The following information is provided to help understand American Flyer Transformers.

Most American Flyer "S" and "O" engines were designed to run on AC or Alternating Current. Although, the motors are what is referred to as "series wound", so they can also operated on DC or Direct Current. Maximum voltage is 15 to 17 volts.

American Flyer engines also were made that would only run on DC, those engines have a "DC" after the engine number. Engines that have an "AC", after the engine number will run on both.

All American Flyer Transformers are AC. The DC versions are called Rectaformers.

Early American Flyer "HO" engines ran on AC, while later versions run on DC. In general the power units for the HO are called DC power packs.

The size of transformers are rated in watts. The smallest being 25 and the largest being 300 watts.

Most American Flyer boxed sets came with 25-75 watt transformers.

Choosing the right size transformer

When choosing a transformer it's important to calculate the power requirements you need. A good rule of thumb is 25 watts per motor. So a small engine like a 302 running on a small loop of track will only requires a 25 watt transformer. Larger engines or dual motor diesels will require twice the wattage.

The next thing to consider is size of your layout. You will need to add wattage the larger your layout is and for accessories, lights etc.

Small Steam Locomotive                     15-25 watts
Large Steam Locomotive                     25-35 watts
Diesel Switcher                            15-25 watts
Large Diesel A & B Unit                    25-40 watts
Each Lamp                                      3 watts
Automatic Accessories                      10-25 watts
Operating Accessories                      20-40 watts                  
 

AMERICAN FLYER TRANSFORMER DATA
Transformer # A. C. Volts  WATTS  Frequency  Variable Voltage Range Fixed Voltage

    1            115    25 Watts  60 Cycles         7-15 Volts
    2            115    75   “    60   “            7-15   “           15 Volts
    4B           115    100  “    60   “            7-15   “           15   “
    8B           115    100  “    60   “            7-15   “           15   "
    12B          115    250  “    60   “            7-15   “           15   “
    19B          115    300  “    60   “            7-15   “           15   “
    30B          115    300  “    60   “            7-15   “           15   “

More information is available in our American Flyer Trains Photo Gallery and items we have for sale are listed on our Trains for Sale page.