Min Reflected Output voltage

Hi, 

In a previous post, I asked you about the min Vor and you requested the characteristics of our design but now new answer has been posted related to it. I write down here the previous posts jus in case you missed the last one.

rutalonso

"We have just desinged a power supply with the TOP256YN, and now, reading the application note AN-43

we have found that there is a recomendation about Vor (reflected output voltage). The  values recommended

80v<Vor<135V. With our transformer characteristics and output voltage Np = 42, Ns = 10 Vout = 12, we

only get a Vor of 50V ((42/10) *12 = 50V). If we want to increase the turns in the primary, we will have problems

with the insulation required for our product. 

My question is : can we have problems due to this low Vor? should we modify the transformer or can we 

work with the actual one?"

PI-KSAN

Thanks for Posting your question into forum , as the VOR is just our recommended value. Could you please send us the Input and Output(Power, voltage and Current) Specification, the transformer Core Information. We will validate the design and let you know whether you can use 50 VOR or not and explain you why?

ruthalonso

Hi,

Thanks for your answer. Attached you can find the drawing of the transformer used in our desing.

Regarding the input and output specs, the values are the followings:

INPUT

DC voltages:

Nominal Voltage à 110 to 250 Vdc

Min/Max Voltage à  88 / 300 Vdc

AC voltages:

Nominal Voltage à120 to 230 Vac

Min/Max Voltage à 102 / 250 Vac

OUTPUT

Voltage: ±12V

Power: min 30W

Currents: at 12v around 2A, at -12V around 0.5A

Thanks, and sorry for the insistence.