TNY290 does not start
Attached is the design created using PI Expert and TNY290 for +/-6V DC supply. The power supply starts only for a few cycles and stops immediately before any voltage is developed on the output side. Please comment.
Regards,
Madhuri.
Comments
Many thanks for the support.
1.I tested it at 200V & 240VAC
2. The waveform of voltage at drain attached. I don't have a current probe.
3. I reduced the capacitor to 1000MFD but no difference.
4. All components are correct.
5. The transformer design attached.
Regards,
Madhuri
| Attachment | Size |
|---|---|
| DS0001.png (7.87 KB) | 7.87 KB |
| DS0000.png (7.68 KB) | 7.68 KB |
| TNY290PG 6V 3.1A, -6V 0.15A transformer.pdf (27.86 KB) | 27.86 KB |
Hi,
I did not find obvious issues in the design. Are there any warnings shown in the PI expert design? Do you know if the power supply went into auto restart? You could check the drain voltage in a long time scale, then you know how long the power supply switching before stop switching.
Hi,
Here are few things that I propose to check:
1. What is the input voltage of your test? If you apply higher input voltage, does it operate correctly?
2. Possible to check the waveforms of the drain current and drain voltage during the few cycles?
3. If you could decrease the output capacitors value for experiment purpose, does it work correctly?
4. Any components on the boards is mismatching the schematic?
5. If you could share with me the transformer design spec, I am glad to check it for you.
Best Regards
Xin Li