Power Conversion Guide
Voltage & Frequency
Current Capacity
Wattage Ratings
UL Listing
Transformer Class
Transformer vs. Solid-state
Types of Conversion
Safety Warnings
Abbreviations & Glossary
Conversion FAQ's
AC to AC Converters
AC to DC Adapters
DC to AC Inverters
DC to DC Adapters

 RadioShack Guide to Understanding Power Conversion

DC to AC Power Conversion (Inverters)

Purpose of Converter / Explanation of Operation

DC to AC power converters, or Inverters, are used to provide standard 120-volt AC power from a 12-volt DC source, such as a car or truck. Inverters allow you to power AC equipment that requires 120-volts and are rated in watts. This rating describes the maximum wattage that the inverter can provide.

Selectiing an Inverter

To determine which inverter you will need for a particular device, you will need to know the maximum wattage that the device draws. As with current consumption, the inverter must provide the required wattage as a minimum, but there is no harm in using an inverter which is rated at a higher wattage than your device requires.

If you have multiple 120-volt AC devices that you will use regularly, but not at the same time, you should select an inverter based on the highest wattage requirement, so that the same inverter can be used with each device.

If you have multiple 120-volt AC devices that need to run at the same time, you will need to add the maximum wattage for each device to determine the total wattage required.

Next, you should check to be sure that your vehicle can handle that wattage through the cigarette lighter or auxiliary power jack. Most cigarette lighters have a maximum wattage of 300 watts; however, some vehicles may be less. You should check your vehicle's owner's manual to avoid damage to the inverter and/or vehicle's electrical system.

Once you know what wattage that you need and have confirmed that your vehicle will support that wattage, you can purchase the inverter either on-line or through your local RadioShack store.


You should take particular care when selecting an inverter for use with devices such as televisions and monitors, as they have a "peak wattage" that is significantly higher than their "continuous wattage". This is because they require a much higher wattage in order to power up the than they require to run once they are on. If such a device is attached to an inverter that cannot provide the wattage required to start up, then the overload can cause damage to the inverter, your vehicle's wiring and/or the attached device. Always be sure to use an inverter which can handle the device's peak wattage.

  • Do not use a power converter of any type for critical equipment such as medical devices unless so advised by the equipment manufacturer.
  • Do not use a power converter of any type if you are not sure of your equipment's power ratings; contact the manufacturer for this information.

About RadioShack Corporation | Contact Us | Privacy Policy | Store Locator

Copyright© RadioShack Corporation 2004. All rights reserved.