All Questions
Tagged with switch-mode-power-supply flyback
12 questions
17
votes
4
answers
14k
views
Why is flyback air gap needed for energy storage?
Why do so many sources say something along the lines "since a flyback transformer stores energy, an air gap is needed"? I have seen this reasoning in textbooks and app notes.
I thought air gaps ...
- 854
5
votes
1
answer
3k
views
Flyback transformer core heating up
I am designing a discontinous conduction mode flyback converter, 100kHz using UC3844 IC with the spec. 220V,50Hz to 5V 5A. The issue is that after testing it for an hour, the transformer starts ...
- 75
4
votes
1
answer
3k
views
Understanding flyback power supply with weird snubber circuit, and general function?
Hello fellow wanderers of the electromagnetic plains,
I'm looking to replicate the function of the below pictured reference design, just a simple 230VAC SMPS using an iW1700 chip (72kHz operation), ...
- 857
1
vote
2
answers
242
views
How can I make my flyback converter discharge immediately?
I'm using a flyback converter (220-100V to 19vdc) to power an electronics unit. But it doesn't discharge fast enough, this causes some relays to stay energised for a second or two after power supply ...
- 72
0
votes
2
answers
21k
views
SMPS schematic - transformer calculator
I found this schematic for a simple SMPS.
I want to use it to build a 24V/2-3A power supply for a soldering station.
How are the turns on the transformer calculated?
For the primary I can use
$$...
- 75
11
votes
4
answers
4k
views
What is a flyback?
Trying to find this answer is so difficult that I can't even tell whether What is the difference between a transformer and a coupled inductor? is asking the same thing.
Some reading suggests that a "...
- 2,462
5
votes
2
answers
811
views
Flyback power supply instability issue
I have created a switching power supply:
Input: 230 V AC
Output: 12 V DC, 1 A
Controller: UC3844
Topology: flyback
Switching frequency: ~ 100 kHz
Schematic:
When I start this power supply, output ...
- 5,528
2
votes
1
answer
180
views
Misunderstanding document about leakage inductance in a flyback converter V2
I m back again on this document ! :D The document teaches me a lot of things and I think it will help me to better understand the losses across the switching components. I really appreciate if someone ...
- 2,610
1
vote
1
answer
925
views
Flyback converter design using UC3843
I am designing a offline power supply which will 24 V as output with 2.5 A. I found UC3843 as better option. I used TI we bench tool to design my power supply. This is the schematic I got from it. The ...
- 11
1
vote
3
answers
2k
views
Why is the air gap important in a flyback transformer?
Why is the air gap important in a flyback transformer?
How should we consider the equivalent circuit of a standard flyback transformer?
If we are going to wrap all the windings of transformer to the ...
- 82
0
votes
2
answers
438
views
Flyback Frequency Foldback Mode (FFM) and Skip Mode
I would like to know why flyback needs to use Frequency Foldback Mode (FFM) and Skip Mode.
I did some research but I don't understand the details of what I've read. Below is a figure that I found in ...
- 367
0
votes
1
answer
2k
views
modify 30W LED driver for variable current output
I have a typical flyback converter for an LED chip rated at 30W output.
My goal is to change the brightness of the LEDs using a microcontroller.
If I am not mistaken (please correct me if I am wrong)...
- 121