RCDZ clamp optimization

Posted by: amigafan on 03/01/2018

Hello,
I have a 82W power supply with the below specifications:
Vin: 230VAC
Vout: 3X100V ( output one)
Iout: 0.17A
Vout: 6.2V
Iout: 5A
PI device: LinkSwitch6769E (eSIP)

I have attached a screenshot from the Drain.
With a charge of 294V and 0.158mA ( output one).
The 6.2V output is not charged

My question is whether it is possible to optimize the RCDZ Clamp, or if it's OK as it is?

Thanks in advance

Br amigafan

Files

DS1Z_QuickPrint19.jpg (71.99 KB)

LinkSwitch-HP_3X100V_0.17A_6.2V_5A_EE35.pdf (2.64 MB)

Comments

Hi amigafan,

You might want to check the transformer construction, the Drain Voltage Waveform is clipped. Check VOR.

Check also the the secondary diodes current waveforms, it might be caused by negative secondary current. This will result into clipping of Primary Drain Voltage waveforms.

Regards,
PI-Pike

Thanks for your reply. Could it have anything to do with the three 100V outputs is connected in series?
Regards amigafan

Hi amigafan,

Yes, check the switching waveforms of each output.

Regards,
PI-Pike

Hi Pi-Pike
I have attached a picture of the waveforms from one output( the other two are similar), 100V, 0.1A.
With my uncalibrated measuring instruments I have measured an efficiency of 90-91%, very impressive.
Regards amigafan

Attachment	Size
Waveform of outputs,yellow before and blue after diode, no post filter. (86.01 KB)	86.01 KB

Glad to hear!