Hi,

Can you please describe the problem?

What do you mean by the coverter doesn't work? Do you men poor load regulation?

Regards,

PI-NANO

That means that the converter tries to start up but it goes in a fault mode after some cycles and treies to resatert after delay time.

Regards

Michael

Hi,

Since this is multiple output power supply, Loading one output while the other output unloded completely can make the output voltage go out of regulation limits on the unloded windings.

I would need you to probe Voltage waveform on bias winding and bias winding output voltage inorder to see whats going on.

Regards,

PI-NANO

Hi PI-NANO,

I made some measurements with the oscilloscope (s. attachment). It seems as that your assumtion is right.

How can I solve the problem? Is it possible to use a preload?

Is it possible to solve the problem with a other conversion IC family?

Our problem is that the descriped scenario is a possible scenario in our application.

A other problem in the application is, that the loads in the 5V supplies could be very

different. One supply powers a control panel with a TFT. The load varies strongly by

the backligth of the TFT (on/ off) while the other 5V&15V are in standby. The 15V supply is only used if the power MOSFETs

of a ultrasonic genarator are working (gate driver supply)

Michael.

Hi,

Can you try adding some preload on the 15V output and see what happens?

Regards,

PI-NANO