Wide input power supply with TNY278G using PIXS designer Problem
I have designed a three phase wide input (120vDC-790vDC) power supply which a TNY278G and a StackFET using your PIXS designer.
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In the first design, a 120v VOR results a 38/5 turn transformer.
During tests, I faced following issues:
When the input DC voltage reaches to 330vDC, after a few seconds the circuit starts an odd operation mode in which the switching circuit stops normal switching mode and starts working for about 75ms with high switching rate (~125kHz) then stops for about 2s and the start the same manner. As we reduced the input voltage it starts to work normal.
*** It should be considered that nearly before the odd operation mode starts, the switching frequency increase as I increase the input.
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In the second design, a 220v VOR results a 70/5 turn transformer.
During tests, I faced following issues:
When the input DC voltage reaches to 690vDC, after a few seconds the circuit starts an odd operation mode in which the switching circuit stops normal switching mode and starts working for about 100ms with high switching rate (~125kHz) and then stop switching for about 300ms and this happens for number of times and then stops for about 2s and the start the same manner.
*It should be considered that nearly before the odd operation mode starts, the switching frequency increase as I increase the input.
**The worst thing is that this mode lasts even when I reduce the input voltage to normal conditions or even lower and I should shut it down to make it works normal.
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In the third design, a 270v VOR results an 86/5 turn transformer.
During tests, I faced following issues:
When the input DC voltage reaches to 790vDC, the switching frequency increase little but the power supply works normal. Unfortunately choosing a270v VOR, imposes very high tension to clamping circuit and makes it very hot.
Comments
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Hi, did you have a chance to test the board, any update?
I did not see a obviouse mistake in the schematic.
Hi,
Thank for contacting PI.
I will agree that VOR = 270 VOR is relatively high. I would recommand you to design the supply with VOR less than 220V. For sure, the input voltage range is very wide for the power supply, the high VOR will enable large duty circle under low voltage which is good efficiency and enable to use small devices.
For your 120V Vor or 220V Vor design, it looks like the power supply stop by some faults (over voltage?) and then restart? I will recommand you to check detail the drain voltage, drain curreen, output voltage during power up or normal situation. You could also attached your schematic, I can have a quick check.