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.

learn more… | top users | synonyms

1
vote
1answer
26 views

Three phase balanced transformer network with b-phase fault

100 kVA, 11 kV (delta) : 400 V (wye), Xeq = 0.1 p.u with a neutral to ground connected through Zn = j0.1 (ohm) I have a question where the above transformer is fed by a balanced positive sequence ...
1
vote
1answer
26 views

Modelling grounding reactor as transformer

First: This is not a question about electronics, it's about large (three-phase) power systems where the components have ratings in kV and MVA. I'm mainly interested in symmetrical components, and how ...
0
votes
1answer
32 views

Magnetizing current in switching converter

I have a question about the magnetizing current in a forward switching converter (image from "ON Semiconductor: Am improved 2-switch forward converter application"). From the picture it looks like ...
0
votes
1answer
75 views

Three questions about the use of a transformer in switching power-supply

In this document (an introduction to switching power supplies) a boost-mode switching power supply is presented: it has a simple inductor, diode, capacitor and load. Then (page 9) it is specified that ...
1
vote
0answers
37 views

Flyback Transformer Active Snubber Design

I'm using a flyback transformer along with the LT3750 controller by Linear to charge a capacitor. I'm wanting to increase efficiency and improve the circuit. I began with looking into an RC snubber to ...
1
vote
1answer
31 views

centre tap transformer 240V ā€“ 24V @ 250mA

I have a centre tap transformer 240V ā€“ 24V @ 250mA. I know I will get 12V between the centre tap and either of the other connections (I think one will be -12V), but will I have two 12V supplies at ...
0
votes
1answer
90 views

Make stun gun with Arduino as oscillator

    Hello. I've noticed that for creating "sparks" with an transformer I need an oscillator. I want to know if I can use arduino for this. I'm afraid of breaking it because of the ...
2
votes
2answers
67 views

Transformer hum - DC offset? Does this cause transformer breakdown?

I have an integrated amplifier that I like, but it hums - it's an Arcam A22 and contains a big toroidal transformer. It sits on the desk right next to my monitor and I can't live with it. I just ...
0
votes
0answers
16 views

What kind of setup and components are in this and how does it work. Also, where can go and find the parts to buy? [duplicate]

This is a sound system I am trying to recreate. It has a 5v fm/bluetooth module on the top of it with a switch to turn on and off.It then runs to a Ceiling speaker with some sort of motherboard in it ...
0
votes
1answer
53 views

Transformer Current Limiting

I Rewired A MOT (Microwave Oven Transformer) To have an Output of 40V and a center Tab With No load the primary Gets HOT really fast. I measured the current draw with no load and it pulls about 10 ...
-1
votes
0answers
32 views

Charger failure safety measures

Suppose I use a charger to power a circuit and suddenly a component inside fails and the 220 volts can easily reach my project,flowing trough the now broken charger.What can I put between the charger ...
0
votes
0answers
24 views

Transformer characteristic for impedance matching in RF

In an rf impedance matching circuit it is assumed that transformer is ideal or large enough. I just wanted to know the quantification of "large enough" (which parameter is large with respect to what)
4
votes
2answers
64 views

Concerns with running a transformer at frequencies greater than what is specified?

My office has a few of these (http://www.hammondmfg.com/182.htm) and I came across a circuit which are driving these up to 5KHz. To my knowledge, the circuit worked and has been used in the past ...
0
votes
3answers
79 views

How to convert 220V AC @50 Hz to 400V @ 20KHz?

Sorry, I may be asking simple question but I'm not specialized in electronics. What I want to do is to increase the voltage from 220V AC to 400V AC. Also I want to increase the frequency from 50Hz ...
0
votes
1answer
91 views

How to infer pinout and winding ratio of this transformer?

Hi, I pulled this transformer from an EL wire inverter and am trying to figure out how to infer: Which pins correspond to the primary and secondary coils The ratio of the windings Any other ...
0
votes
0answers
40 views

Why does the primary inductance go to zero when the secondary is wound?

I am making a transformer for a strobe circuit on a ferrite core. The primary is 10 turns. When I wind this I see an inductance reading of 0.30mH. I then wound the secondary of 200 turns. This ...
0
votes
1answer
70 views

Noise Matching transformer

I'd like to use a transformer to improve the performance of our SR5184 preamp. The signal recovery SR5184 is an ultra low noise preamplifier. It has 0.8 nV/ āˆšHz input noise and a bandwidth of 0.5 Hz ...
1
vote
1answer
63 views

Trying to determine if transformer is safe

I am building a switching power supply with an isolating step-down transformer. Part numbers: Controller: LT3798 (http://cds.linear.com/docs/en/datasheet/3798fa.pdf) Transformer: 750312872 ...
0
votes
1answer
27 views

Long Term effects of saturating isolation txfr

I have a 1:1 isolation transformer that's rated for 25VA. I'm consuming 30VA, 20W. I've noticed because I'm saturating it, the txfr is no longer 1:1, it's more like 1:1.1. Other than this issue, for ...
0
votes
1answer
77 views

Why is Rack Mounted Step-Up Transformer Not Industry Standard?

I'm tasked to source a 1U step up transformer so that customers with only 120 VAC mains power can utilize 240 VAC for our products. I've contacted TrippLite and APC who both offer a 2U (2 rack unit) ...
0
votes
0answers
30 views

delta-star three-phase transformer for single phase

Can a delta-star three-phase transformer be used with a single-phase supply and load without damaging it? simulate this circuit – Schematic created using CircuitLab Primary: star/wye ...
0
votes
1answer
39 views

12Vx2 2Amp Transformer

Please Help me I have edifier woofer x600 and 12Vx2 2 Amp Transformer (Power Supply) is placed in it. The Problem is that i want to run my woofer system on 12v battery. // The transformer has two ...
1
vote
2answers
66 views

The \$I^2R\$ loss in transformer is eddy current loss or copper loss?

As the title say, this is what my text book say. I use Hughes Electrical Electronic Technology 10th edition The varying flux in the core induces e.m.f.s and hence currents in the core material. ...
0
votes
1answer
50 views

Question about output current

I've got huge three-phase transformer, primaries are connected in Y configuration, secondaries in Delta, then goes to 6 diode bridge rectifier. Output is about 200 amp 52 VDC. In short, how many ohm ...
0
votes
1answer
43 views

DC Thump-like noise with Isolation Transformer [closed]

I put an isolation transformer inline with my audio (unbalanced 2 channel audio; with L, R, signal Ground). It still makes noise when plugging the auxiliary cord in (kind of like 2 thumping noises) ...
3
votes
2answers
100 views

When/where to open and close a transformers output

I came across Beware of Zero-Crossover Switching of Transformers (TE Connectivity App Note) where they discuss about how you shouldn't switch a transformer at the zero crossing because it would have ...
12
votes
5answers
1k views

Can a transformer work if the core is not circular?

I am trying to build a transformer to convert 12V AC power to 5V AC. Here is what I have right now: I haven't adjusted the coil ratio yet but I tried it just to see if there would be any output ...
0
votes
1answer
30 views

Reading Current Transformer using Arduino

I want to be able to read current using an Arduino. I have purchased a Hobut Current Transformer from Farnell (Element14): ...
0
votes
1answer
48 views

What is the difference between a magnetized nail and a coil?

When I was a child, I brought a nail (metal bar) and I made some turns around the nail. It was something like a coil and the nail was the core of that coil. When I applied DC on the coil using 1.5 V ...
0
votes
1answer
70 views

Why is there a copper winding isolated from the iron core of my transformer?

Here is a picture of a 1970's arc welding station. There is a 9 inch bar of metal surrounded by 88 windings of 4mm copper, that used to be on the end of the secondary winding, which is made up of ...
0
votes
2answers
119 views

Why isn't a transformer a short circuit?

I'm a newbie with electronic components and I never fully understood why transformers, while essentially being a short-circuit from a wire perspective, don't act like short circuits (i.e. they don't ...
0
votes
1answer
55 views

Reduce voltage after AC-DC rectification before step-down

I have a Weller Magnstat soldering station providing 24V AC to the tip. I want to use that output to power a 12V fan to disperse or absorb the fumes. With a cheap multimeter I measured 25V AC during ...
0
votes
1answer
61 views

Way to get high voltage from a watch battery

I'm creating a vary small device that need an high voltage around 50v. But because the device is really small like a pistol bullet, I can only use very small batteries like watch battery or button ...
0
votes
0answers
26 views

Modifications to Neon Sign Transformer to turn it into a variable DC power supply?

I would like to turn a neon sign transform into a DC power supply. Looking into this it would appear I need some rectifiers to turn the AC output into DC. I could use a variable resistor to adjust ...
1
vote
1answer
61 views

thermal knife power supply (part 2)

This is "part 2" because my original question has only brought up more queries that i am unable to solve. The first part can be seen here for any who are interested: "Hot-knife"/Thermal ...
0
votes
2answers
54 views

Transformer temperature rating

I'm building a power monitor (so I get notifications if the power is lost in one of the inputs). To monitor it safely, I used these 220/12 0.35VA transformers ...
0
votes
1answer
56 views

tube amp power transformer

I am trying to build a 18w amplifier based on this schematic however my power transformer doesn't have a center tap on the secondary winding Is it possible to use this power transformer for this ...
0
votes
0answers
47 views

Parallel operation of transformers

In a firm, two 250 KVA three phase distribution transformers (primary connected to same commercial line) are connected to different bus bars for feeding load. A bus coupler is also there with castle ...
0
votes
0answers
38 views

Transformer specifications to get 40V ac output from 210-250V ac in Proteus simulation

I want to design a transformer that connects to the ac main in proteus, steps the voltage down, and gives an output voltage of approximately 40 V. The core is made of f-type plates. The primary ...
1
vote
2answers
62 views

Impedance matching audio transformer windings

I want to create an isolation, impedance matching, balancing transformer for a DI box. I want it to work on Audio frequency and use a toroidal ferrite core. The input is an electric guitar, so it ...
1
vote
1answer
56 views

Toroid Core Selection for Audio Isolation Transformer

I am a newbie. I have attempted to make an isolation transformer with some toroid cores and it worked, but not well. I tried using a "wide band" toroid core and it seemed to have killed a lot of the ...
2
votes
3answers
234 views

“Hot-knife”/Thermal cutter power supply design

Im undertaking a DIY rope cutter project to avoid paying for the ~$150 storebought ones. Many resources online told me to use a light dimmer + transformer configuration and i had planned to go a step ...
0
votes
1answer
85 views

Old Radio RF Transformmers [closed]

I want to make a TV transmitter (http://electronics-diy.com/electronic_schematic.php?id=851). There is an RF transformer on it (T1:4.5MHz 1F-can-style RF transformer) that I want to find it from old ...
1
vote
2answers
84 views

How do I identify the imput side of a transformer

I have this 2.5VA Split-Bobbin Power Transformer 115/230VAC. According to page 3 of the Data Sheet (PDF) it looks like there is a line on the "DSW" version on the pin 1-4 side. This seems to ...
0
votes
1answer
65 views

Powering a Futaba S3003 servo

I'm working on a project and I need to use a Futaba S3003 servo, I'm about to buy a transformer that gives 6v, the thing I'm not sure about is the amperage. Is this transformer ok? I can choose 3V, ...
1
vote
2answers
89 views

About “leakage inductance”

I'm a little confused about the transformer "leakage inductance" for days. Per this text book, it gives a schematic view of fluxes flow in the transformer: It's apparent that the two leakage flux ...
2
votes
1answer
48 views

About the leakage reactance of transformer

As known the transformer's equivalent circuit can be developed as below: Assume the \$V_{1}\$ is the voltage applied to primary side, and \$V_{2}\$ is the voltage developed at the secondary load. ...
2
votes
1answer
49 views

Transformer Efficiency Issue

Trying to improve on the transformer efficiency, I changed the configuration of the rectifier from half wave to full-wave. Below shows the configurations I used Transformer turn ratio is enough so ...
2
votes
2answers
543 views

transformer has continuity but no voltage output?

I have two old transformers that appear to be fine, however no DC voltage was measured on the secondary coil. I have measured: The input voltage: 229 AC the input coil ohms: 0.015 kOhms the two ...
-1
votes
1answer
55 views

Confusing transformer winding, what is it and can i change it?

here are two 380V to 24V/48v transformers that weigh 10 pounds each. I was hoping i could get 15V with 500w out of one at 240V and measure the welding potential. the secondary winding uses 0.5mm ...