All Questions
14
questions
3
votes
1
answer
73
views
What are these resistors used in this flyback converter?
I'm new to designing flyback converters. I noticed resistors connecting the primary and auxillary coils. Can somebody explain the usage of these resistors for me.
The IC in this schematic is a CR1510. ...
- 31
1
vote
1
answer
64
views
Ground connections around bridge rectifier in flyback converter
I am designing a flyback converter and I am being told to make the ground net connections as shown in the image below.
I think this is colossally dumb because it eliminates PRI and SEC isolation. I ...
user224284
0
votes
1
answer
187
views
Flyback converter MOSFET driver
I am building a flyback converter to convert 230V AC to 20V DC using a microcontroller. So far my simple converter works, but I have to power the MOSFET driver such as HCPL-3101 from a secondary DC ...
2
votes
2
answers
612
views
Why doesn't SMPS controller VCC capacitor get fully charged to 310 V?
Most SMPS circuits have a startup circuit like the one in the schematic below:
The rectified 310 V goes through Rstartup1 and Rstartup2 to fill Cvcc to UVLO limit and the controller IC starts working....
- 663
2
votes
0
answers
3k
views
DK1203 Flyback SMPS - How does it work?
Has anyone come across a DK1203 SMPS like this? I've come across ICs like the FSGN300N that have a startup pin and aux coil to supply the IC. How would the self-supply circuit in the DK1203 work? In ...
- 71
0
votes
0
answers
34
views
LT Spice simulation error: 'Time step too small'
Could someone get this up and running? Tried all the possibilities but it does not seem to work still.
Here I am just trying to simulate the linked circuit here .. PMP7763 design reference
- 1,885
0
votes
0
answers
118
views
Flyback power supply - 132 kHz radiated magnetic field issue
I request your expertise on a radiated magnetic field around 132 kHz (low frequency) on a Flyback power supply.
I'm using the LNK3694 driver with a switching frequency around 66 kHz. Using a circular ...
- 1
2
votes
1
answer
453
views
Altium->Coupled Inductors
Im glad to be with you. I have question about coupled inductors in altium. I want to make a flyback converter and tried first as in Image 1 . I converted 310V DC to 12V DC as you can see. I wrote ...
- 55
4
votes
2
answers
967
views
Transformer overheating reasons
I am currently designing a Flyback-based offline AC/DC converter similar to the following schematic (with a few changes e.g. sync rectifier at the output). Everything works nicely but the custom-made ...
- 3,589
3
votes
1
answer
292
views
Flyback AC/DC based on UC28881 - TI's reference design - not working
I have build the AC/DC flyback converter according to TI's reference design but ist is not working and I am wondering why. By the way: I have build the 5 V version, so everything connected to T1:9,7 ...
- 582
0
votes
0
answers
710
views
Flyback converter with dual outputs (12V / 5V)
I came across the following flyback converter circuit, which has a dual output (12V and 5V), but I am unable to figure out why the secondary windings are connected in series.
Based on the datasheet ...
- 3,589
0
votes
0
answers
54
views
SMPS topology for combination of current controlled rail and fixed voltage rail
I'm looking at designing a LED driving power supply that can interface with a universal AC main input (~90VAC-260VAC) and produce 2 rails at the output; one a current controlled rail, and the other a ...
- 151
2
votes
0
answers
1k
views
Reducing AC/DC adapter (SMPS) output voltage
I have a AC/DC adapter P-1650-22 (used to power a notebook) laying around.
I would like to use it for other purposes, i.e. as a constant voltage source for LEDs.
The problem is, that the output ...
- 582
1
vote
2
answers
3k
views
What is the purpose of all these resistors and capacitors in this power supply? [closed]
This is the schematic diagram of pa-12 family laptop adapter. I think it is based on flyback topolgy but i have a problem understanding many things in it.
Actually, in many circuits in general ...
- 1,491