• As a space-saving measure, power supplies for small electronics often reduce voltage at the wall socket, rather than inside the device.prise image by matteo NATALE from Fotolia.com
  
  Motorola's DCX3200 is a high-definition cable box distributed by several of the nation's biggest cable companies, including Comcast and Charter Communications. It operates on a significantly lower voltage than the 120-volt electrical service available at most household wall receptacles, and requires a power transformer to reduce the voltage and regulate current. In the case of the DCX3200, this is an external transformer, which alters voltage and current at the source.
  
  

Voltage

• The DCX3200 power supply can accept an input voltage of anywhere between 100 and 127 volts. It reduces the voltage to a steady flow of 12 volts.
  
  

Amperage

• The power supply provides the cable box with a steady flow of 2.67 amps, the amount that the DCX3200 requires to process a cable television signal.
  
  

Waveform

• The DCX3200 power supply operates at 60Hz, the waveform for the single-phase 110-volt alternating current available in standard household electricity systems.