overload trip...?
Input voltage = 75 -125VDC
out1 = 5V/1.1A
out2=+12v/0.6a
out3=-12v/0.6a total watts = 20w controller = TOP265VG
when i gradullay loaded with electronic load.the out becomes
input voltage mains voltage/loaded out2.voltage/loaded out3.voltage/loaded
98V 4.9275 /0.1A +12.022/0.1A -12/0.1A
98V 4.92/0.2A +12.01/0.2A -11.97/0.2A
98V oscillate/0.3A oscillate/0.3A oscillate/0.3A -----------------> oscillated voltage
Note: Suppose If i loaded mains winding alone upto 0.7A,keeping slave windings 0.2A loaded,there is no oscillations on the output side.
1)what is the reason for getting oscillation in the small load itself / how to solve it.............? (always facing this problem )
2)when got oscillation,even if i reduce the load to 0.2A,its does not get stable......? (attached schematic)
3) can i control main windings voltage by adjusting feedback reference resitor (5.1K in schematic) ...that is if output is 4.9 means,when i change resistor value can we make it 5V....?
Comments
pls find the attached schematic for your reference.
Do you have the rest of your design files availble? A transformer diagram would be helpful as would your PI Expert design files. Have you done any kind of control loop measurements yet?
-The Traveler
pls find the attached design file and transformer file .
And also i dont know ,how to test the control loop. can you pls explain the procedure to test the control loop.
If this overload trip problem solved,it will be helpfull us to develop more projects using PI controller IC.
I've attached a PDF of an article from Switching Power Magazine that does a good job explaining how to do control loop measurements for Power Integrations controller ICs that use current injection instead of voltage injection.
If you have some kind of oscillation going on, there are a few likely culprits:
- Control loop instability
- Noise coupling from other parts of the circuit into the feedback loop
- Bad transformer layout
-The Traveler
I'm having a hard time reading your schematic. Can you please attach it as a PDF? If you could also attach your PI Expert design files and your transformer documentation, that would be very helpful as well.
-The Traveler