TinySwitch-III TNY279 design turn ON voltage set
Posted by: Rahul Pingle
on
Dear All, I have TinySwitch-III TNY279 10W design with supply voltage varying 93VAC to 265VAC and single ouput 12V / 1A.
How can I set / program the turn ON voltage at which the design will power up
Best Regards
Files
Hi,
You have indicated that the operating input voltage range for the design is 93VAc to 265VAC.
You will need to decide what the minimum turn-ON voltage needs to be. You will need to keep some margin betwen the voltage at which the power supply should turn ON and the minimum input voltage so as to be sure that your power supply will always be able to turnOn when you supply the lowest rated input voltage.
You will need to calculate the DC bus voltage at the output of the bridge rectifier for this input voltage and then you will need to calculate the resistor value (R5 in the shcematic that you provided) such that the current through this reisstor is 25uA at this DC voltage.
Please see page.4 of the datasheet for additional information.
Thanks and regards,
PI-Sarek