3-Way Light Bulbs and Dimmer Switches

Can 3-way light bulbs work with a Dimmer Switch?

By Mark J. Donovan




A 3-way light bulb is effectively two light bulbs in one. 3-way light bulbs are specially constructed bulbs that contain two filaments. Each filament is rated for a different wattage to produce a different level of light. They are designed specifically to work in 3-way lamp sockets, which have multiple contact points to control the 3-way light bulb.

When a 3-way light bulb is used in a 3-way socket, the bulb can be controlled to produce three levels of brightness.

When the lamp is switched once the lower wattage filament is turned on to produce a dim light.

When the lamp is switched a second time the higher wattage filament is turned on to produce a medium light. When the lamp is switched a third time both filaments are turned on resulting in maximum bulb brightness.

3-way light bulbs can be used in non 3-way light sockets however the bulb will only operate off of its default filament setting.

3-way light bulbs are designed as an alternative to installing a dimmer switch. 3-way light bulbs can be used in a lamp that is controlled by a dimmer switch, however there are some limitations and redundancy to doing so.

First, there is no way to send a control signal from the wall dimmer switch to the 3-way light bulb lamp to switch between the different filament settings.

As a result the 3-way light bulb will only be able to be dimmed on the particular element that it is set to via the 3-way light socket lamp.

Second, the dimmer switch provides the ultimate in brightness level control to a light bulb. As a result, there is no reason to use a 3-way light bulb in a dimmer switch application.


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