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Does this transformer look like the secondary winding can be easily unwound to change the output voltage?

Chances are there is one each primary (my guess: 100 V…120 V) and secondary (17 V…20 V? 8.5 to 10?) winding on each coil former. If there were 17 V secondary windings and you only needed up to 6 VA, ...
greybeard's user avatar
  • 1,930
1 vote

Will an isolation transformer have a noticeable effect on mains hum? Also critique my DIY transformer idea

I am planning to build a transformer to isolate the device under test for my oscilloscope, so I don't accidentally destroy it. Something is amiss if you think you'll destroy a device under test with ...
Kuba hasn't forgotten Monica's user avatar
3 votes

Will an isolation transformer have a noticeable effect on mains hum? Also critique my DIY transformer idea

Usually isolating the scope is the worst idea ever. When people measure something that is dangerous like some device with unisolated mains using a scope, they forget that the scope metal parts and ...
Justme's user avatar
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0 votes

Dealing with High Voltage Low Current Transformer Inrush and bypassing a Thermistor

Don't worry about the transformer. It's just a lump of iron and copper! A transformer can handle overload conditions for some seconds before internal temperatures begin to rise dangerously. More than ...
Tim Williams's user avatar
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Dealing with High Voltage Low Current Transformer Inrush and bypassing a Thermistor

Sticking with a "mains frequency power supply", you could transform the series resistor before the reservoir capacitor to the primary side. This may result in a value suitable for the NTC: ...
greybeard's user avatar
  • 1,930
0 votes

Use a current sense transformer to step-up for a photoflash capacitor charger?

The current sense transformer datasheet specifies the inductance of the secondary and not the primary. I suppose that you can use a current sense transformer with Ls = Lp x N^2 if you find it. For the ...
cairdac_rd's user avatar
0 votes

What's the function of a feedback coil?

A feedback coil is used with the help of a transistor to allow a transformer to work with DC. As you might know, a transformer is fundamentally an AC component that needs a changing current (Since ...
Sebastian Gudiño's user avatar
3 votes

Calculating Core Loss Coefficient (Kfe) for Ferrite Materials

You can do it that way, roughly, but it's only a one-point calibration. β will be only an assumption. Better data requires more effort. As tabulated data are not provided, at this point I just ...
Tim Williams's user avatar
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1 vote
Accepted

Zero Voltage Switching (ZVS) in Conventional Full-Bridge DC/DC Boost Converter

I want to ask you that how can I do ZVS in my circuit? You can't get ZVS (or soft switching, in general, which covers ZVS and ZCS) in a hard-switched (I think this is what you meant by "...
Rohat Kılıç's user avatar
3 votes

Power transformer design calculations

You didn't state what mains frequency you are using, so I'm going to assume it's 50 Hz. The saturation limit for a mains transformer is given as URMS = 4.44 fNAB, where f is your mains frequency in Hz,...
winny's user avatar
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3 votes

Power transformer design calculations

You need to have a minimum number of turns to prevent saturation. The flux density equation is: $$ \hat B_e = {\hat E \over {\omega \, N\, A_e}} $$ Where: \$ \hat B_e \$ = peak flux density [T] \$ \...
qrk's user avatar
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Why doesn't current short through ground in a grounded secondary winding of a transformer?

It's an interesting question, makes you wonder. The primary of the transformer is across line-to-line (from the generator); its secondary is across line (transformer pin)-to-neutral (generator neutral)...
Alvin De Gracia's user avatar
1 vote
Accepted

SMPS transformer operation and replacement questions

is it possible to find a replacement transformer using these part numbers? No. Such transformers are custom-made for a given product. Those are internal part numbers. They don't mean anything to ...
Davide Andrea's user avatar
3 votes
Accepted

Power calculation of transformer

To state the obvious, you would not obtain a power of 40W; you would get 48.4W, which is 21% more than the rating of the transformer. Saying 1.2k is "about the same as" 1k is fine for, say, ...
vir's user avatar
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1 vote
Accepted

Primary impedance of the ideal transformer

In this case, why is there a primary impedance? And if there is, why don't we represent it with a resistor symbol? If you want to constrain the load to being just a resistor, then you can certainly ...
Fabio Barone's user avatar
  • 4,059
2 votes

Primary impedance of the ideal transformer

This is simply showing that the secondary load is reflected to the primary. Imagine it’s 1:2 with 10V on the primary and 20 ohms on the secondary. 10V becomes 20V becomes 1A or 20 watts. Reflect 20W ...
asdf30's user avatar
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1 vote

Distorted output waveform when connecting push-pull amplifier to transformer

I suggest focusing on getting the circuit working correctly without the transformer, ie: just the 300Ω load resistor. Then once that is done and circuit operation is well understood, then start to ...
Fabio Barone's user avatar
  • 4,059
0 votes

Can very high voltage and very low current AC produce strong magnetic flux in the coil?

Flux is defined as the integral of voltage over time. For a sine wave, we have: $$ \Phi = \frac{V}{2 \pi F}$$ To obtain "strong magnetic flux", simply increase the voltage and decrease the ...
Tim Williams's user avatar
  • 36.3k
0 votes

Transformer losses due to eddy currents. Why these losses are compensated by the transformer?

The thing is that the induced currents had their own induced field. Anyway, your initial assumption wasn't wrong. I'll try to use some simulations to support my arguments, but your question involves ...
Luiz Oliveira's user avatar
1 vote
Accepted

Experimenting with "high voltage" positive and "high voltage" negative using an ignition coil

Presuming the schematic for +ve HV is as follows: It's only a question of reversing the polarity at the primary to obtain -ve HV.
vu2nan's user avatar
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2 votes
Accepted

For a step down transformer, does the number of wraps in the secondary winding matter as long as the primary:secondary ratio is the same?

For instance, stepping down from 120 V to 5 V, the ratio would be 24:1. So does it matter if it is 24:1, 48:2, 72:3, etc.? Yes, it matters. Every transformer core has a required number of turns per ...
Math Keeps Me Busy's user avatar
0 votes

For a step down transformer, does the number of wraps in the secondary winding matter as long as the primary:secondary ratio is the same?

Well if it didn't matter then we would just use one turn on the secondary side, because that's easier and cheaper. So clearly there are other considerations. To understand them you need a more ...
Fred's user avatar
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