Help me with resistor calculations

[murali4757]

i want to use only 2 resistors.
I have variable source 0 to 400volts dc.(input)
i required 80vdc.(output).

pls tell me the answer,which resistors are used,and wattage

 

[alexan_e]

Re: Resistor calculation

please specify the output current and what you want to do with the output, you also say that the input voltage is 0..400 , if you use a resistive divider(2 resistors in series) you will always have a steady input/output division ratio (2/1 3/1 10/1 etc).
You will also have a voltage drop of 320v , if you multiply this with the current you need you get the watts but even with 10ma you will have 3 watts.
You probably need some kind of active circuit.

Alex

 

[pranam77]

Re: Resistor calculation

Enter the values your self and just press "Calculate" find the values yourself on this page.
**broken link removed**
But the current required is more critical before you calculate the divider network. When you say you need to use only two resistors, i presume you know what current you'll get.
Cheers

 

[nifleheim13]

Re: Resistor calculation

what is the output current?...you need to know it first...