Measuring AC Voltage from 60V-300V with Microcontroller

[asad1111]

I want to measure ac voltage raging from 60v to 300v using microcontroller i have figured everything else out except how can i use 220v transformer(to step down the voltage to measure) when input is 300v one solution is to use simple resistors based potential divider to attenuate 300v to 220v but there is too much power loss in resistors and i don't want to build a transformer for 300v any other solutions?

 

[berkeman]

I want to measure ac voltage raging from 60v to 300v using microcontroller i have figured everything else out except how can i use 220v transformer(to step down the voltage to measure) when input is 300v one solution is to use simple resistors based potential divider to attenuate 300v to 220v but there is too much power loss in resistors and i don't want to build a transformer for 300v any other solutions?

What is the source of this voltage? What frequency range is involved?

 

[asad1111]

Frequency is fixed 50hz

 

[berkeman]

What is the source of the voltage, and why do you want to measure its amplitude?

 

[asad1111]

source of voltage is autotransformer and i want to implement an automatic electronic tap changer therefore i need to measure its output voltage(which can go to 300v) to automatically change the taps of transformer to regulate the voltage