low voltage ,circuit problem

[samnaik]

my modem circuit is not working with low voltage supply .i wanted to make it work at that voltage can i change the component of circuit that will work with low power

 

[shrtrnd]

Difficult to do with the modem itself. It's designed to operate at the voltage printed on it.
DC to DC (voltage) converter might work.
Why can't you use an adapter to obtain the voltage you need?

 

[samnaik]

ya it can be done with adaptor of 48volts ,because modem has three option two power it on

1)dc supply 48volts
2)ac supply
3)remote power feeding ie. i m powering the modem with power that has sent from other modem from long distance of 4.8km

i powering it with remote power feeding option
im sending 200v on line from one modem but volltage is dropping to 100volt for long distane
i wanted to know which part of the modem is responsible for powering on the circuit