The connectors used to connect the AC Adapter to the PowerBook are the same on several different models of PowerBooks. Although the connectors are similar there are electrical differences that prohibit you from swapping AC Adapters between the different PowerBook models.
It is a good practice to only use the AC Adapter recommended for use with that specific PowerBook. The PowerBook 1400 and PowerBook 3400 models can both use the same model AC Adapter. The AC adapters that they use are rated at 45 Watts.
AC Adapters that are supplied for the Duo models and the new PowerBook 2400 also use the same connectors. These adapters are rated at a lower wattage, 36 Watts and lower for some models.
Using these lower wattage AC Adapters with PowerBook models that require AC Adapters that supply 45 Watts is not supported by Apple Computer Inc.
PowerBook 1400 Series
M4895 or M4896* - 45 Watt AC adapter for Macintosh PowerBook 1400 series computers.
PowerBook 3400 Series
M4895 or M4896 - 45 watt AC adapter for Macintosh PowerBook 3400 series computers.
Note: Model M4896 has replaced model M4895. However, the two are interchangeable.
PowerBook 2400
M5937 - 36 watt AC adapter for the Macintosh PowerBook 2400c computer.
PowerBook Duo 210, 230, 250, 270c, and 280 computers
M7783 - 25 W power adapter.
PowerBook Duo 280c
M2693- 36 W power adapter which is fully backward compatible with all Duo computers only.
PowerBook Duo 2300c
M4174 - 36 W power adapter which is fully backward compatible with all Duo computers only.