance in DC ohms is milliohms. It takes a high current supply to do this, then the V is measured across the winding to ...
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27 views

wave form of the diode current of a rectifier circuit and difference between the transformer and the AC source

So I have two questions I hope you would answer it, the first one is about how would the current Id of this circuits be? I mean his waveform. and my second question is these two circuits who are in ...
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315 views

How to ground a flyback transformer?

I designed a 50,000 volt power supply, that I am having problems with on grounding the HV side of the output. The HV appears to be injecting HV into my logic sections through the ground, damaging the ...
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0answers
49 views

How do I find Vs in this circuit with a 2:1 ideal transformer?

How do I find Vs given that V0(to the left) is 10L30degrees? I started by finding that the current on the 10 ohm resistor is 1L30 degrees, and then using kirchoff's law, the current on the tranformer ...
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Comparing inductances from LCR measurements and FEMM simulations of a simple transformer

I am trying to compare the results from a simple transformer using two identical Wurth Elektronik inductors (Reference 760308102308, datasheet attached). I measured the inductance with an LCR while ...
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160 views

Relation between primary current and secondary currents in a transformer with multiple outputs

This applies for a flyback converter working in DCM. Here is what the following document (https://www.infineon.com/dgdl/an-1024.pdf?fileId=5546d462533600a401535591115e0f6d) has : Here is what I ...
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250 views

Understanding SPICE code in Chan Transformer in LTSpice

Taken from here: http://ltwiki.org/?title=Transformers I am having trouble understanding how the Chan core is actually linking in with the coils. Does anyone understand what the SPICE code is doing ...
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127 views

What causes voltage to increase from 12V to 36V as specified?

Reference article and paragraph: Relays, Selection & Usage (Part 1) - 8 - Latching Relays ...
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0answers
347 views

Why should the primary winding of the transformer not be grounded?

I've been wondering what would happen if you grounded both star points of a Y/Y connected transformer. This shouldn't affect the voltages, so why really is it not advised to earth both the primary ...
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61 views

Which capacitor in series with resistor circuit to reduce remanence effects of transformer?

The "Comparative Analysis of Mitigation Techniques for Inrush Current of Transformer" mentions "Pre-insertions resistor with capacitor method" as an inrush mitigation technique: When circuit ...
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132 views

Startup and auxiliary/station transformer power parallel to bus

This question is in regard to switchyard/electrical distribution operations in a utility power plant. During a startup, the electric distribution system is lined up so that the startup transformers ...
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532 views

2 Switch Forward Converter Volt-Sec/Charge Balance

I am attempting to design a 2 switch forward converter. I understand how to do the volt-sec balance and charge balance when the converter is as shown in the ideal 2 switch forward converter below. I ...
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57 views

Equipment Grounding Conductors (EGC) Behavior of Autotransformers

I'm a bit surprised why some people in the US were alarmed about using autotransformers as general appliance 240v-120v step down transformers. In Asia where we use 240v. All 240v-120v transformer ...
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528 views

Flyback Transformer - Grounding the Ferrite Core

Today I dismantled (I hope this is the correct verb) a flyback transformer. The thing that I've never seen is that one end of one of the windings is "glued" to the ferrite core (Before you ask; yes, ...
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120 views

Flux control of transformer

Can the flux (not flux density) of a transformer be controlled so as to achieve constant voltage output with varied loads? For example, increasing the flux slightly when the load is high.
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42 views

Keep potential difference fixed for transformer's output

I have a source consisting of V1, R1, L1, and L2 to which my load R2 is attached: For the load, I have 10 or 100 Ohms. 1) R2 = 10 Ohms: Vrms = 315 V, irms = 32 A, P = 10 kW 2) R2 = 100 Ohms: Vrms =...
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1answer
590 views

MMF diagram, of a transformer - why layers are numbered this way?

i have found very interested concept for calculating losses in winding. The MMF diagram is required. i have found mmf diagram examples on coursera magnetic course and on a ridley engineering website. ...
2
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1answer
585 views

Find impedence given per unit value-transformer

I really can't wrap my head around this. Three single phase transformers are connected to create a 3 phase transformer. They all have the same nominal values : voltage conversion : 1.2kV/120 V (...
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131 views

Transformer test only making sense unloaded

I have a problem in testing a transformer recovered from an old wall wart. The transformer has several secondary taps: the wall wart had a slide switch allowing the selection of four different dc ...
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343 views

What will be the effect of putting a single phase load on an open delta transformer secondary?

Suppose I have an open delta transformer, 240 line to line secondary. I have a single phase constant power load I want to apply. I could apply it across either of the 'closed' phases and load that one ...
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45 views

Transformer's capacitance

Our main purpose is create the transfer function of a transformer, and we want that for a resonance frequency higher than 1 MHz for our LLC transformer in an LED project. https://www.omicron-lab.com/...
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76 views

step-up transformer design - basics

I want to step up Li-ion battery voltage to ~100-125V at ~145kHz and ~0.5Arms. (The circuit is to drive a small piezo at its ultrasonic resonant frequency.) I have limited space. Are there any rules ...
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47 views

Uneven Brightness Curve When Using Digital Triac Dimmer on Neon Transformer

I am working on an AC dimmer project using the following circuit: This circuit functions by detecting zero crossings in the AC power input via the LTV814 optocoupler connected to a pull-up input pin ...
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65 views

Resonant Transformer / Resonant Inductive Coupling

I´m trying to build a resonant transformer (or a resonant inductive coupler, I don´t know if the names fit to the topology I´m showing, anyway). The idea is to develop a high voltage on a capacitor. ...
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34 views

Transformer core (eddy + hysteresis) losses

The question is: The solution is: However, Transformer core Losses For Eddy current losses I think they will not change. For the Hysteresis losses the flux is raised to a power greater than 1, so, ...
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1answer
135 views

How do I calculate the maximum load on a center-tapped AC/AC transformer for a bi-polar linear power supply with full wave rectification?

I have a 24 VCT AC to AC step-down transformer, which has three wire leads on the secondary. I'll call the secondary leads X, Y, and C, where C is the center tap. With a DMM, the voltage between X and ...
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1answer
74 views

Half-bridge transformer driver capacitors overheat

I'm trying to build a DSP plasma speaker using IR2104 half-bridge to drive a TV transformer. The switching frequency is between 15KHz-100KHz. I chose the topology from an old analog plasma speaker ...
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52 views

What is the effective value of the current of the voltage generator?

I need help with this task, if anyone had a similar problem it would help me. The task is: A voltage generator is connected to the primary of an ideal transformer, transformation ratio n rms values ​​...
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28 views

How to match Transformer output Impedance for Ultrasonic Cleaning Transducer

I have a transformer outputting the 240VAC 40kHz. The Transducer is 50W, 4100pF, 10-20 Ohm at resonance, ~40kHz resonance) The Secondary of the transformer is 12mH. I am trying to match the impedance ...
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1answer
125 views

DC AC Inverter topologies

I am trying to get a deeper understanding of sine wave inverters (like this one) and thereby came across different topologies like a Push pull inverter with a center taped transformer or a full bridge ...
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43 views

Primary Current in a Transformer

In the image attached above, the book uses I2 = V2/Z2. However, the question says "primary is excited by 200V". So, V2 should be 100V. Is the solution wrong then. Question for reference: ...
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127 views

Confusion of the working principle of Isolated SEPIC converter

I am a bit confused about the current flowing in the magnetizing inductance L_m when the switch is off. I am reading a book(Erickson & Maksimovic, Fundamentals of Power Electronics, 2020), ...
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27 views

What determines the frequency of a ZVS driver

Schematic of ZVS driver Output waveform of transformer Determining frequency from time difference between peaks of output waveform at secondary coil of transformer I was simulating a ZVS driver in ...
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77 views

Autotransformer equivalent circuit

I am trying to find an equivalent circuit for autotransformer. But there is no any source about it. I tried to solve something about it. Can anyone have any idea about it?
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49 views

Would it be possible to power an X-Ray tube using a Marx generator?

To the best of my knowledge most X-Ray tubes are powered by a smaller voltage running through a large transformer to step it up into the magnitude of 10-100 KV. This larger voltage is then pulsed ...
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145 views

Diy arc lighter

I am trying to make an arc lighter, tried rewinding primary of ccfl transformer/inductor with only few turns and made my own with inductor I got from cfl circuit, they all worked fine for some time ...
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43 views

How to generate an underdamped oscillation using transformers?

We want to generate an underdamped oscillation with a transformer, with this circuit: I am able to generate this signal: But I want to use a transformer instead something like this: What should I ...
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0answers
44 views

coupling coefficient & effective turn ratio

In the fundamentals-of-power-electronics this book, Chapter 13 Transformer Modeling How to derive the coupling coefficient (13.52) & effective turn ratio (13.51) I can use the ideal transformer ...
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1answer
177 views

i have problem with capacitor discharge ignition circuit CDI

i have a hard time to understand what is the problem in this circuit, can someone help please, i have a Moped with its capacitor discharge ignition Box work fine, the spark exist, but i wanted to make ...

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