ash
Full Member level 3

Hi all,
How can i design a well regulated 300V 200mA DC power supply? I found a circuit with lm317, it converts 9v dc to 250v dc without transformer, but my harddisk crashed. It was very useful circuit but i can't find the shematic again, named 317high.pdf . When i use capacitor to regulate 220v ac, i should use very big capacitor and it's more expensive.
How can i design a well regulated 300V 200mA DC power supply? I found a circuit with lm317, it converts 9v dc to 250v dc without transformer, but my harddisk crashed. It was very useful circuit but i can't find the shematic again, named 317high.pdf . When i use capacitor to regulate 220v ac, i should use very big capacitor and it's more expensive.