kiransbaddi
Member level 2
Hello
I m developing on physiotherapy stimulator which works on AC. and output will be high voltage DC
input : 230V 50Hz
Output Voltage : 250V / 80mA . <0.5% of ripples
Switching frequency : 100kHz
SMPS transformer selected : EF20( suitable for 20W and above
To achieve above spec i thought to design a fly-back converter of 20W (250V*0.08mA), i have referred PI application note to design it. here are some problems i have found out
1. Designing snubber circuit. : The reflacted voltage will so high that it can easily destroy the MOSFET
2. Designing SMPS transformer : finding difficulty to select core /bobbin for such a high voltage
can anybody suggest me which is right topology i have to use use
note :
microcontroller PWM with additional driver circuit to drive MOSFET is used
MOSFET VDSS = 600V
I m developing on physiotherapy stimulator which works on AC. and output will be high voltage DC
input : 230V 50Hz
Output Voltage : 250V / 80mA . <0.5% of ripples
Switching frequency : 100kHz
SMPS transformer selected : EF20( suitable for 20W and above
To achieve above spec i thought to design a fly-back converter of 20W (250V*0.08mA), i have referred PI application note to design it. here are some problems i have found out
1. Designing snubber circuit. : The reflacted voltage will so high that it can easily destroy the MOSFET
2. Designing SMPS transformer : finding difficulty to select core /bobbin for such a high voltage
can anybody suggest me which is right topology i have to use use
note :
microcontroller PWM with additional driver circuit to drive MOSFET is used
MOSFET VDSS = 600V