New answers tagged transformer
3
votes
Weight of an AC/DC transformer and wattage
I have a 66W USB (with PD) credit-card size (and about 10mm thin- including fold-out US/China style blades) supply that weighs 62g. Most of the changes have been evolutionary, but they sure do add up.
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0
votes
Weight of an AC/DC transformer and wattage
You have not included any more detail or pictures about the bigger and heavier power supplies/adapters, so it's not easy to give you a more accurate answer.
All I can tell you that the design over ...
- 5,536
1
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Weight of an AC/DC transformer and wattage
There are generally two approaches to these products.
A 'transformer' one will generally only work on 110-120 V (or 220-240 V) and operate at 50 or 60 Hz. These are older, simpler (much less ...
- 19.7k
4
votes
Would this configuration of microwave oven transformers work to make a simple arc welder?
The power you can get is limited by the fact that you're using a 125V / 15A feed. This limits you to no more than about 1200 watts (80% of 15A @ 125V.) That's about the power handling capability of ...
- 56k
0
votes
What does limit transferable power through a transformer?
What does limit transferable power through a transformer?
Often, temperature rise is the factor limiting the power transfer capability of a transformer. But you write:
my question is rather about ...
- 26.1k
0
votes
What is the risk when floating oscilloscope and DUT?
Even if you isolate the ground on the scope and you have the voltage high enough, you touch the scope and you get zapped (and fry the scope and you). Better to have the probes insulate. If you need ...
- 87.1k
0
votes
What is the risk when floating oscilloscope and DUT?
If you float the scope via an isolation transformer, the chassis has the same potential as your DUT. For example, you want to measure the current on a utility 480-volt line. You use a 10:1 current ...
- 978
1
vote
Accepted
Ethernet Transformer - What is the difference between these two versions?
The dashed line is not actually connecting the windings. It may be hard to see with this schematic layout, but actually it's connecting the cores of the two common-mode chokes. This is a standard ...
- 36.4k
1
vote
Accepted
Theory of high-voltage spark generators using pulsed transformers
You're on the right track. There are a couple contributions you've missed:
The MOSFET itself has output capacitance.
Turn-off dV/dt and dI/dt are never truly unlimited, of course; and even if the ...
- 43.4k
4
votes
How to accept 220 V input from this transformer pin?
No there isn't a way to make it accept 220V.
Also since you found in from the bin without specification or other context, you don't know if that is a mains voltage transformer or PA system transformer,...
- 164k
1
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Estimation of open-circuit inductance from the leakage inductance
In conventional (layered or banked) windings, leakage inductance is dominated by the distance between windings, or more particularly between wires of the windings. This is -- quite literally -- the ...
- 43.4k
1
vote
Accepted
Estimation of open-circuit inductance from the leakage inductance
After reading Andy's comment and thinking about the problem a bit more, I realised that increasing the gap length will not change the leakage much.
Instead, the coupling between the primary and the ...
- 38.1k
6
votes
Is magnetic flux in a transformer proportional to voltage or current?
The magnetisation flux is due to the sum of the ampere-turns in primary and secondary. That means it's easiest to think about it when the secondary current is zero, and the magnetising current is ...
- 171k
7
votes
Is magnetic flux in a transformer proportional to voltage or current?
You should make a clear distinction between magnetization flux (a nearly constant AC quantity made by the primary) and, the naturally cancelling fluxes from the primary and secondary windings (that ...
- 467k
1
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Magnetising Inductance / Primary Inductance
As far as I know Lm (magnetising inductance) is same as L11.
That is incorrect.
$$L_{11} = L_m + L_{k1}$$
So, they \$L_{11}\$ and \$L_m\$ differ by the primary leakage inductance \$L_{k1}\$.
why are ...
- 26.1k
-2
votes
What thickness wire should be used for 200-300 A?
The wire thickness for a current range of 200-300 amps is determined by several factors, including the type of insulation, the installation environment, and the run's distance. However, the following ...
- 1
0
votes
Power supply with output of 24V, 500mA
I am currently trying to design a power supply (non-isolated) [...] Can I use an autotransformer for this?
Yes.
But unless you already have such an autotransformer, it'd need to be custom part, and ...
2
votes
What thickness wire should be used for 200-300 A?
230V/40V = 5.75
If you have 130 turns on primary then you should use 130/5.75 = ~22.6 turns on the secondary (according to theory).
Reviewing the table here, you better be using larger than 4/0 (0000) ...
- 13k
0
votes
Is it possible to have a big difference between the ratio of primary-secondary voltage and the ratio of secondary-primary current?
voltage ratio Vp:Vs = 25:1. But ...the ratio of current Ip:Is = 1:6.67, which is too far from voltage ratio.
This can happen if the load current is very light compared to the rated load current of ...
- 26.1k
1
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Is it possible to have a big difference between the ratio of primary-secondary voltage and the ratio of secondary-primary current?
If you look for the classical transformer model you might find something like the picture below:
You will also note that there will be a sort of variety. For instance, \$L_s\$ and \$R_s\$ can be ...
- 1,380
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