>> Is it possible to take that 1.5 volts, step it up to 5 volts, and  
>> make
>> it put a steady 25 mA through the resistor?

Note that by your conservation of engery, stepping up the battery to  
5V to push 25mA
(0.125mW) through the resistor will require that the current OUT OF  
THE BATTERY be at least 83.3mA (still 0.125mW)   The step-up doesn't  
happen by magic...

BillW

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