On Board - Combination Alternator/Starter
Small brush-type Starter/Generator

Uses a two speed transmission.

Prototype Brushless Alternator/Starter

Uses 3 Phase controls

Combination Starter-Generators or Starter-Alternators make sense in some applications. The choice of a combination unit or separate modules depends on the starter torque required and the alternator or generator power required. If the starter torque required is significantly larger than the alternator power needed, it is usually lighter and less complex to use a geared starter module and a direct drive alternator.

The two speed transmission has some significant drawbacks (noise, maintenance and reliability) and is normally only used on short duration, limited life vehicles.

When the starter torque and alternator capacity are fairly close, a combination starter-alternator may be a good solution. Generally, the unit will be physically larger and heavier than a starter or alternator alone, but may be lighter overall than both modules together.

Please contact us for a more thorough discussion of the merits of each type of design.


Sullivan Products
8950 Yellow Brick Rd
Baltimore, MD 21237
Phone: 410-732-3500
Fax: 410-327-7443