8
votes
Accepted
How Should I Model Eddy Currents in a Magnetic Core?
In general, it will be a distributed RL network, with an overall \$|Z| \sim \sqrt{F}\$ characteristic, at least over the range of interest. This is due to the skin effect, a diffusion mechanism, ...
- 27.4k
6
votes
Accepted
Transformer saturation value in volt-seconds
The transformer/inductor core saturation parameter is not a Volt.Second product, though it is frequently pronounced like that, perhaps to save syllables, assuming a single turn. It is a Volts_Per_Turn....
- 162k
5
votes
Accepted
Why does my flyback transformer simply refuse to work?
You may want to take a look at this circuit. That's a company that makes and sells power supply kits for Kirlian photography.
That circuit uses an LM555 as an oscillator. It then drives the ...
- 69.1k
5
votes
Isolation transformers and short circuits
Upstream = factory side of transformer.
Downstream = tested equipment side of transformer.
IF the transformer used is rated at far lower short circuit current handling ratings than the factory breaker ...
- 149k
4
votes
Isolation transformers and short circuits
As mentioned an ideal 1:1 isolation transformer won’t solve your problem. It will pass short circuit currents directly.
A real life isolation transformer may solve your problem if its leakage ...
- 779
4
votes
Flyback Transformer Winding Direction
In summary, windings that are wound in the same direction relative to another winding are in-phase and the polarity dots are placed on the starting ends of the wire
That's correct.
One thing to note ...
- 30.3k
3
votes
Accepted
Wurth transformer secondary pins on left and right side of transformer
Certainly looks that way. If you look at the chips it is designed to work with they are low voltage to low voltage so they may not have considered high primary-secondary voltage likely (though they do ...
- 384k
3
votes
How to measure flux in transformer in LTspice?
None of them is correct.
flux1 looks more reasonable because flux2 uses unswitched windings as well.
Remember the transformer ...
- 30.3k
3
votes
Identifying SMPS transformer
The inductance and resistance of a transformer can be measured with simple tools, for example a signal generator (sine preferred) and oscilloscope. At least an AC voltmeter, or preferably vector ...
- 27.4k
3
votes
Simple forward converter - strange demagnetisation
I think it's D1 reverse recovery.
It definitely looks weird in the first waveform. It seems clearer in the second. I'm not sure what exactly is going on, but it seems likely it has to do with the ...
- 27.4k
2
votes
Transformer saturation value in volt-seconds
I often find this value stated in Volt-Seconds
Volt-seconds i.e. flux, along with core properties including saturation flux density, becomes a transformer parameter. Volt-seconds also equals to ...
- 30.3k
2
votes
Transformer saturation value in volt-seconds
Correct, you need to know the winding reference. Usually it's labeled "primary", but datasheets are often vague about this, and one may wish to ask the manufacturer.
There's also the matter ...
- 27.4k
2
votes
What’s the explanation on why the outlets wires are on the same coils?
Mains frequency transformers are very often custom (in terms of units sold).
Even in an order of a few hundred you can get exactly what you want, at a lower price point than going to a COTS ...
- 384k
1
vote
Does all the current lag the voltage in an inductor or is it only a small component?
the way I understood a basic inductive circuit (voltage source + inductor) is that all the circuit current (Io) lags the voltage by 90 degrees.
That's correct, for a pure inductance.
If the circuit ...
- 162k
1
vote
Designing a power supply circuit for a DC motor speed control circuit
Here's one problem (another answer already mentioned a different one): You have connected an LED D8 directly across the output of the 12 V regulator, with no current-limiting resistor. In real life, ...
- 17.7k
1
vote
Designing a power supply circuit for a DC motor speed control circuit
Q1 should have a resistor in series with its base. If you have connected it up as shown it may be blown as a result of shoving too much current into its base.
Put a resistor in series with the LED.
...
- 511
1
vote
How do steel laminations reduce eddy current losses in a transformer?
The eddy currents are electrical currents that circulate in the transformer core, making it hot and wasting power. A big solid iron core will have a very low electrical resistance, and eddy currents ...
- 19k
1
vote
Why would an in series-opposition center-tapped transformer not be used to drive a circuit?
Sure, no matter how these two windings are connected, you can use one or both windings simultaneously as usual.
They just have one common terminal.
The two windings just happen to have common terminal ...
- 137k
1
vote
Accepted
Isolated flybacks in series to generate high-voltage
My general advice is to never connect anything but resistors in series.
If you do need 12 individual outputs, spanning from 0 to 600 V DC, there are some benefits of stacking the outputs of 12 ...
- 13.7k
1
vote
Can I convert a step down transformer to step up?
Yes, you can run most transformers backwards. But realize that you won't get much current at 240 VAC. The current rating is for the 12-0-12 side.
This is a 24 V * 3 A = 72 VA transformer. Your output ...
- 15k
1
vote
Accepted
Do Kirlian setups work with DC power?
According to this paper, Kirlian photography will work with DC.
There's mention of some differences between Kirlian pictures made using AC and Kirlian pictures made using DC.
The polarity of the ...
- 69.1k
1
vote
Accepted
Dropping the line voltage on an HH Scott 265A tube amplifier
Someone linked you over on Audio Karma. I am uploading what I have for Scott 265a bucking transformer
- 26
1
vote
What transformer should I use for high power switching?
To be safe you better galvanicly isolate your MOSFET from your Arduino with perhaps a small transformer of fast optocoupler. Do this to avoid electrocution. Now you can think about not blowing up the ...
- 14.3k
1
vote
Spooky multimeter AC reading using 1 lead
It is entirely plausible for your test leads to pick up currents from the circuit through air like antennas, especially with HF power electronics such as your cleaner.
Really high power high frequency ...
- 680
Only top scored, non community-wiki answers of a minimum length are eligible