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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47 views

What's the thick wide aluminum tape used for in last mile grid transformers?

This YT video (scrolled to 0:45) shows the process of fabricating a pole mount transformer. At 0:45 the following is shown: there's a wooden brick used to hold everything together, it's covered in ...
0
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1answer
50 views

Wiring a step down transformer

I have a Transformer with the following writing on top of it : TFM-00053 CLASS B 130°C Z150H E154515 LEI-4 8B25 it has three thick wires on one end : Blue Brown Red ; the resistance ...
0
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2answers
44 views

Voltage on the secondary of current transformer

we know that current transformer is used to step down the current of the primary side. So basically it is a STEP UP transformer. Also we say that current transformer basically works on close to short ...
-2
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0answers
19 views

current transformer and potential transformer difference

Is there any operating principle difference between current transformer & Potential Transformer ? If not, what is the difference between them?
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1answer
30 views

How to measure ratings of a transformer

If I am given a transformer without any datasheet of it. Then how can I measure the maximum current and voltage rating of the transformer?
1
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2answers
32 views

Can a planar transformer replace a laminated transformer for 50Hz AC conversion?

I have seen planar magnetics transformers even with isolation up to 20 kV. However those devices seem to be designed for DC/DC conversion in 100 kHz range. I am wondering whether low frequency ...
0
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1answer
57 views

D.C power supplies, regulated linear power supply question

Design giving the necessary ratings and characteristics the necessary for the transformer, bridge rectifier capacitor and regulator , a 12v , 2A regulated power supply . the available mains supply is ...
-4
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0answers
50 views

D.C power supplies , necessary ratings and characteristics question [on hold]

Can anyone help me with the question please ??? Design giving the necessary ratings and characteristics the necessary for the transformer, bridge rectifier capacitor and regulator , a 12v , 2A ...
0
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1answer
33 views

Voltage transfomer without ground connection

today i bought a transformer 200v to 110v for my soldering station hakko fx-888D however it doesn't have a ground connection. Is there any problem if i connect the soldering station to it?
0
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0answers
45 views

Wireless powered power line robot

I'm trying to make a small robot with a camera that can run on a hanging wire outdoors. I've been thinking of ways to power it such that I would not need to pull a tether around, need to recharge ...
0
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2answers
56 views

What is the best way to serve AC power to a 12v - 5v DC regulator with 1Amp current?

What transformer should I use to supply AC voltage in a circuit which is using 7812 and 7805 - Positive Voltage Regulators. I need approximately 1Amp current. What is the best way to minimize the ...
0
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0answers
24 views

Angles of phase displacement between phase and line voltages in star connected transformer

I recently did a lab in class which required using an oscilloscope to measure the phase difference between the line and phase voltage of a star to star connected three phase transformer. Two of the of ...
0
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2answers
176 views

How to position adjacent transformers so they don't interfere?

Using a couple of 240V mains step down transformers, undecided whether to use E/I laminated or toroidal, one 22VA the other 7VA. How to mount them in the case, so that they're not affected by each ...
0
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1answer
55 views

Shorting leads on centre tapped transformer

I have an audio transformer (SP-66) with a 1:1 ratio and centre taps on the primary and secondary windings. Tests: When I input a 6.5 kHz 8 Vpp sinusoid on the primary (pins 1 & 3), I observe ...
2
votes
1answer
58 views

What type of transformer would be required to boost a voltage signal by 2?

In books, everything is theoretical and if you want to boost your signal up by 2, you get a 1:2 transformer. Great. However, in the real world, there are different types of transformers which I think ...
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0answers
65 views

How can I charge an 18V drill battery off of a 12v solar system

I have a small solar setup that runs on 12v. I'm interested in charging my 18V drill battery. I do have a power inverter, so I can plug the drill charger into the power inverter, but my concern is ...
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1answer
46 views

If you want to test a step-up transformer, must the load resistor equal the source impedance?

Ideally, do you want to add R1 to balance out the impedance so you get an accurate reading? simulate this circuit – Schematic created using CircuitLab I'm trying to find out the turn ...
1
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1answer
51 views

Can I Use Current Sensing Transformer Instead of Power Transformer

This is a follow-up on this question: How to Design Arduino Voltage and Current Sensing Shield Thanks to user bigjosh, I read the article: ...
0
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2answers
77 views

Powering nichrome, possible to do it with AC?

I am working on making a little nichrome-tipped pen for wax welding and planning to use a benchtop supply to provide the small amounts of DC needed to heat up the wire. Figuring out the right power ...
0
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2answers
48 views

Flux in transformers

I have found it very difficult to find what actually happens with primary and secondary generated flux in transformers, I understand the normal transformer theory but it doesn't add up in reality! I ...
1
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0answers
40 views

IF transformer color codes

Is there any standard color code available for IF transformers? Generally in most of the Japanese radio receivers I see red color slug for MW oscillator, white and yellow slugs in AM IF stage, ...
0
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1answer
59 views

protect A transformer from a DC voltage

In may project I input a AC voltage to a transformer, the same input may have DC voltage, so i am searching for a way to disconnect the transformer form the circuit ,like a AC detection circuit to ...
0
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0answers
55 views

Need help creating electric shocker

I'm trying to make an electric shocker (prank buzzer, taser, whatever you'd like to call it) for a Physics project from a disposable camera. The one we're using is a Fujifilm Quicksnap, since we found ...
0
votes
1answer
24 views

Minimum A/C Voltage to drive 12V regulator

Noob here. I have a 28V CT transformer. I want to use it to drive a 7812 and 7912 regulators. The data sheets says min. input voltage is 14.8V. How do I calculate what the unregulated DC voltage ...
0
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2answers
62 views

Wiring up a computer fan to a normal outlet, without using a computer PSU

Ive got a Rack that is getting abit hot and i would like to cool using fans. Ive checked out units made by Mid Atlantic c.£300 which are really expensive, but have also come across places selling fan ...
1
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4answers
123 views

Is it possible to have voltage across an inductor without having current through it?

Example : In certain cases in transformers we do assume so having zero current in the secondary but there is still a voltage across it due to mutual flux . Also we do similar things while calculating ...
3
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4answers
57 views

Transformer at primary winding

If transformer is coil (primary and secondary), then when we connect ac source across primary winding which is a nothing but a coil, so entire coil impedance will come across ac source and it will be ...
0
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2answers
54 views

Toroidal transformer

I have a toroidal transformer ac 230v with x2 25v. I am trying to power an old ham amplifier witch takes 28v 8amp (transistor) (blw77). I have now linked the transformer to an 8 amp bridge ...
0
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1answer
34 views

Question about transformer current

I got Step down transformer which reduces voltage from 230 VAC to 40 VAC ~ 100 amp. I can weld with it while having no problems. Also I got another one step down transformer which is three phase, but ...
0
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1answer
35 views

Replacing speakers' transformer [duplicate]

I have recently purchases new speakers and I have noticed a slight hum coming from the transformer, therefore I am considering replacing it. The transformer, used to power an internal amplifier, ...
3
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2answers
107 views

Transformer Inductance not taken into account?

When modelling an ideal transformer, why do we not consider the inductance of the primary and secondary windings of the transformer. Wouldn't this inductance affect the current pulled from the source? ...
0
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4answers
117 views

earth as a voltage reference

Why is the neutral point of the alternator hooked up to the earth which makes all the voltages of the lines with reference to the earth. Doesn't this makes us more risky to the shocks? I think we use ...
0
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0answers
20 views

The reflected impedance from secondary muti-windings

If a transformer with only one secondary winding, the reflected impedance from the secondary winding is $$ Z_{p,eff}=(\frac{N_{p}}{N_{s}})^{2} \times Z_{s} $$ This is a well known equation. But what ...
3
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2answers
74 views

Does transformer humming cause notable waste of energy?

AFAIK transformers hum because alternating magnetic field causes pieces of laminated core to slightly deform and vibrate and that is simply a byprocess of how transformers work. However for the same ...
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0answers
36 views

Capacitor and resistor in parallel to transformer secondary and bridge rectifier

I have more or less of a reference design at hand (only hardware, no schematic) where a 6k8 resistor in a 2512 package (imperial) and a MLCC are placed in parallel to the transformer secondary before ...
0
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0answers
59 views

Reason and mathematical explanation for 180 phase difference between input voltage and voltage across inductive coil

In an ideal transformer,why is the input voltage (say Vp) is 180 degree out of phase with the voltage across the primary coil (say Ep)?Vp leads Ip by 90 (according to many diagrams found on the ...
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0answers
15 views

How to calculate the mutual inductance

I would to know how to calculate the mutual inductance between the primary and the secondar coils of a stacked transformer which are separated with 'd' distance..
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0answers
53 views

Why is E_1 negative in an exact transformer equivalent circuit?

My electrical engineering professor has written the primary EMF with a negative sign in the transformer equivalent circuit: He has also written this equation relating to the circuit: ...
0
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1answer
66 views

How will I get the per-unit parameters when the data from the short-circuit test are shady?

Data from short-circuit and open-circuit tests of a 60-Hz, 100-kVA, 4600–230-V transformer are: VOC = 230 V IOC = 14 A POC = 60 W VSC = 172.3 V ISC = 20.2 A PSC = 1046 W Get ...
0
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1answer
49 views

Why do Flyback Transformers have C-I cores?

Usual transformer cores are either E-I or E-E. What's the reason for Flyback's being only C-I? Does it simply cut the cost?? I want to know if it would perform less if it were an E-I.
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0answers
32 views

Mutually Coupled Inductors

Hello there im working on a project in which i'm making a wireless mobile charger. Im using two mutually inductors for transferring power wirelessly i want to transfer 14V (AC) from my primary coil to ...
0
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1answer
53 views

Using a multi tap transformer

I'm new to electronics I have need some help with a power supply design I am designing. I currently have a 0-30 volt, 2 amp multi tap transformer that I am using for the above mentioned power supply ...
0
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0answers
40 views

Multiple Oscilloscope measurement in Multisim with small Variance

I have a design that consists of several stages, it's Dual DC Regulated DC power supply, using transformer, bridge rectifier, capacitor filter and regulator. We add the components one by one and each ...
2
votes
3answers
112 views

How does a transformer transmit power from the primary to the secondary?

I'm trying to get my head wrapped around transformer operation and in the process regretting the times I snoozed in my Electromagnetics class as a EE student back when I was a lad :) I'm looking for ...
0
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1answer
38 views

Connection of two identical transformers

I have a substation with two identical transformers 110kv/25kv single phase 50 hz usually one acts as spare. Now for some reason i want to charge my substation from secondary side i.e., 25 kv side ...
2
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2answers
275 views

Help me understand this load detecting circuit

I'm looking at this circuit: Which has come from here The claim is made that "it detects a voltage drop across a large bridge rectifier that acts as a high power shunt", which is referring to the ...
0
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0answers
15 views

Need Suggestions in winding 2x80vac 12amp Transformer

I want build 2x80vac 12amp Transformer for power amplifier ,i am confuse in calculating the wire gauge AWG for primary and secondary winding ..... need suggestions
0
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1answer
60 views

Boost converter for PV

So my two PV panels giving me an output of 40v, 1.5A. I am sensing both current and voltage of the PV output to give an MPPT duty cycle pulse. I want to boost the 40VDC to at least 400VDC and ...
0
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0answers
42 views

What parameters are key in selecting a transformer to pass digital data?

Looking to fiddle around with some digital signaling through transformers. Never done, so this is just to experiment and see what it looks like. For the purpose of digital isolation, what types of ...
0
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1answer
48 views

Spiral Core Transformer

Presently, I am reading about different types of transformer. I am stuck on 'spiral core or wound core transformer'. I didn't find any good explanation about it in the textbook I am reading. Searched ...